Oz Report
topic: carbon fiber
140 articles, page: 1
Fixing Carbon Fiber Base Tubes »
Haven't heard if Wills Wing is selling them any more
carbon fiber|Gregg "Kim" Ludwig|Wills Wing|Wills Wing T3
I had a crack in my Wills Wing T3 carbon base tube so I had Gregg Ludwig take it in to The Frame Doctor for me as he lives right near by and was hauling it back to Florida for me from Casa Grande, Arizona and the Santa Cruz Flats Race.
https://www.facebook.com/FrameDoctor911/
Joey Robison is the Frame Doctor:
This is my base tube:
Click the picture above to see the much higher resolution version.
Discuss "Fixing Carbon Fiber Base Tubes" at the Oz Report forum link»
4 topics in this article: carbon fiber, Gregg "Kim" Ludwig, Wills Wing, Wills Wing T3
Batten Carbon Fiber Reinforcement
DIY - after market
battens|Battens|carbon fiber|Carbon Fiber|Ian Duncan|Steven "Steve" Pearson
Carbon reinforcement for the battens of any hang glider, both 10 mm and 12 mm. The reinforcement guarantees better performance, strengthens the battens with only a few extra grams. For information: «darkblade55» cell.+39 3488230794 (whatsapp).
Ian Duncan writes and Steve Pearson agrees:
The big problem with this is that the carbon sock is all off axis fibers and therefore does very little work for weight added. You would be far better adding well bonded unidirectional fibers. If you are going to use 'sock' then using a far larger diameter sock compared to the diameter of the batten and stretching it lengthways would be preferable as this would pull the fibers closer towards the 0 axis of the batten.
6 topics in this article: battens, Battens, carbon fiber, Carbon Fiber, Ian Duncan, Steven "Steve" Pearson
Carbon fiber tips for U2 and Sport 3
Carbon fiber tips for U2 and Sport 3
They are in development
carbon fiber|David Aldrich|Facebook|Wills Wing Sport 3|Wills Wing U2
David Aldrich writes:
Yesterday, I just finished getting the tips figured out on a U2. We still need to flight test it though. I have enough sample material to make a few more sets. They are Carbon Fiber too.
They will be available on the S3 and U2. Probably not on the S2 as they require additional Velcro to be sewn onto the sail.
The existing U2's will also require some additional Velcro to be sewn on the sail now that I think of it. We can do it here at the factory without removing the sail from the frame, but we would need the glider. A good excuse to come fly with us at Crestline this summer!
Discuss "Carbon fiber tips for U2 and Sport 3" at the Oz Report forum link»
5 topics in this article: carbon fiber, David Aldrich, Facebook, Wills Wing Sport 3, Wills Wing U2
Breaking the carbon cross bar
Three views
carbon fiber|video
Igor Snisarenk writes:
Young pilot Igor Snisarenko breaking cross bar of his Aeros Combat 2 while trying to make series of loops. Video made from three different cameras. Flight made in the Caucuses mountains.
Igor's comments in the end of the movie are (translated from Russian): "After long practicing of making wingovers and loops, the excessive speed and the wing overload affected the strength of the carbon crossbar. Cross bar collapsed when the glider was on the way to the second maneuver of the series.
It took five sec and 80-120 meters of altitude for the reserve chute to open. Very useful positive experience. This won't stop me from continuing making aerobatics.
Meanwhile Igor announced aerobatics courses where he is teaching aerobatics.
Discuss "Breaking the carbon cross bar" at the Oz Report forum link»
2 topics in this article: carbon fiber, video
ATOS tips
A round up of a few useful ATOS tips from the Oz Report.
Mon, Aug 30 2004, 6:00:03 am GMTA.I.R. ATOS VX|carbon fiber|tip wands
1. A little bit of shoe goo on the tips.
2. Double the wrap on the bungees on the spoilerons.
3. Place 3" by 4" sail cloth patches on the top of the sail when it is brand new (or later) at the junctions of the first two ribs and the horizontal seam. Perhaps in other areas near this area also. This is to prevent damage to the sail cloth when the ATOS is folded and carried. I have tried for years to get AIR to address this sail damage problems. Perhaps they can't figure out how to do it.
4. Put green and red dots on the appropriate ribs on the ATOS VX - the ones that come undone.
5. To more easily place the carbon fiber shells on the tips, fold back the sail cloth three or four inches to expose the carbon fiber. Put the shells inside the sail and align with the black mark on the Velcro at the tip end of the aluminum tubes. Make sure that the shells are over the d-cells. Then you can just install the tip wands and pull tight.
3 topics in this article: A.I.R. ATOS VX, carbon fiber, tip wands
AIR ATOS - VX (part 1) »
Thu, May 6 2004, 1:00:00 pm EDT
My impressions of the new glider from AIR.
A.I.R. ATOS|Belinda Boulter|carbon fiber|Felix Ruehle
http://www.a-i-r.de/pages-d/f_a_01.htm
Well, first of all I am, of course, very happy to be flying on and winning the latest competition with the AIR ATOS VX. Given my dismal showing at the Flytec Championship (people were approaching Belinda to ask if there was something wrong with me), it is a true testament to the superior performance of the VX that I was able to win the South Florida Championships.
The AIR ATOS - VX with its curved up tips is a very beautiful glider to see in the air. You could always spot Alex during the Flytec Championship, high over your head.
The VX, while in prototype, came in two versions - single and tandem. The tandem version, which is now the standard version, is heavier and beefed up to handle two people hanging from the carbon fiber keel. Alex brought the standard (tandem) version to fly by himself at the Flytec Championship and that is the one that I have now.
The VX is listed at 93 pounds (42 kg), the V is listed at 82 pounds (37 kg), and the C is listed at 73 pounds (33.5 kg). I have weighed my C and it is 73 pounds, I haven't weighed the VX yet. I didn't find the VX to be particularly heavy. I was able to carry it around pretty much like I did my C.
These weights do make one wonder what changes they made between the C and the V. The differences are not obvious, so I assume it is in the carbon fiber lay-up. Maybe they are just counting different things (bag or not?).
I asked Felix Ruehle about this. He wrote:
The new control system where the spoiler cable is attached inside, has 3 extra steel pulleys. The brake away safety parts at the down tubes add some weight. The sail is reinforced at the trailing edge and tip in comparison to the first ATOS. The Spoiler and Flap are painted white. The first spoiler were little lighter.
Still, these changes don't seem to be enough to make such a large difference in weight between the C and the V. The weight for the V includes the tail, which the weight for the C did not.
The tips of the VX are formed with a long aluminum tube and a thin carbon fiber shell that creates the leading edge. This is essentially just an extension of the tips found on the standard ATOS (or C or V) model with the outboard tube tilted upward a bit.
There is an additional rib that is jammed in placed (not connected) to the leading edge) tube to continue the airfoil profile further out to the 46 feet wing span (vs. 42 feet for the standard model). I assume that the tips are canted up to relief any force on them while the glider is on the ground.
Felix writes when I ask him about this:
The main reason is to have enough clearance at take off. Wings with higher aspect ratio tend to tighten turns. With the additional dihedral of the outer wing the glider fly stable in turns.
The glider takes a little bit longer to put together than the standard version, basically because of the additional requirement of putting in the longer carbon fiber leading edge shell and the additional rib. Otherwise it is the same as the V.
My VX came with a carbon fiber keel (the part in the sail), and without a whack tube. There will be a foam core to replace the tube. The carbon fiber keel is standard. The d-cells and the ribs have been beefy up on the VX. Otherwise the hardware was very familiar.
The stinger on the VX is longer than that found on the standard model, and this means that the tail is further back. I assume that this adds to the stability of the glider in pitch as there is now a longer lever arm from the center of lift to the tail.
I flew both my C and the VX with the longer stinger and perceived a difference in how the gliders reacted to pitch movement with more apparent dampening. This appeared to give the glider a steadier feel.
The VX is not yet certified but AIR has run the pitch tests at the DHV for it and it has passed those tests. You can read more about it at the AIR web site (see the URL above). I suggest looking at the German version of the AIR web site, as the English version is not up to date.
4 topics in this article: A.I.R. ATOS, Belinda Boulter, carbon fiber, Felix Ruehle
AIR ATOS VX
Thu, Apr 29 2004, 2:00:01 am EDT
The light air machine.
carbon fiber|Manfred Ruhmer|Oleg Bondarchuk
There were a few questions on the rigid wing list:
1) How does the glider compare flying side by side with a "C" model. Does it accelerate as easily or is it a slower flying model (due to the larger wingspan)?
When I flew it it was slower flying, but I think I will move my hang strap a little more forward, just to have more pulling power when I enter the thermals. I could easily fly it at over 50 mph, but I didn't try pulling into sixty mph as there was a lot of bumps from the thermals on final glide.
It accelerates quickly if you let off on the flap rope and go to full race mode thereby. If the bar pressure gets a little light for your taste, pull on a little bit of flap.
I flew it without any ballast at all as I'm tired of carrying ballast after two years of doing so. I think that it would benefit from ballast.
2) What about the turn rate? Does the additional span interfere with the responsiveness of the glider?
Yes, it is slower to turn and "feels" like a bigger glider. It has an additional spoileron on each side to help the glider be a bit more responsive.
I enjoyed the turn rates and it felt great in the thermals. Oleg complained that I was flying too flat, but he wasn't out climbing me.
3) How are the angled tips put together (do they actually come off or are they a one piece mold on the leading edges)? Pictures would be nice here if anyone has any of the glider being put together/torn apart!
Tubes coming out of the d-cells. Long reinforced carbon fiber pieces to form the leading edge. It is pretty easy to put the glider together. Not that much more difficult than a regular ATOS. Fits in the same bag.
There is a new glider bag, much lighter and a little bigger to go on easier.
4) What about the hook-in weight that Alex was using (how much ballast did he carry and what was his hook-in weight)? Was it necessary for him to disperse the ballast before landing?
Alex is light and carried only four kilograms of ballast. He doesn't like ballast. It was not disposable ballast. I have landed many times with twenty two pounds of ballast without the slightest issue.
Am I correct in reading that conditions during this championship were "mellower", thus giving the VX an advantage because of larger sail area? Did anyone get a chance to fly side by side with it on the stronger days where pilots could fly more aggressively and if so, can they provide us with a performance comparison?
I didn't feel that the conditions were at all mellow. But this is Florida flying and it isn't the mountains or Texas for that matter. No 2000 fpm thermals. There were rough edges, but not extremely rough.
So far Alex has not said whether he will fly the VX in the mountains at the Worlds in Greifenburg. He feels that it may be too rough for it there, where you don't care so much about a fantastic sink rate (100 fpm). He wouldn't want to fly with ballast and may feel that he needs to if he flew it there.
That said, Manfred Trimmel flew a lighter weight version of the VX (not made for tandems and without the extra carbon fiber in the d-cells) at Bassano and won the first day.
The VX is the perfect glider for Florida and Zapata. I also think that it will do well in Big Spring, perhaps with some ballast. I will be flying a V or a C at the Worlds.
The VX was designed to be a tandem glider or for pilots who hook in over 220 pounds. There is the version with tandem reinforced d-cells and I have a carbon fiber keel on this one.
On my first flight I felt that the glider was much steadier than my sports car like ATOS - C. While I can't say exactly what steadier means, it made me feel more secure.
I get nervous putting at ATOS up on a tip unless the lift is really strong and tight, so I tend to fly the thing pretty flat in thermals. I don't know exactly what it is that bothers me, but is feels like the inside wing is dipping down.
It seemed that I was flying slower in thermals in the VX than in my C. Maybe just because my hang point was further back than it should have been.
I was climbing and gliding with Oleg, Brett and Kurt on the first day, and really didn't have any rigids around to compare much with. Maybe I'll get more chances later.
Discuss the VX at the Oz Report forum
3 topics in this article: carbon fiber, Manfred Ruhmer, Oleg Bondarchuk
Aeros Combat L »
Wed, Apr 14 2004, 3:00:02 pm EDT
I like it, and it should land great too.
carbon fiber|Julian Harman
Julian Harman «Julian.Harman» writes:
Took delivery of the first combat L 14m in the UK. Have to say very impressed so far, only managed 1.5 hrs yesterday on it but initial indications are promising, very promising. Build quality, in my opinion is up with the best. On the hill, pilots commented on this, especially the fittings.
In the sky, the glider flies very neutrally, noting quirky at all. Turn co-ordination is beautiful, a bit like the older Airwave gliders where the bar is out a little, the glider turns totally neutrally on shallow bank, with very slight high siding on tighter, which tunes out with a smooth VG action.
Sink rate - gets to the top when you want to (even me) and glide, well had no real instruments but it seems to be amazing. On full VG could turn it over 30 mph, and also flying slower.
Landing - well my mistake I flew to near a dry stone wall and had to land cross wind, rusty but the glider even with me on my belly did not 'pile in' as it flies very slowly.
I have to say that it appears Aeros have built a great glider, for the comp and more advanced intermediate. I felt right at home on it. No aerotowing yet but the full speed range, from stall to flat out showed no yawing, no turns, and very easy to keep in a straight line, even on the speed bar. So hopefully should be the same on tow. I'll find out soon.
The only build part I did not like was the carbon fiber battens, these are actually carbon fiber and aluminum, crimped onto the carbon fiber. I asked Aeros why they did this, as it look a little crude. They said it's the best way to build for light weight, simple and also the aluminum is needed for aerofoil flexing as the VG is pulled on. Carbon fiber not suitable for this. The crimping does not show in the aerofoil - at all. Sail - no ripples flat out with full VG.
Considering this glider is some £2,000 less than the same spec Litespeed here, it's a great value comp machine. I still think landing it needs a flare at the right point, the window may be smaller than say a Talon, but I have not been able to really test landings without a dry stone wall in my way!
Discuss the Combat L at the Oz Report forum
2 topics in this article: carbon fiber, Julian Harman
Some foreign gliders are still inexpensive
Fri, Mar 26 2004, 3:00:02 pm EST
The Aeros gliders still come in as the least expensive.
carbon fiber
G. W. Meadows «gw» writes:
I've noticed in the last few issues of the Oz Report that you have been comparing the costs of gliders (the Icaro at $9100) and the Litespeed (price not mentioned). You had suggested that folks take a look at one of your sponsors (Wills Wing). According to the Wills Wing website (www.willswing.com), their fully blown Talon (in the customer's choice of colors) retails for $6343 - a noticeably better price than the ones mentioned.
I would like to also mention the Aeros gliders. A Combat L - in customers choice of colors with all the same options as the Talon retails for $6095 (5% less). In addition, the Combat offers a couple of options not available on the Talon including carbon fiber ribs for lighter weight and a greater performance envelope as well as a non-gel coated crossbar for further weight reduction.
The Combat L uses basically all the same materials as the comparison gliders - practically all major parts (frame and sail) of the gliders comes from Europe - many of the materials from the exact same suppliers. We even buy our upright stock from Wills Wing.
We at U.S. Aeros are very proud of the fact that we have been able to keep our prices still the lowest in the industry since the day we hit the market in 1996. Even with the tremendous rise of the Euro in relation to the Dollar over the last 18 months (a near 50% gain), we have still been able to keep the Aeros products a tremendous value.
The Talon (just like all the European and Australian gliders) are excellent products and I'm not saying that we're better by any means. But a conversation about glider pricing just isn't complete without bringing up the Aeros line.
The cost calculations:
Baseline glider:
1. All Mylar body (we are talking top performing gliders here)
2. Super streamlined control frame with carbon ergonomic basetube
3. Leading edge inserts
4. Custom Colors/split panel
Combat L any size 13,14,15m
$6095
(source: www.justfly.com)
$5995 includes 1,2,4
$100 for #3
Talon
$6343.76
http://willswing.com/prod2.asp?theClass=hg&theModel=talon#options
$5875 includes # 2 kinda (not sure about carbon basetube - but don't think it's included)
1. $150
2.
3. $168.76
4. $150.00
Litespeed S 4.5
$7432.50 (http://www.moyesamerica.com/forms/pricebook.pdf)
$6295 includes none of 1-4
1. $192.50
2. $650.00
3. $195
4. $100
1 topic in this article: carbon fiber
Flying flex wings in Oz
Wed, Feb 11 2004, 12:00:01 pm EST
I flew the Airborne Climax 14 and the Moyes Litespeed 4.5 with carbon fiber outboard leading edges and their new "shadow" Mylar sail cloth. I decided to fly flex wing gliders in Australia because I felt that I should highlight the two major hang glider manufacturers in Australia during their competition season. I traded ads space for use of their gliders during the competitions.
carbon fiber|Ian Duncan
I thought that it was crazy to bring (at great expense) a rigid wing to and then back from Australia when there were such quality manufacturers in Australia already. Moyes and Airborne are world class hang glider producers and it has always been great working with both of them.
While I've been asked which glider I thought was the best performer, I really have no way to know that answer. The performance of each of the gliders was overwhelmed by my "performance" and the conditions of each of the days on which they were flown.
I did feel that both gliders were a little "big" for me, with the Climax a little "bigger" than the Litespeed 4.5. I would have liked a smaller control frame in both gliders to make launching a bit easier, but you need that big control frame for weight shifting. I wanted the control bar higher off the ground.
I'd love to try smaller versions of both gliders, and perhaps I will have a chance this spring in Florida. I bet I get a chance to try out the Aeros Combat L also.
I really loved how easy it was to put in the tip wands on both of the gliders. The Litespeed was very slightly easier. I did use the kick stand on the Litespeed to lift the trailing edge of the sail up making it easier to put in the battens. Sure, it is still a problem because it is unstable and the glider can fall over in a little bit of wind, but it was awfully convenient.
I liked the use of more carbon fiber parts in the Litespeed, but I assume that the cost really goes up. These are optional, but I bet Ian Duncan wants you to purchase them.
Speaking of costs, the Australian dollar is around $0.75 to the US dollar, up from $0.55 a year ago. This means that Airborne and Moyes can purchase 7075 aluminum more cheaply, but the cost of an Australian glider may be going up.
Because I had the wrong battens for the Climax at the Bogong Cup, I didn't have the opportunity that I wanted to get to fly the Climax 14 again. This would have given me a better idea of the performance differences if any.
I did like the fact that Moyes numbered their battens so that it was just that much easier to pick up the right battens when assembling the glider. A simple thing, but just that much more user friendly.
I never did get use to the Litespeed VG line and how much I line I had to pull on to get to even 3/4 VG. I never really got that much on. Unfortunately I didn't get to check the Climax VG after I flew the Litespeed as I didn't check the pulley on setup on the first day of the Bogong Cup and the VG line stuck.
The VG setting appears to be very important. I found that I was knocked sideways and slid downwards a few times when I entered into thermals with the VG at a little over half on the Litespeed. I didn't notice this on the Climax, but that could have just been the circumstances.
It was a bit unnerving to be knocked around so much when the VG was on, but as soon as I got it off I was able to handle the thermals. The discussion that I heard about this issue during the meet was to go with the turn and try not to fight it. My natural reaction was to try to climb the higher downtube and roll back into the thermal with the VG still on. Hard to do.
I'd love to hear more from other flex wing pilots about this issue and how you deal with it.
I'll have more to say about flex wing performance in the Australia competitions and some reflections on lessons learned (hopefully) in the competitions in later Oz Report issues.
Discuss flex wings at the Oz Report forum
2 topics in this article: carbon fiber, Ian Duncan
Tip Wands »
Sat, Jan 24 2004, 1:00:04 pm EST
carbon fiber|Ian Duncan|Tom Lanning
Tom Lanning «tom.lanning» writes:
In Oz Report v8 #14 a pilot wrote in "You'll probably hear from Tom Lanning, though. Same thing happened to him as you except I think his broken wand went through his sail."
I did have two tip wands break on a new Litespeed 4 last spring. One tip wand broke cleanly a few inches outside the wand socket on the leading edge and punched a small hole in the sail on the leading edge. The second wand broke while I was flying.
Unlike your incident, the glider developed a progressively worse right turn until I was hanging on the down tube just to maintain level flight and was seriously thinking about throwing my parachute. Luckily it was a breezy day in Florida and I was over large pasture fields. I thought that if I could just keep the glider into the wind on final, I could fly it into the ground without much speed.
I managed to pull off a respectable 3 step landing even as the glider wound around to the right. Unlike yours, this tip wand unwound in the center with a spiral splintering that reached about 1/3 of the way to either end. I would not say the wand became "unwrapped", but the pattern was similar. Both of my tip wands were fiberglass.
I know of at least two other Litespeed fiberglass wands that broke on the ground while the glider was just sitting unattended. One of the pilots even flew the glider and landed complaining of a "new subtle turn" in his glider!
I ended up flying another Litespeed 4 last summer and fall and had no problems with the tip wands and they are still relatively straight.
(editor's note: It was great to hear from Ian Duncan about the carbon fiber tip wands that he now produces for Moyes and how straight they are. I found mine to be perfectly straight after flying with them. This is really a big improvement and Moyes and Ian are to be congratulated for coming up with this method. I didn't notice any problems with the Climax tip wands and I will check from over the coming week.)
Discuss tip wands at the Oz Report forum
3 topics in this article: carbon fiber, Ian Duncan, Tom Lanning
Aeros Combat »
Wed, Jan 21 2004, 12:00:02 pm EST
calendar|carbon fiber|Kevin Carter|Oleg Bondarchuk
G. W. Meadows «gw» writes:
I noted in your comparisons of the Litespeed and Climax (both fine gliders) that you mentioned the Combat and how light it is. This may confuse some of your readers (and for good reason), so I figured now is as good a time as any to announce our new glider.
The Combat L is Aeros' latest glider for the flex wing racing market. The "L" is for Light. The glider is the lightest topless wing that we've ever produced and this reduction in weight has made a glider that has tremendously light (while still being predictable) handling.
Our 13 meter size wing (approx 145 square feet) weighs in at only 73 pounds in the "full race" mode. So how did we reduce the weight so much? By going to a 7075 aluminum airframe and carbon fiber ribs.
The 7075 tubing allows us to shave a few pounds off the wing and the carbon ribs reduce the weight by almost another 2 pounds. This glider is officially available now and can be purchased in 3 sizes.
Our website is being updated now with the information about the Combat L and we hope to have it live by the end of this week. www.flyaeros.com.
Currently, Oleg, Bo and Kevin Carter are flying the Combat L in Australia. Oleg and Bo are on the production models and Kevin is flying the 'pre-production' Combat L.
Speaking of Kevin, I would like to welcome him to Team Aeros. I recruited Kevin in October after catching the eye of one of our talent scouts. A tri-athlete, Kevin is familiar with training and competing. He considers the Australia competitions as good training ground for his upcoming North American competition season. He's only been flying hang gliders for a year - and we're very happy to have him on our team.
I'm happy that you're able to get rides on those fine gliders there in Australia. It greatly reduces the strain of traveling to compete in another country, when you don't have the logistical hassles of transporting a glider. Having two major flex wing manufacturers there sure is handy. With this in mind, we'd like to let you know that if you were to decide to attend the Ukrainian Nationals this spring - not to worry - we'll have a brand new Combat L waiting for you. Just as 'home field' has it's advantages in Australia, I'm sure that the Ukrainian Nationals will have Aeros gliders in at least nine of the top ten places. Keep up the good work.
(editor's note: I haven't separately weighed the gliders, so I really don't know the differences in weight between them. Oleg, Kevin, Bo and I are sort of a team here, getting picked up together, and talking on the radio (Oleg doesn't turn on the radio), so I've just been picking up gliders and I noticed that Oleg's seemed lighter than the Climax or the Litespeed. I have no idea if that is true, and I mentioned to readers that they might want to check the respective manufacturer's web site for specifications.
Like G.W. says, it is a great thing to be able to fly gliders in the country that you are going to. I worked out a trade with Airborne and Moyes to rent their gliders in trade for ad space in the Oz Report. As the reader donation/subscriptions and Oz Report ad space is my only income these days, I don't give it away cheaply.
I may take up the offer to fly in the Ukrainian Nationals. We'll look at the calendar. If I can do it before the Worlds in Austria, it might work out. You'll then be seeing some new ads in the Oz Report from Aeros.
4 topics in this article: calendar, carbon fiber, Kevin Carter, Oleg Bondarchuk
Moyes Lightspeed tip wands
Sat, Jan 17 2004, 12:00:04 pm EST
Angelo Crapanzano|carbon fiber|Jon "Jonny" Durand jnr|Kraig Coomber|Mike Barber|Tom Lanning
A pilot writes:
I had ridiculous problems with my tip wands when I got my Litespeed. Thanks to Mike Barber or I'd have bagged the whole thing. Some kind of manufacturing issue with the fiberglass. That ostensibly is ancient history. You'll probably hear from Tom Lanning, though. Same thing happened to him as you except I think his broken wand went through his sail.
I had Angelo Crapanzano, Kraig Coomber, and Jonny look at the tip wand. They agreed that it had broken in a most unusually location - about mid way. It appears as though there was a manufacturing defect and that the sail tension smashed in the wand.
Kraig states that they have never broken a carbon fiber Litespeed tip wand and they have never broken the earlier fiberglass version of the tip wands, except at the junction where the tip wand goes into the leading edge.
The tip wands on the Litespeed have vastly improved over time, and mine was apparently the first of this carbon fiber variety to break. I noticed that the wands remain turn and don't bend after use. Carbon fiber it used to reduce weight at the tip and make the glider more responsive.
I wish manufacturers would be more forth coming about their improvements so that we could know about them and see how things chance over time. Of course, that would require admitting, at least implicitly, that what they did earlier was not all that good.
Kraig gave me his tip wands - although he apparently didn't want me to know that - and I had no problem flying the Moyes Litespeed S 4.5 on the second day. In fact I loved flying it. Jeez, did it even remind me of the Wills Wing U2? Well, not on tow, but maybe in the air.)
6 topics in this article: Angelo Crapanzano, carbon fiber, Jon "Jonny" Durand jnr, Kraig Coomber, Mike Barber, Tom Lanning
Human Powered Flight
Bill Brooke|carbon fiber|John Rankin|Peter Gray
Peter Gray <peter@graynet.net> writes:
Funny, isn't it, how the same ideas crop up over and over (Bill Brooke's pedal-powered harness, Jan 3 photo).
John Rankin writes: "My conclusion was that the harness could extend your glide by a few points but the work involved, the exposure to the elements and the fragility of the prop really ruled it out as something I would want to use commonly." I don't know whether Brooke really expected to get a climb, or even level flight, out of his machine, but he could have determined in advance that it wouldn't do either, without building a prototype.
The minimum rate of energy loss (i.e., power required) with a medium-to-light male pilot on a flex wing (let's say, 250 pounds sinking at 200 feet/minute) is 833 foot-pounds/second, or just over 1.5 horsepower (a rigid wing might require slightly less). A really fit bicycle racer can put out about 0.5 HP for short bursts, but for most people, ¼ HP for any length of time is very strenuous.
That means that in the ideal case, a person could only hope to flatten his or her glide by about one sixth, and one twelfth would be more realistic. Of course, this doesn't count efficiency losses in the propeller and drive train, or the weight and drag penalty from the apparatus.
When thinking about human-powered flight, it's useful to remember the Gossamer Albatross and related craft. Those are always single-purpose, unstable, low-maneuverability, extremely fragile airplanes. Even they are only practically capable of level flight for more than a few minutes, and only with highly athletic pilot/engines, and only deep in ground effect.
Even with their best materials and technology, humans don't have a high enough power to weight ratio for self-propelled flight. Eventually we might have materials that will make it possible, but that will require a much bigger advance than from wood to carbon fiber, or from cotton to Dacron. I've worked on human-powered aircraft, but I'm not holding my breath for any practical applications.
Discuss "Human Powered Flight" at the Oz Report forum link»
4 topics in this article: Bill Brooke, carbon fiber, John Rankin, Peter Gray
Climax in Bright
Tue, Dec 23 2003, 11:00:00 am EST
carbon fiber|PG
carbon fiber|Oliver Barthelmes|PG
carbon fiber|Oliver Barthelmes|PG
Two days before Christmas and after days of rain the sun came out and the winds quieted down as the center of the high pressure moved over the Alpine Shire. It was time to get the Airborne C2 out and take it up Mystic launch for my first flex wing foot launch in over a year.
I had traded Oz Report ad space for the opportunity to fly the Airborne Climax and the Moyes Litespeed while I was here in Australia. I was still unsure whether this was a good idea, given that my recent hours on flex wing gliders was pretty limited. I was wondering if I could get the feeling for them in time for the Hay Open.
The paragliders started appearing around noon over Bright, but I went up to launch (the road is greatly improved) around 2:30 and found the only other hangie around, Oli Barthelmes having set up his Litespeed. There were plenty of "local" paraglider pilots around, but it took foreigners to uphold the hang gliding end of things.
When I opened up the glider bag on the carpeting at the Mystic launch I was a bit taken aback to find this beautiful blue and white Mylar glider with a carbon fiber base tube. Jeez, would I be able to live up to the glider?
The control frame is so big compared to the ATOS that it's hard to get use to. Still with the long hang strap I had to significantly shorten my adjustable strap on my Center of Gravity Carbon Fiber harness.
On launch I was missing my much shorter ATOS control frame. To be comfortable with the height of the control bar above the ground, I had to lift the Climax so that the down tube no longer fit snuggly on my shoulders. No wonder small women pilots have trouble with the standard sized control frames on flex wing gliders.
There was a light wind straight in on launch so the launch itself was uneventful and fortunately there was a big soft thermal right out in front that got me over the top as I made my first turn. Given that I would take a while to get my body to remember how to turn a flex wing glider without constant reminders, this was quite fortunate. It would have been quite difficult to scratch on the hill side in a high performance topless glider.
I kept having to remember to lead with my feet (something you just don't worry about in a rigid wing as you aren't really doing weight shift when flying the ATOS), and coordinating my arm movements with my feet placements. Given my inexperience the glider was much slower to initiate a turn than my ATOS. Also, I wasn't use to pulling in and pushing out to coordinate the turn.
Still, I was climbing up through the apparently less experienced paraglider pilots and getting a feel for the thermals. With the 6 mph west wind up above we drifted back toward the normal lz.
I had noticed before that a flex wing glider feels less twitchy and has a more stable feeling in the air than the ATOS. And while I felt and was less in control of this glider than my ATOS, I didn't worry much about that as long as I was not too close to the paragliders.
If I encountered a thermal with one wing only I found that I would be quickly kicked out of it and had to come around to get into it. I assume that I'll figure out how to control the glider quickly enough to be able to turn directly into the thermal and climb with it. I had no problem doing with when flying the ATOS.
I climbed up a few times over launch then finally headed over to the Porpunka (not on line at the moment so I can't check the spelling) airport and found that while the wind up above was out of the west it was north on the ground. I wanted a nice long straight approach as even after an hour and a half in the air I still wasn't totally comfortable with my command of the glider. Fortunately the Climax almost lands itself (as I remember from when I flew in at the Gulgong Classic last year).
I've got a little over a week to get ready for the first competition in Hay. It looks to me like I'll be able to make the transition.
Discuss the Airborne Climax at the Oz Report forum
2 topics in this article: carbon fiber, PG
Instrument pod⁣s for Garmin 76 and varios »
pods
carbon fiber|instrument pod|Nick Purcell
Nick Purcell «npurcell» writes:
A lot of pilots are now flying with the new GPS from Garmin, the 76S GPS has heaps of features that can really help your flying when you’re out on course. I have developed a new instrument pod (cockpit) that holds the GPS and vario in a light weight, very strong and streamlined pod. The pods are made out of Fiberglas and I make a carbon fiber version as well.
The pods when finished weigh 350 grams or 12 ounces, they are a hollow construction with an aluminum fitting for the bracket to be screwed into, the air speed probe is recessed, making less drag and protecting it from being snapped off. They can be painter in any colour you choose. I now have my web page up and running, you can see the pods at http://homepages.ihug.com.au/~npurcell/ or email me for more information.
Discuss "Instrument pod⁣s for Garmin 76 and varios" at the Oz Report forum link»
3 topics in this article: carbon fiber, instrument pod, Nick Purcell
From flex to rigid
Tue, Sep 23 2003, 4:00:03 am EDT
carbon fiber
Today I had a pilot write to me about his recent
experiences with a Flight Design Exxtacy. He wrote:
We were towing yesterday and a pilot with an Exxtacy offered me a flight on it and kept offering until I accepted. I fly a WW Talon. It was awesome, flying so easy I felt I could fly it all day and not get tired. It also landed so easy in dead calm air. I was then told by a few pilots that an Atos blows away an Exxtacy. Anyway I now think I might want to pursue rigids and welcome any advice, etc.
I provided the pilot with some links to more information.
Personally, I enjoy flying both rigid and flex wing gliders, but it is abundantly clear that the addition of aerodynamic surfaces substantially reduces the effort required to fly a hang glider. Aerodynamic surfaces also allow the designer to put dihedral into the winds, thereby substantially improving the stability of the glider which is especially helpful during towing and long glides. Towing is much easier with a glider with dihedral.
High performance flex wings have to have anhedral in their wings in order to somewhat overcome their “stiffness” in the initiation of a turn.
It is unfortunately the case that flex wing designs are artificially inhibited by the glider classifications from adopting aerodynamic control surfaces. If they were to adopt this “innovation” it would require that they compete (in competitions) against the more expensive carbon fiber rigid wings. They might have an advantage in the marketplace though.
The use of aerodynamic surfaces would also allow the flex wing designer to make those rigid flex wings even stiffer than they are now. They can also pull out all the variable geometry mechanism that they use to overcome this “stiffness” problem. Whether a flap for slowing down and decreasing the length of the landing would be worth the cost is unclear to me. Just use a drogue chute (or get your harness open and your legs out).
You’d have to figure out how to pack the spoilers
in a thinner package. Perhaps they could be easily detachable and lay across the
width of the rolled up glider. They can also be quite thin as Felix has shown
with his aluminum spoilers on the AIR ATOS-C.
Discuss rigid vs. flex at OzReport.com/forum/phpBB2
1 topic in this article: carbon fiber
Aeros Combat 2 – the unique aspects thereof »
Thu, Aug 28 2003, 5:00:03 pm EDT
Aeros Combat 2|carbon fiber|Paris Williams
Aeros Combat|Aeros Combat 2|carbon fiber|Paris Williams
Aeros Combat|Aeros Combat 2|carbon fiber|Paris Williams
G. W. Meadows «gw»
writes:
The Combat 2 is a glider that utilizes fully all the technology available to us currently. Aeros uses tests performed in a full scale wind tunnel to maximize the performance of this wing. Of course, performance is one thing handling is a totally different beast. If you can't precisely control that performance, then it's no good to you in competition. The competition results of the Combat 2 speak toward the performance of this wing. It's the most winning glider in U.S. meets for this year!!
Through 'multi-stage' flex control along the leading edge, Aeros has been able to make a glider that is stiff enough to hold the loads of high speed while flexing where necessary to create incredible handling. Paris Williams (current U.S. National Champion) was so impressed by this handling that he joined the Aeros team just three days after his first flight on the current production Combat 2. This same multi-stage flex control is part of the reason that the Combat 2 has the great landing characteristics that weren't present in our Stealth series.
The Combat 2 (as well as all the Aeros flex wings - including the Aeros trike wings) utilizes 2024 T-6 aircraft quality aluminum for its leading edge member. This alloy gives the desired flex characteristic and has the welcomed side effect of not breaking explosively in the event of a very bad landing/crash. For anyone who has ever broken a 7075 leading edge and had it explode through the sail of their glider, they know all too well the extra costs of this type of mishap. Of course, no one ever expects to break a leading edge when they are buying a hang glider, but reality is that accidents do happen.
Another great money saver is the 3 piece leading edge construction of the Combat 2. Seldom does anyone damage 2 sections of a 3 piece leading edge in one mishap. Why buy 12 ft of leading edge replacement when you only need 7 ft? Because of the 3 piece leading edge design and the 2 piece keel, all parts of the Combat 2 (except the carbon crossbar) can be shipped via UPS. This also is a great money saver!! Parts cost a fortune to ship by truck, not to mention the fact that truck can’t deliver to you overnight across the country. This convenient part replacement is not by chance. The Aeros gliders are well thought out down to the cost of replacing parts.
The Combat 2 features the 'microdrag' control frame. It has the same downtube airfoil designed and optimized by WW and the Aeros control frame features the most comfortable carbon basetube in the business. Many pilots of our competitor's gliders have purchased this carbon fiber basetube from us to install on their gliders because of its extreme comfort and streamlined efficiency.
Probably the most unique feature of the Combat 2 is the fact that the same glider the top guys fly is the same glider that the customer gets. This is not that case across the board on all the comp wings currently flying. We are very proud of this fact.
When you put it all together, we feel that we have the highest performance for the dollar. We also feel that anyone who does a little research will have to agree.
Discuss Combat 2 at OzReport.com/forum/phpBB2
3 topics in this article: Aeros Combat 2, carbon fiber, Paris Williams
US glider pricing
Thu, Aug 21 2003, 4:00:02 pm EDT
carbon fiber|Lookout Mountain|Rich Burton|Wills Wing
Aeros Combat|carbon fiber|Lookout Mountain|Rich Burton|Wills Wing
Aeros Combat|carbon fiber|Lookout Mountain|Rich Burton|Wills Wing
It is always difficult to get a real idea of the cost of a particular glider in a particular configuration and then be able to compare prices across manufacturers because each of the manufacturers does it their own way. My price listing from two days ago was meant to include most (but not necessarily all) of the options that would be used in a competition glider. Some I didn’t included because not every manufacturer offered them, or I couldn’t find a listing for what each manufacturer included in their competition package.
Some had Mylar sails, some didn’t. All had aero control frames, some with carbon fiber base tubes and downtubes, some with aluminum. I didn’t include carbon fiber inserts for the leading edges, nor carbon fiber outboard leading edges for the Moyes Litespeed S, as other manufacturers don’t include these ($495).
You can look on the same web sites I did (links included in the article) to find out as much as I know (and maybe more), about pricing.
Rich Burton «indasky»
writes:
Suggested retail for an MR with the Mylar sail and the
MR frame would be $7812.86 in the US.
The Euro price for the same glider is 7275 euros. Even
at the current exchange of 112.00 which is much better then it has been for many
months, the 7275 euros is over $8000.00, and that doesn't take shipping into
account.
Sales in the US have been slow, but there are a few pilots out there that have put the quality of the product above the cost.
Jon at Lookout Mountain «fly» writes:
The standard retail price for a Climax 2 is $5495. That's a Mylar sail with standard frame.
As I recall the standard control frame is aluminum with aero base tube. So it looks like we have two gliders at the higher end in the US – the Icaro200 Laminar MR, and the Moyes Litespeed S, and three gliders at the lower end, cost wise – The Wills Wing Talon, the Airborne Climax, and the Aeros Combat 2.
Price is a function of supply and demand. If a
manufacturer can increase the demand for his product by perhaps making it look
rally good in competitions, than the price can go up. The glider manufacturers
who have comparable performing gliders that aren’t being flown by a lot of the
world’s best hang glider pilots might be experiencing less demand, and
therefore must price their gliders so as to encourage what demand there is.
It’s a cruel world.
Discuss topless gliders at OzReport.com/forum/phpBB2
4 topics in this article: carbon fiber, Lookout Mountain, Rich Burton, Wills Wing
Tsunami »
Alessandro "Alex" Ploner|Alex Ploner|carbon fiber|competition|control frame|Flytec Championships 2003|landing
Was it the cool, sharp control frame of the Tsunami that gave it that little bit extra on the high speed glide? Compare the AIR ATOS-C control frame with the Tsunami and you might come away thinking that that might be the ticket.
The AIR ATOS–C down tubes and base tube are quite a bit thicker than what you’ll find on the Moyes Zoom frame, the new Icaro 2000 MR control frame, or the special carbon fiber frame on the Tsunami. Felix adds turbulators to the front edge of the control frame to keep the air stream attached. This is to offset the thickness of the airfoil section.
Why the thicker section – so you don’t get cut up so bad when you make a mistake on landing. Notice that a few folks have had this problem of late. Felix is thinking about the average ATOS-C pilot, not just the one or two top competition pilots.
Is the trade off worth it? Well, Christian and then Alex Ploner won the Flytec Championship and the Wallaby Open respectively.
Discuss "Tsunami" at the Oz Report forum link»
7 topics in this article: Alessandro "Alex" Ploner, Alex Ploner, carbon fiber, competition, control frame, Flytec Championships 2003, landing
Tighten them nuts – Moyes Litespeed 4 with Zoom frame
carbon fiber|competition|control frame|John Dullahan|Moyes Litespeed|nylon|site
John Dullahan <johndullahan@comcast.net> writes:
About 14 months ago I bought a year-old Litespeed 4 with about 100 hours from an active competition pilot. Since then, I put about 30 hours on the glider and have been very happy with its performance and handling. It came with a competition control frame (special downtubes and carbon fiber fared basetube).
Last Sunday, while assembling the glider at the Pulpit, a site near McConnellsburg, PA, the right downtube fell off the point of attachment to the keel. The very small nut on the bolt securing the downtube to the U-shaped housing (attached to the heart bold) had come off completely, allowing the bolt to fall out and the downtube to become detached from the keel. The nut securing the bolt on the other downtube was loose as well, but was still on the bolt.
I found the loose bolt and reattached the nut. (On the right downtube, a very thin screwdriver must be used to get past the VG cord and reach the deeply-recessed bolt. The bolt is tightened into the nut, which will not turn as it secured in a small area). The left side also needs a thin screwdriver however it's easier to reach due to the absence of the VG cord. Even when fully tightened, the bolts do not extend beyond the nylon locknuts (the bolt ends are level with the nylon; showing no threads at all).
Since these bolts are critical points and probably loosened over an extended period, I would have detected them had I been conducting complete and through pre-flight checks as called for in the Litespeed manual. Therefore my own negligence led to the unsettling sight of a downtube falling from the glider during assembly. The nuts, however, are very small and may be overlooked by pilots using similar control frames on Litespeed 4s (I don't know if the Litespeed 5 competition control frames have similar bolts).
If tightening them does not result in about three threads showing beyond the nylon, I strongly recommend removing them and using Locktite to add an additional measure of security, then inspecting them carefully during preflight checks.
Discuss preflights at OzReport.com/forum/phpBB2
Discuss "Tighten them nuts – Moyes Litespeed 4 with Zoom frame" at the Oz Report forum link»
7 topics in this article: carbon fiber, competition, control frame, John Dullahan, Moyes Litespeed, nylon, site
Mark’s antenna
antenna|carbon fiber|Mark Poustinchian|radio
Mark Poustinchian <mpousti2000@earthlink.net> has come up with an antenna that he claims is superior to my little dipole. I haven’t had a chance to make a long range test yet. He takes a hot rod and replaces the telescoping antenna with a glider wire.
He’s put a SWR meter between the radio and the antenna and tested the signal strength as he moves the carbon fiber flaps up and down. The dipole antenna in the hang strap is adversely affected by the flaps. This antenna which hangs down from your pod, is not affected.
The base of the antenna is screwed into a BNC female adapter and that is connected to a 6’ coaxial cable that runs to your radio. I’m hoping that Mark will put up a web page with his instructions on how to make the antenna.
If you let it dangle behind you, it should make about a 45° angle with the ground.
Discuss "Mark’s antenna" at the Oz Report forum link»
4 topics in this article: antenna, carbon fiber, Mark Poustinchian, radio
Will fly for subscriptions »
Sun, Mar 2 2003, 4:00:00 pm EST
calendar|carbon fiber|David Hempy|Dennis Cavagnaro|Flytec 4030|PG|Quest Air|record|Richard Heckman|Tove Heaney|USHGA|Wallaby Ranch|weather|World Record Encampment
Oz Report reader who have helped out on Sunday: Wayne Ripley.So how am I doing asking pilots to volunteer to pay for their subscription to the Oz Report? Well, pretty good. I’ve received money or pledges from 165 pilots. The total pledged, sent electronically or handed to me so far is $2385. I’m stoked.
The total number of regular Oz Report readers is about 2,400. About 3,000 were reading during the peak of the Australian competitions. 165/2,400 = 6.9% of the Oz report readers are voluntarily supporting the Oz Report. This is actually a pretty high number. I just bet that public radio stations would be very happy to get 7% of their regular listeners to support the radio station.
Now Oz Report readers have been very generous, and given much more than the asked for $10 donation/subscription. Many pilots who’ve given extra money have done so with the thought that “Hey, Davis, isn’t it about time? I’ve been reading the Oz Report for years now, and here is three year’s worth of subscriptions,” so I can’t expect such generosity when I ask for renewals next year. None the less, just assuming that the money was coming in $10 donations from 238 pilots, then that is 10% of the Oz Report readers supporting the Oz Report. Very cool.
You can see how to send in $10 for a yearly subscription to the Oz Report below.
The Oz Report is going to keep track of hang gliding (and a few paragliding) records. Not just the World Records, like the ones set at the World Record Encampment, but also national, regional, and state records.
Also, single surface and kingposted records. And women’s records.
We probably won’t have all the possible records, but enough to encourage hang glider pilots to go for it.
If we haven’t got a record up that should be there (and I’m sure we’ve missed plenty) you might want to make fun of us by sending in the record. Thanks.
The east coast flex wing record is 218 miles. Set last summer in Leland, Illinois (see above). The furthest a flex wing glider pilot has gone in Florida is 203 miles. What about trying to set the new east coast record on a flex wing glider?
Yesterday, Bo was testing his Aeros target with carbon fiber down tubes. He’s going for the single surface record, and he’s not alone. I’m trying and I’m not alone. It’s the $1,000 and the focus of going for the $1,000. It’s also the fact that you only have to fly 100 miles.
But, who’s going to try to break the east coast flex wing record? Who’s going to try to fly 250 miles in a flex wing hang glider on the east coast?
Let’s look at the prize situation:
$1000 – fly a single surface hang glider 100 miles from Wallaby Ranch.
$1,001 – fly a single surface hang glider 100 miles from Quest Air.
Flytec 4030Race ($900) – fly any hang glider 250 miles from Quest Air (must fly with Flytec vario)
$2,000 - fly any hang glider 300 miles from Wallaby Ranch
$2,001 - fly any hang glider 300 miles from Quest Air (reduced to $1,001 if flown on non Flytec vario)
Do we need a little more encouragement in the 250 mile range? For flex wing hang gliders?
Meet organizers do not provide enough pre selected waypoints for competitions. We have gone over to GPS contests during the last few years, but meet organizers haven’t yet caught onto the fact that they’ve got to get a whole bunch of waypoints in their waypoint list that can be downloaded at the start of the contest.
The only waypoints that really need to be associated with ground features are landing/goal areas, and these should be especially designated waypoints (using a symbol). Waypoints can be associated with ground features, and it is pilot friendly to do so, but they don’t need to be super accurate. As long as they are close, the pilots can use what they see while flying to match what their GPS is telling them.
Also, it would be great if the goal waypoints had six character names, the last three of which were the goal altitude in hundreds of feet. For example, GLF015, would be a goal field with an altitude of 1,500 feet. This would be a big convenience to pilots flying with Brauninger IQ/Comp varios.
The meet directors should put out waypoint lists with a couple of hundred waypoints. In this way the task committee won’t be choosing new waypoints at the last minute, the pilots won’t have to enter the new waypoints at the last minute (perhaps in a format they hate), and the meet organizers won’t be miscalculating where the goal fields are and sending pilots to goals in the middle of nowhere.
Tove had well over a hundred waypoints at the Australian Open and this is a very good start and the best showing so far. The problem was that she had almost all of them within too short a distance of the tow paddock. She needed another hundred spread out for the big days, so that we didn’t have to do so many zig zags.
Tove directing the Australian Open
As you get away from the tow field the waypoints can be further apart, less dense, than near the tow field, so you don’t need necessarily as many. Getting a couple of hundred waypoints and a good map that prints them out for the task committee really helps making decisions.
If the meet organizers do this in advance then it really cuts down on the work that pilots have to do at the last minute, makes for better decision making on the part of the task committee, and much reduces the panic that pilots as they are pressed for time right after the task is called.
How is this best done?
Meet organizers can use MapSource from Garmin or SeeYou to create a large list of waypoints just by pointing and clicking on the built in maps. They can read their current list of waypoints with G7ToWin, and convert them to PCX files for importation in MapSource or CUP files to be read by SeeYou. They can change the symbols in these programs to mark goals. Let’s use symbols to designate goals, and not special names (except for last three digits).
They can then add to their waypoints lists using the maps in these two programs (available around the world). When they are done they can download directly from MapSource into GPSes. Or, the can download with G7toWin.
I’m sure the other programs will also allow for the easy creation of waypoint files from built in maps or easily available maps (although Street Atlas doesn’t version 8). Goal coordinates can in some cases be taken from maps, but in most cases it is best to take coordinates from actual visits to the goal sites, if possible.
I really strongly urge meet organizers to see it as an important part of their meet organizing efforts to come up with a couple of hundred turnpoints and enough goals to help make their meets run more smoothly and with a higher degree of validity.
You’ll find a couple of web sites for keeping track of the Florida weather: www.davisstraub.com/Glide/wallabyweather.htm and www.davisstraub.com/Glide/questerairweather.htm
There is a bunch of overlap between these two sites. Get ready for your next trip south or see what is going on before you get here for the upcoming competition season.
David Hempy «dhempy» writes:
Don't overlook the Garmin eTrex series. Despite that they are some of the least expensive GPS units available ($99 at Amazon for the base model), they really pack a punch. They offer a 12 channel parallel receiver, 20 hours life on 2 AA's, 1500 track points on the base model and 2000-3000 on the other models, serial port, etc. Different eTrex models have other features, including map databases, barometric altimeter, etc. We allowed a variety of GPS at the 2002 US National Microlight Championships, and the eTrex were the most successful in every measure. I have personally found them to track better and more reliably than other (low-end consumer) GPS units I've flown with.
For more details, click on the "Comparison Chart" link on this page: http://www.garmin.com/products/etrex/
(editor’s note: Well, not quite. The problem is that the cheap models don’t allow you to set the tracklog record time interval, but only have automatic mode. Fine if you are going straight like on an ultralight that doesn’t matter, but if you are making a bunch of turns, the GPS uses up all its track log points before the flight is over.
David writes:
Here is a log of a flight I made this month with the tracklog increment set to "auto" on the yellow (cheapest model) eTrex. (I also have the green "Venture" model, but I actually prefer the human interface of the yellow one)
http://www.davidandjanine.com/ul/straub
In the two detail images, you'll notice the trackpoints are spaced every about every ten seconds (about 200 m) flying straight and level. Then, during a 1 minute 360, the interval drops to around 3 seconds a pop (50 m or so). After powering up the GPS, and leaving it on the hood of the car before the flight, it took one trackpoint in 16 minutes. The two points were 3.02 m apart. That would have consumed about 1000 trackpoints at a 1 second interval, or 200 trackpoints at a 5 second interval.
In the "whole_log" map, you can make out the trackpoints joining the alternating red and green segments of the track. (Sorry for the quality...I compressed the images pretty tight.) The 360 in the detail is at center of the semicircular course. (Ever try to fly a 15km-radius circle? Not easy!)
You'll see in the "detail_data" file that it took 569 trackpoints for a 97 km trip. That's about 1/3 of the little eTrex's capacity, and 1/6 of some models' 3000 trackpoint capacity.
You can see more about this flight, including the .loc file that has the raw data, here: http://www.davidandjanine.com/ul/tasks/2002-02-01/
I just checked, and I had them reversed. You cannot set the tracklog interval on the yellow unit. You can on the green Venture model. (I was mistaken when I called it the Vista...It is the Venture).
As for the distance interval, the minimum setting is 0.01 units, where the units are miles or kilometers, depending on how you've got the default display set up. So, if you're enlightened enough to use the metric system, you can set it to a 10 meter increment. I have not tested it in this configuration.
We generally will make three turns on a triangle course (Well, six or seven including the pattern.) so Auto is pretty ideal. I didn't consider that you guys spend much of your time thermalling. I can see know why Auto works so well for us, and not so well for you.
Perhaps the Venture would be a better fit then. With 2048 track points, and the ability to set the interval to any number of seconds, you could get 5.5 hours out of a 10 second interval. I think I paid $169 at WalMart in December 2001 for it. (MSRP $194) (http://www.gpsnow.com/gmetvt.htm)
I also notice the top-of-the-line Vista (MSRP $375) has glide ratio and glide ratio required to make goal functions. I don't know too much about that, but it sounds like it might be right up your alley.
Richard Heckman «hekdic» writes:
I've been on glucosamine 1500 mg /chondroitin 1200 mg for about 4 years and my orthopod says that the Hopkins guru that just invented the latest knee prothesis has been on it for about that long and if it's good enough for him, it's good enough for his patients. Long term studies are still under way but short term European studies look good.
I had the last two fingers of each hand going numb back in 1990. I started isometric exercises to strengthen my neck and stopped sleeping on a pillow and substituted a 4" roll of foam under the back of my neck. 4" foam is about the right height when you roll over and it seems to cradle my neck just about right. It took about 6 weeks but my numbness went away. Since then, I've had an occasional feeling of numbness if I've been in some weird position but that's it.
It might be interesting to find out if there is a larger number of HG pilots with neck problems than the general public. Prone flying might be making us more susceptible.
Dennis Cavagnaro «dcavagnaro» writes to Jayne, executive director of the USHGA:
I would like to respond to your letter and explain why the first issue of the real combine magazine has unleashed such a strong protest.
You are right that there was a positive higher numbered second vote after the first one was determined to not be representative. The fist vote didn't have the benefit of your public relations campaign, all the USHGA resources and a very comprehensive "sample magazine to influence it. It was a plainly ask question and a small group responded negatively.
You have a agenda that I thinks stretches the authority of being the organizations executive director. It appears you see it as your role to shape the perception of Hang Gliding and Paragliding and in doing that a single voice would be helpful. Having a single magazine and not allowing the two different sports some autonomy will help you meet those agenda's needs.
We have gone from a situation where each sport, hang gliding and paragliding, had their own publication, their own photographs and their own set of feature articles (February issue in Hang Gliding alone had six) to a magazine that is less the 25% bigger with larger type and only 4 features to cover both sports. We have gone from a staff of 2-3 producing two magazines to a staff of 4 hired professionals producing fewer results.
The latest issue is nothing like your public relations "sample" that was distributed before the second vote. You promised and displayed double the magazine and double the content with that sample. In reality you only doubled the staff.
I wonder how the paraglider pilots feel about one featured article and I note we hang gliding pilots haven't experience a one-sided Paragliding issue yet with paragliders only on the cover. I wonder what our reaction will be then.
I ask that you consider either another vote now that everyone is paying attention or a non-magazine membership with a reduced cost ($15-$20) so we can go an support our publication of choice.
That would be a much fairer way of settling this and dealing with all of your constituents.
(editor’s note: I am waiting for one comment from a specific paraglider pilot, then I’ll leave this to the hang gliding mailing list for further discussion (or you can go to the new Oz Report hang gliding discussion group, see below).
I would love to see a membership choice, such as a check box:
[ ] Send me HG/PG Magazine
[ ] Send the $15 to the Oz Report.
Yah, that seems like a good vote.)
Cheaters!
Wed, Jan 15 2003, 6:00:05 pm EST
carbon fiber|Florida|Kari Castle|Mark Poustinchian|Mike Degtoff|Wills Wing|Worlds
Mark Poustinchian «mpousti2000»
writes:
When my very old ATOS was upgraded to ATOS B last
spring in Florida, I noticed that it started to glide much better with the new
thin spoilers and carbon fiber tips. I still had the front wires however the
glider was doing fine. I was flying with one of the comp pilots who is a fine
pilot and had just picked up his new ATOS-C and flying it. I saw him the next
day and he said that he had complained to Felix the night before that my old
ATOS was out climbing and out gliding his new ATOS-C. To be honest, I was very
surprised myself when I noticed the same thing.
I had another opportunity to fly with another ATOS C pilot in Big Spring comp in Texas. This other pilot on the first day of the comp had the low drag salad bowl helmet, super low drag carbon fiber harness, super micro drag Wills Wing control frame and a nice ATOS C. Remember that day Davis? It was you.
(editor’s note: What I remember about the 2002 US Open was hanging on to my ATOS-C for dear life and cursing that fact that I had ever given away my tail.)
We were climbing in a thermal with Kari Castle and when
we topped out the thermal about 6000’ agl, all of us went on a long glide. I
was at top and you were very close and maybe about 50’ below. I was flying my
old ATOS with standard down tubes, an old and big harness with lots of drag, my
big and fat base bar with the built in glove compartment which was holding my
instruments and my lunch box at the same time. We had a long glide very close to
each other and at the end about 5 miles away I was about ½ mile in front and a
few hundred feet above. I was shocked and amazed at what my glider was doing. I
realized that I wasn’t imagining things and my old ATOS was out gliding the
ATOS C gliders. I was flying very fast and every day that I made goal, I had the
fastest time.
(editor’s note: OzReport.com/Ozv6n151.htm.
Here is my statement at the time: “Without the V-tail, I am a nervous wreck
for the first hour in the air. The ATOS is jumping all other the place (as far
as I’m concerned), and I’m just happy to have the football receiver gloves.
I try to relax.
“It is great to be competing and racing with Kari and Mark as we lead the 2 PM group to the first turnpoint. The sink is big and the lift is 700 fpm in small cores. The cu’s are every where, but only half or so work.”)
I always took a later start time and tried to catch
everyone and pass them. Some days I would take the last clock which was ½ hour
after the first start time and it was fun to pass pilots on the way. I had some
opportunity to glide with Mike Degtoff who was flying the Stalker and liked to
take the first start time. For some reason, on a few days that we both made goal
I was catching up to him somewhere on the second leg and after that I couldn’t
shake him off. We flew together for a while until our instruments were showing
that we got goal made and we go on glide from many miles away. At high speeds he
was leaving me behind and I didn’t like it at all.
On the last day, again I was able to catch Mike and
Rich Barton whom had taken the first start time. We were together by the second
turn point and I started to do the pulling again. It was very interesting to fly
with them that day. We were in the last powerful thermal which I had found and
going up very fast. We were about 12 miles from goal. Mike left first and I
immediately followed trying to keep up and tried to at least beat Rich to goal.
Rich was a few hundred feet below us and was flying the Stratos that Christian
from Italy flew in Chelan and had won the Worlds Championship with. After a
short while Mike was able to pull away from me and I was trying hard to get to
goal next. I was flying fast with lots of bar pressure and was having a bumpy
ride.
After a few minutes, I saw Rich a little higher than me
to my left and passing me at a very high speed. “What the $%@#, how is he
going so fast? I asked myself. Here I was getting beat by the rough air and
dealing with it and here is this guy passing me like I am glued to the ground. I
knew right away that the glider that he was flying was a beefed up and modified
glider. There was no way that I could keep up, go that fast and have that kind
of glide. Here I was beating the ATOS C gliders and here was this ATOS’s twin
glider going so much better. If you want to beat me and feel good about it beat
me fair and square, not on a beefed up glider that is gliding so much better
than mine. I finished with the fastest time at goal, however, I was the third
pilot in that day. I was happy that after a late start, I was able to catch
these super duper gliders on the way to goal, however I was not happy when they
were beating me to goal on the last glide. I am just thinking what the results
would have been like if I was flying these faster gliders.
(editor’s note: What does Mark mean by beefed up
here? What would make the Stratos go faster? How was it modified? I don’t
think Rich had any ballast.)
Anyway, I hope you see what I am trying to say here.
The ATOS C that you and lots of my friends are flying, aren’t the same as the
ATOS C gliders that Alex or Tony are flying. They have put more safety features
into ATOS C to make them safer. However they have sacrificed a little
performance to achieve this. These pilots flying these modified gliders are top
pilots, but give me a break here. If you want to beat me, I like to see if you
like to exchange gliders with me first and then try to beat me.
I am guessing that these gliders have extra carbon
fiber on the leading edges for super stiffness at high speeds, lower twist,
lower sweep and maybe even lower dihedral. All of these can and will improve
gliders performance in a big way. You maybe able to lower the sweep on your
glider, however lowering you twist and dihedral are factory jobs.
All that said, here is what the problem is. It seems as
we want to have the cake and eat it too. On one side we cry for safer gliders
and ask the manufacturers to make them safer and at the same time on the other
side, we are trying to beat the super duper modified gliders. I bet if you are
willing to sacrifice your safety and be willing to fly these supper gliders
which maybe a little unstable in the air, they may make you one too. Is that
what you want? I wish there was a way to control all this in a comp and all the
gliders from the same manufacture were the same.
My message to these pilots who beat everyone on these
hot ships is; “you are not as good as you think you are and you know it, if
you were, then you fly the same glider that others are flying, then you would
get much more respect from me and others. Stop cheating your way to the top.
7 topics in this article: carbon fiber, Florida, Kari Castle, Mark Poustinchian, Mike Degtoff, Wills Wing, Worlds
Rack pads for ATOS
Wed, Jan 15 2003, 6:00:03 pm EST
carbon fiber
If you want to keep your ATOS free of damage from your racks, then you’ll need a set of carbon fiber rack pads such as these:
You can get them from AIR (www.a-i-r.de) or your local ATOS dealer. These are the latest version that are a bit smaller than the previous ones. I don’t have a price on them yet.
1 topic in this article: carbon fiber
Kari, try carbon fiber
carbon fiber|Kari Castle|Mark Clark
Mark Clark «mclark» writes:
Has Kari ever flown in a Carbon CG?
Unless you are suggesting that harness manufacturers design a back frame in the shape of an Hour Glass, I think that Jay will tell you that comfort is more a matter of the frame support than the cut of your harness cloth.
The Carbon CG does not have cloth pulling off a small frame. It is the cloth pulling from this small frame that produces the added pressures on parts of our body more than cutting the cloth to fit a woman's or man's figure. (Jay made the CG 1000 & CG 2000 for 13 years. Both are precursors to the Rotor and the like.)
Unlike cloth harness with a 27 inch (approximate) back support frame, the Carbon CG acts like one big +65 inch full body frame supporting you from your shoulders to your ten toes. This has eliminated most of the uncomfortable pressure points. For an added bonus, your chest floats on an adjustable air cushion.
Discuss "Kari, try carbon fiber" at the Oz Report forum link»
3 topics in this article: carbon fiber, Kari Castle, Mark Clark
Vacuum bag it
carbon fiber
Want to build a fiberglass, carbon fiber, Kevlar, or carbon fiber/Kevlar part (or perhaps a helmet)? You can set yourself with an inexpensive vacuum bagging system with an old refrigerator pump, a garbage sack, and a little tape.
Here in Australia you can go to your friendly neighborhood refrigerator/appliance store and get some help with an old pump from a worn out frig. Try that in 90% of the US. Market efficiencies and the desire for the big bucks have driven such business out of business there.
Anyway, you can use carnauba wax (car wax) to cover the inside of the mold so that you can pull the part off the mold. There is a great fiberglass shop down the street here in Ballina, with everything that you need (well it has fiberglass and not carbon fiber or Kevlar).
Don’t let the pump overheat. The bag should have some small holes in it which may form naturally as it tightens around the mold. If the pump gets too hot, just turn it off.
You can learn more about the technology by looking at RC model builders’ web sites.
Discuss "Vacuum bag it" at the Oz Report forum link»
1 topic in this article: carbon fiber
New Aeros Harness
calendar|carbon fiber|Florida|Quest Air|Wallaby Ranch|Worlds
G. W. Meadows «gw» writes:
Aeros announces the release of its newest racing harness for hang gliding – the Viper. Being one of the world’s largest suppliers of hang gliding harnesses, Aeros had fallen behind in the past couple of years with new innovations.
In 1997, Aeros introduced the first production ‘internal parachute’ hang gliding harness to the worldwide market. The “Racer” was quickly emulated by nearly all harness makers and many of the features of that harness are still in use in today’s cutting edge harnesses offered by the most successful harness makers in the world.
Adding to Aeros current offerings of harnesses (the Myth, Racer, Extreme and Cross Country), the Viper is without a doubt the lowest drag harness made to date by the Aeros harness factory. This was not without much research and many trial versions. The Aeros design team was able to utilize the Antonov wind tunnel for in-depth study and application of various harness drag reduction ideas. The result is a complete makeover of the Aeros racing harness design. The VIP employs several new features for Aeros harnesses and one particular new feature for the harness market.
Carbon Back frame: This is Aeros’ first harness utilizing a torso-contoured carbon fiber back frame. This 33cm wide, gently curving back support system allows the harness to fit as close as possible to the pilot while still allowing ‘non-binding’ support. Pilots who have tried this back frame system have raved about its comfort. Depending on the pilot’s height, the back frame will be between 80cm -105cm long.
Variable Pitch System: After much R&D on the best system for varying the pitch angle of the harness, Aeros has decided to go with the ‘shoulder line’ system, while utilizing an internal activation of the effective line length. Aeros evaluated many of the other pitch systems on the market and found drawbacks with many – including the tendency of the pitch system to slip or fail to deactivate when necessary.
Employing a brand new (and highly reliable) plate and lever system, know as the PPS (the Positive Pitch System) – more reliable than those used in previous models, the Viper pilot is able to easily adjust the pitch of the harness with his/her butt – without taking their hands of the basetube.
Matrix Outer Skin: The Viper has a Matrix cloth outer skin for drag reduction. This cloth proved in the wind tunnel to be the most ‘slippery’ available to the consumer market. Now for the newest feature on the harness market- with the Viper, the customer will be able to replace the entire outer matrix cloth covering at anytime with a new one. Utilizing a clever system of Velcro attachment, this Viper will be able to ‘shed its skin’ and take on a new one. The customer is basically able to create a new harness for a fraction of the cost.
Dual Parachutes: The customer has the option (included in the price) of choosing dual chute containers (one on each side of the harness) or a single parachute container with a 4 pocket container on the opposite side.
Storage: The Viper allows for a surprising amount of storage for such a sleek racing harness. It has storage in the tail section, as well as a wide storage section next to the back plate. An additional internal pocket for pads and such rounds out the storage offerings for the Viper.
Parachute Bridle Attachment Options: The Viper Pilot will have the option of internal bridle attachment (at the shoulders) or the traditional carabineer attachment. The harness comes standard with both methods in place.
As you can see, Aeros has completely ‘reworked’ its harness design and has come up with a winner. See your local Aeros dealer or contact Aeros for more information.
Discuss "New Aeros Harness" at the Oz Report forum link»
6 topics in this article: calendar, carbon fiber, Florida, Quest Air, Wallaby Ranch, Worlds
Triathlon athlete at almost 80 years of age – Bill Bell »
Thu, Oct 10 2002, 2:00:02 pm EDT
carbon fiber|Triathlon athlete at almost 80 years of age
When I get to Cathedral City in the fall I’m on tap to provide computer support services to all my father in law’s friends. One of them called me up with a plaintive wail that nothing was working, and he couldn’t get on line anymore.
Turns out that he had the Bugbear virus even though he had Norton Anti-Virus installed. It was just the case that he didn’t know that he should be live updating it regularly and that he didn’t have any compunction about not holding back on clicking attachments. Funny part was that this disabled his e-mail (if Norton Anti-Virus was still installed) so I wondered how the Bugbear virus would replicate itself through Outlook Express. Of course, Bugbear also disables Norton Anti-Virus, although it doesn’t uninstall it.
Bill is an interesting character and devotes a large part of his time and effort to being a competitive tri-athlete. He enters enough triathlons each year to be able to qualify in his age group (75 – 79) for the Ironman in Hawaii. He is about to head for Hawaii in a few days. This is like getting to the worlds in hang gliding (and not from some little punk country, either).
http://www.insidetri.com/news/fea/173.0.html
When he comes back he will be running a special triathlon which will be celebrating his 80 birthday. Apparently a lot of folks from around the world are coming to Palm Desert for the meet. 80 laps of the pool, etc.
I was standing around in his garage with him and his four bicycles one of which he was working on getting it ready for the Ironman. He had to glue on some tires. The bicycles were carbon fiber affairs, much different than anything I had seen in any bike shops.
Last year Bill had to stop during the bicycling part of the Ironman race as his heart was racing too quickly. He knew before hand that this might be a problem, but due to technical problems with hospital equipment he was unable to have the minor surgery that would correct this problem in time for the Ironman last year. He has since had the surgery and how the heart runs a little too slow for him.
Bill shows that with the right spirit and good health, you can compete at the highest level in the most strenuous of sports. Of course, the triathlon is a much more strenuous sport than cross country hang gliding, but I would love to be beating those hot new young pilots across the finish line 25 years from now in the Australian Open and the Flytec Championship.
http://vnews.ironmanlive.com/vnews//1022100850/?keywords=Bill:Bell
http://www.google.com/search?sourceid=navclient&ie=UTF-8&oe=UTF-8&q=%22Bill+Bell%22+Ironman
2 topics in this article: carbon fiber, Triathlon athlete at almost 80 years of age
Small carbon fiber repairs
Wed, Oct 9 2002, 2:00:03 pm EDT
carbon fiber|Ian Duncan
Ian Duncan «compositecreations» (who builds the carbon fiber cross tubes/spar for the Moyes Lightspeed) writes:
I would suggest that an overlap of 1 1/4" (32mm) is more appropriate when using carbon and epoxy. This means 30mm past the damage area in all directions.
I believe it is best to instruct novices in the correct procedure as one day they may attempt to repair a structural part of the wing and only remember what they read in the Oz Report in the past. A 1/2" overlap is by no means sufficient in a high load area!
(editor’s note: The last article was in reference is very very small repair areas. Larger ones would benefit from Ian’s advise here.)
2 topics in this article: carbon fiber, Ian Duncan
Small carbon fiber repairs
Tue, Oct 8 2002, 10:00:03 am EDT
carbon fiber|Steve Daleo
Steve Daleo «daleoenterprises» writes:
It's important to keep all the fibers in the skin aligned and unbroken to maintain the full integrity of the wing and the only way to do that is to patch the small holes with some carbon cloth and resin. It doesn't have to be a messy involved process.
Simply prepare the area to be patched by sanding a small circular area about a half inch outside the crack (I'm assuming these are tiny rock dings). Then, lay a piece of carbon cloth on a heavy piece of clear plastic and impregnate it with resin.
Cut out a circle of the appropriate size and the plastic will keep the edges from unraveling. If you want to make it really easy, go to the hardware store and buy an arch punch the right size for patches and just punch them out like cookies.
Put a little resin on the prepared skin, flop the patch on with the plastic still intact (be sure you line up weave of the cloth with the fibers of the skin). Use a knife to carefully pull the plastic off of the surface of the patch. Then, use some clear Mylar packing tape and just pull it tightly over the patched area. The epoxy will not stick to the tape.
When it's dry, just pull off the tape. No sanding, no mess and a perfectly smooth surface.
If the patch is bigger, simply lay a piece of Mylar over the patched area, put some foam on top for pressure and tape it down tight. There's no reason you should ever have to sand a properly done repair.
If this seems like too much work, take the glider to your local dealer for an inspection and touch up. I strongly suggest getting any patches you have done using some other method repaired correctly.
2 topics in this article: carbon fiber, Steve Daleo
V-tails, and more »
Fri, Sep 20 2002, 1:00:00 pm EDT
carbon fiber|Florida|Pat Denevan|Ron Gleason|Russ Locke|V-tails
carbon fiber|Florida|John "Ole" Olson|Pat Denevan|Ron Gleason|Russ Locke|V-tails
(?-i)John "Ole" Olson|carbon fiber|Florida|Pat Denevan|Ron Gleason|Russ Locke|V-tails
carbon fiber|Florida|Pat Denevan|Ron Gleason|Russ Locke|V-tails
Felix Rühle «felix» writes:
The tails have passed the DHV car, load and flight test and they are now available.
This is great news. I’m not sure of all the tests that the tails had to pass, but last time I heard about this, I thought it was with the glider and tail together. True?
I wonder if DHV or AIR will publish the pitching moment and pitch damping curves. It sure would be great. I wondered earlier if DHV tests for pitch damping. Do they?
It sure would be great to know a lot more about these tests and what they mean to pilots. Does it mean that the ATOS is much safer to fly with a V-tail? That is it much more resistant to tucks and tumbles?
Felix writes:
In your last report, a pilot mentioned bar movement at high speed with his standard harness, but not with the mosquito harness. Flying into a thermal usually causes a pitch up moment and the bar wants to move forward. The pilot usually pulls in when the bar is already starting to move back to the neutral position.
Had a discussion about this with Pat Denevan (ATOS dealer) and Ron Gleason (ATOS pilot) today. Pat states that you can just put your palm in front of the bar and pull in with no fingers around the bar, just a straight hand. Then watch the bar go back away from your hand toward your chest a few inches. The ATOS pitch movements happen without pilot input and according to Pat are most evident in stable conditions or flying at Funston, where there aren’t thermals, so that you can see the bar move without confusing that with movement due to thermals.
We felt that pilot weight might play a big part in this issue (or a pilot plus a mosquito). Felix is a big guy, so he has never had to feel what an ATOS feels like when you weigh a lot less. Ron has never felt these pitch movement issues. He’s pretty big also. Other pilots have never felt them. Russ Locke, for example.
This doesn’t prove that weight changes the pitch characteristics of the ATOS, and we don’t have an explanation about why this would be the case, but it is a tantalizing hypothesis.
I know that I didn’t mind the ATOS in Floridawhen I was racing with 22 extra pounds in the competition, but I attributed that to my focus on competition. I had ballast in Big Spring, Texas, and was often unhappy and scared, but the air there was quite a bit bigger than Florida.
I did not feel good (experienced lots of pitch movements) in Floridawhen I was flying around after the competition without ballast, and before the competition without ballast in a Stalker 2.
Of course, the V-tail in Chelan made the glider feel just a whole lot better.
Felix writes:
The best way to handle turbulence (small turbulence at high speed) is to press the elbows to the harness and hold the bar close to the harness. This is not possible when the hang strap is too short.
This is an extremely interesting point and the first time I have heard this. I did shorten my hang strap in order to allow me to get more head down in pulled in position. I would like more clarification of this point, that is, how close to the bar should we be on an ATOS-C when the bar is at our chin, our neck, and our chest?
I shortened the hang strap this spring from where it was at when I was in Australiain January (new Carbon Fiber CG harness). I will lengthen it (the strap on a Carbon Fiber CG is adjustable) when I get back to Australia.
I really hope that Felix writes back about this and gives his best guidance around this issue.
Felix writes:
I fly with the Mosquito too and feel no difference, but a big difference with different hang strap length.
I wonder just how big a difference this makes in how the pitch movements feel.
Felix writes:
Additionally the motor at the harness tail moves your CG back. The bar with the Mosquito is usually about 15cm back (the glider stalls with the bar 15cm more back!). This causes an other arm position at high speed too.
This is pretty confusing and I couldn’t figure out how to edit it. I thought that the bar would be further forward not back. Maybe Felix can help me out here.
Felix writes:
My experience is that there is no influence to the stall behavior from slightly bent tips. The glider of the pilot who experienced this is currently being checked at our distributor in GB, Steve Ellkins, and will be test flown also.
6 topics in this article: carbon fiber, Florida, Pat Denevan, Ron Gleason, Russ Locke, V-tails
SparrowHawk »
Wed, Sep 4 2002, 12:00:01 pm EDT
carbon fiber|David Glover|Gary Osoba|Greg Cole|PG|sailplane
carbon fiber|David Glover|Gary Osoba|Greg Cole|John "Ole" Olson|PG|sailplane
(?-i)John "Ole" Olson|carbon fiber|David Glover|Gary Osoba|Greg Cole|PG|sailplane
carbon fiber|David Glover|Gary Osoba|Greg Cole|PG|sailplane
Check out the previous articles on the SparrowHawk (OzReport.com/Ozv6n176.htm, OzReport.com/Ozv6n40.htm, and OzReport.com/Ozv6n33.htm ).
According to Greg Cole, the chief designer of the SparrowHawk, it was designed to be an affordable glider with reasonable performance, somewhat along the lines of the PW-5, but with better performance.
Greg wanted good performance at high speeds so that the glider could get around the course in a hurry. He wanted a low inertia glider that had quick response. According to Gary Osoba who probably has the most hours on it, it is as good as or slightly better than his Woodstock, in roll rate, about 2.2 second to go from 45 to 45 degrees (at 1.4 times the stall speed). Garyhas tuned his Woodstockfor the fastest roll rate possible to allow him to take advantage of microlift.
The SparrowHawk is designed to be easy to handle at low speeds. For safety, the cockpit is large and comfortable with more than adequate ventilation. Plenty of room for water and food to keep the pilot alert.
With its light weight the glider should have relatively slow speeds when approaching the ground, thereby cutting down on the forces that would be encountered from miscellaneous impacts. The cockpit is designed as a crumple zone that absorbs the shock of impacts.
The pilot is protected by the structure around the pilot just in front of the wheel. If the wheel is smacked in, it absorbs the impact behind the pilot.
According to Greg, the SparrowHawk is easy to repair and can be repaired by any composite technician found at sailplane ports. The manufacturer provides epoxy and carbon fiber for repairs.
All the control cables are made from an aramid, Technora, rope that is used in sailing for all the rigging on America’s Cup sailboats. The Technora ((http://www.teijin-aramid.com/ENG/tech_frame.htm) is housed in a Dacron sheath.
Greg has had considerable experience working in airplane manufacturing with the certification process and one of his goals was to build a plane that did not have to be certified (which considerably reduces the costs) and could therefore use technologies that are not certifiable. For example, 1/8” steel wires are required for cables in airplanes, and he wanted to use stronger and lighter Technora. You’ll also find Technora used in paragliders (http://www.nova-wings.com).
To build an affordable glider it is important to think about every part of the glider. The lighter the glider, the greater chance to cut the costs. For example, the light flexible canopy costs $300. Compare this with the cost of other sailplane canopies - $1,500 and up.
The span loading (that is loading per foot of span of the glider) is 9.7 to 11.5 lbs/ft, about that seen on 15 meter sailplanes.
I don’t have a sufficient understanding of the wing construction. I do understand that first the carbon fiber spar is constructed. There are two additional longitudinal shear webs that along with the spar form the torsional boxes that accept the torsional loads on the wing. The trailing edge does not have to have additional connections between the upper and lower surfaces due to the rear shear web.
Apparently the spar itself can handle all the torsional loads, and the additional shear webs form redundant torsional boxes that can handle the load if the spar becomes unattached to the wing surfaces.
The Yellow SparrowHawk.
Why is this SparrowHawk painted yellow? Because it can be.
Ever wonder why sailplanes are painted white? To keep the fiberglass from softening up. The SparrowHawk is cured at 270 degrees. You can have it painted any color you want.
The paint is two part polyurethane paint – automobile paint. You can have it repainted down at Earl Scheib’s. You can go to the paint store and they can make you up some paint spray cans with your favorite color.
David Glover lifting the fuselage
Because it is light, it is easy to move around. Seemed to me like it would be possible to strap the whole thing on your roof rack. It is easy to setup because it is so light.
The SparrowHawk is a sports car. It is built stiff out of carbon fiber. Expect a rough ride in turbulence. Expect to be able to feel everything in light lift. Expect to feel connected to the air.
Greg’s claim was that this was a sailplane for the 21st century. This is a big claim and a lot of it has to do with his use of advanced carbon fiber techniques that apparently haven’t been picked up by the Germans and their spin offs. Perhaps we are ahead of the Europeans in this area after all.
Apparently the SparrowHawk is the first production sailplane built in the USin twenty years.
6 topics in this article: carbon fiber, David Glover, Gary Osoba, Greg Cole, PG, sailplane
Prepreg and tailplanes
Mon, Sep 2 2002, 6:00:04 pm EDT
carbon fiber|Greg Cole|John Vernon|sailplane
carbon fiber|Greg Cole|John "Ole" Olson|John Vernon|sailplane
(?-i)John "Ole" Olson|carbon fiber|Greg Cole|John Vernon|sailplane
carbon fiber|Greg Cole|John Vernon|sailplane
john vernon«johnv» writes:
Through the development of the tailplane unit I became increasingly convinced about the use of prepregs, and my tailplanes are made from these materials to achieve the desired strength at a very light weight. TheUK is well positioned in this field through, amongst other things, the concentration of racing car constructors here, which has lead to many developments in this area. One of the drawbacks of the material is that it must be transported and stored at -18 degrees C. So it is normally packed in dry ice for transport and kept in freezers until required for use.
I think one of the reasons for not apparently using this material in current class five gliders, is that some of the components are often made in the old communist block countries ofEastern Europe to take advantage of the skills available there at low wage rates, which favours the more labour intensive wet lay up techniques. However I understand that the techniques used, emulate, to a certain extent, the production of a "pre-preg", albeit carried out by hand and therefore without the full advantages (high fibre volume etc) of a machine impregnated cloth, and using resins which by necessity employ extra constituents (as you suggested) which are avoided by the pre-preg process.
I have just completed a website about my tailplane products which gives a brief description of construction materials etc. It’s at www.slipstreamcomposites.com.
(editor’s note: The Pacific Northwest has always been a hotbed of composite work because of Boeing. For example, the first composite water skis came out of Redmond. Boeing continues to press forward with composites, especially on their newly proposed aircraft. Weight/operating cost is the issue.
The carbon fiber material used by Boeing and produced by Toray appears to be far advanced over what is available elsewhere, although Airbus should have access to something similar. Greg Cole is the first designer/manufacturer to incorporate this type of advanced pre-preg carbon fiber (although not exactly what Boeing specifies, which is a trade secret) in sailplanes. The particular pre-preg carbon fiber used by Greg is now used in other aircraft.)
4 topics in this article: carbon fiber, Greg Cole, John Vernon, sailplane
The SparrowHawk
carbon fiber|Greg Cole|NASA|SparrowHawk|William "Gary" Osoba jr.
I have spoken extensively with Greg Cole of Windward-Performance (http://www.windward-performance.com) the maker of the SparrowHawk. I was most interested in the construction of this 155 pound glider. I wanted to know how they could make such a light glider, but expect it to test out at destruction to + and – 9 g’s. The plane has not yet been tested to destruction.
The SparrowHawk is built using pre-preg carbon fiber cloth that is built to a specification that came out of work at NASA. Each batch of the cloth is tested and certified by the manufacturer to meet this specification.
Very high quality pre-preg carbon fiber cloth reduces significantly the variability normally found in carbon fiber construction, especially in wet lay-up construction. Large pieces can be constructed at room temperature with multiple carbon fiber pieces and then bagged and heated in an oven to create one consistently strong piece. The SparrowHawk parts are cured at 270°Fahrenheit.
The pre-preg cloth is provided by Toray in Tacoma, Washington(http://www.torayusa.com). This company also provides pre-preg carbon fiber cloth for Boeing (http://www.torayusa.com/tca/products/prepreg.htm). Toray is the first Boeing composite prepreg material supplier for primary structure to be allowed to be allowed to inspect and certify the quality of the material going to Boeing.
Toray uses a 10 million dollar machine for the hot melt film process that bonds the resin to the carbon fiber cloth. This allows for the high level of consistency.
The carbon fiber cloth is made from fibers that have a strength of 700,000 psi, twice that of normal carbon fiber.
The SparrowHawk is the first aircraft to use this specific cloth, but now it is used in Adam A500 (http://www.adamaircraft.com) and the Liberty XLS airplanes.
Greg uses Divinycel HT50 foam cores. HT stands for high temperature. This is the foam core used with pre-preg carbon fiber and high temperatures (http://www.diabgroup.com/DIAB/
DIABHome.nsf/StartUS/$first?OpenDocument).
All the components of the SparrowHawk have been load tested and have all passed their design loads. The wings have not yet been tested to failure, but this is planed for the first production model, the one that Gary Osoba flew for three world records.
All the tools/components used to construct the SparrowHawk are built out of steel and carbon fiber with 350° epoxy resin. The models are eight layers of carbon fiber and two middle layers of fiberglass. The coefficient of expansion of the molds is the same as that of the parts.
Greg says that the SparrowHawk was designed to be simple to fly and have a crispy response to the air conditions encountered while flying. The carbon fiber construction allows for a stiff air frame which lets the pilot feel the air. You might notice that its 36 foot wing span is about equal to that of a flex wing hang glider.
Greg previously was the Chief of R&D at Lancair Company where he worked on the certification of the Columbia300 and Legacy 2000 wings.
Discuss "The SparrowHawk" at the Oz Report forum link»
5 topics in this article: carbon fiber, Greg Cole, NASA, SparrowHawk, William "Gary" Osoba jr.
Checking the ATOS-C control frame after whacking
Sun, Aug 18 2002, 2:00:01 pm EDT
carbon fiber
On the last day of the US Open I had the misfortune of dropping out of the sky a little too quickly in the last ten feet. Fortunately the ATOS-C (and Stratos) control frame and especially the weaklinks in the downtubes absorbed almost all the shock of landing in a nice soft plowed field.
The weaklinks took most of the shock. The rest of the shock was absorbed by the pip pins in the corner brackets and by the right corner of the control frame, in particular the epoxy within the control frame. The pip pins are hollow and they are designed to absorb the shock of the control frame contacting the ground by bending, just like the stainless steel weaklinks in the middle of the down tubes. After a particular hard landing you’ll need to replace these pins.
The idea is to absorb as much shock as possible so that the keel stays intact and the carbon fiber control frame also stays intact. The epoxy in the control frame took the rest of the shock and cracked around the edges at the connection between the base tube and down tube. Here’s a shot of the right end of the base tube and one of end of the right down tube.
You can see that the two outside layers of fiberglass have been separated from the interior epoxy and that there are chucks of epoxy missing from the now rounded off corners of the end of the base tube.
You can see that the epoxy has been cracked and the outside layers of fiberglass separated from the epoxy at the end of the downtube. The cracks don’t go very deep, and are really just cracks in the corners.
The ATOS -C control frame is constructed of carbon fiber roving layed up and then surrounded with black epoxy resin. If is very difficult to actually see the roving that is the structural portion of the control frame as except for some white threads it is the same color as the epoxy.
The outer layer of fiberglass, which is what you see when you look at the control frame, is just for UV protection, to look good, and to indicate any cracks in the interior. The roving inside is doing all the work.
I’m told that there are 11 layers of roving that make for a strong structure. The roving is wound around the holes where the pip pins go. When checking for damage you need to check around the holes to see if the roving (and not just the epoxy around it) has cracked.
The load from hitting the right corner of the control frame into the ground was distributed finally to the square edges of the right hinge. These edges are just epoxy and they cracked. The interior roving did not show any cracks. Felix states that he has yet to see any cracks in any of the roving on any ATOSes that have suffered similar fates.
When I checked the ends of my base tube and downtube I found that the epoxy had been damaged but there was no damage to the roving. The pin in the right hinge was bent, but a new pin would continue to hold together the base bar and down tube.
Felix suggested that I round off the base tube as follows:
This would make it easier to connect the down tube and base bar. But it would also add a bit of play to the control frame allowing the downtube to bow out a bit. I don’t know if I want that, but at the moment I have gone along with him on this suggestion.
I removed the broken epoxy and sanded off the surface as well as removing the cracked optical outer layer of fiberglass. I found some voids in the epoxy and filled them up. I also put some finely woven carbon fiber on the outside as UV protection.
Obviously, if the roving is cracked them you’ll have to get a new base bar or downtube. So far no one has had to do that. It is easy to check to see if you have cracked the roving and easy to repair the epoxy if that is the only problem.
1 topic in this article: carbon fiber
Carbon fiber repairs
Thu, Aug 15 2002, 6:00:03 pm EDT
carbon fiber|Felix Ruehle|Scott Rutledge
Quite a while back we published on-line the carbon fiber repair manual originally put together by Scott Rutledge with pictures that he took of Flight Design’s Felix Ruehle (then) and Joseph Stellbauer’s work. The workshop happened in Ellensburg, Washingtonand we all had a great time.
There is a new version of the carbon fiber repair manual up at http://groups.yahoo.com/group/RigidWing/files/
Carbon%20Fiber%20Repair/FD_GB_Repairs.doc.
I‘m sure that you can also find it at www.flightdesign.com.
3 topics in this article: carbon fiber, Felix Ruehle, Scott Rutledge
Flipping for dollars
Wed, Aug 14 2002, 6:00:01 pm EDT
carbon fiber|record|sailplane
Hang gliders get flipped over in the air a lot more often than we really would like. Hang gliders are tailless aircraft and it is a lot easier to get them upside down than it is to get an airplane upside down.
Think about all the tucks and tumbles that I’ve reported over the last year of both rigid and flex wings. Think about the fact that I don’t know about a lot of the ones that did get upside down.
Sure tucking or tumbling is a relatively rare event for a hang glider, but it is almost unheard of for sailplanes. I doubt that a sailplane would go inverted in any of the conditions that caused the hang gliders that I have reported on to go inverted.
What this means to me is that sailplanes are just a lot more stable than hang gliders. Maybe this is obvious, and it is once you say it, but it is something we as hang glider pilots ignore. We fly craft that can go over a lot easier than the craft that sailplane pilots fly.
Now this fact has a consequence. It means that we are aware of the fact that we can go upside down. Sailplane pilots only have to worry about this in the rotors of mountain wave. Sure they might go try this at Minden, but hang glider pilots are launching in the lee of the Sierras right up the road from Minden, for god’s sake.
Hang gliders seem to be a lot weaker than sailplanes. The DHV strength standards appear to be less than the requirements for sailplanes. Hang gliders are bending or breaking when they tuck or tumble.
Now it is possible to break sailplanes but it is quite a bit more difficult than it is to break a hang glider. This fact has some consequences also. Hang glider pilots with this knowledge feel that there is a lot better chance that their hang glider will break, especially if it tucks or tumbles, than if they were flying a sailplane. Sailplane pilots don’t really have to worry about breaking their craft unless they put it into a spiral dive or get caught in the rotor of a very strong mountain wave.
Now most sailplanes can be spun a lot easier than flex wings or even rigid wing hang gliders. A big problem with sailplanes is that the pilot can get careless and come into an approach too slow or make a quick turn with too high an attitude and get too high of an angle of attack and spin the sailplane into the ground before it has a chance to recover.
Hang glider pilots can break their leading edges by hitting them with their bodies. The leading edges may break even without the pilot hitting the leading edges, but the point is the pilot is freely hanging in a hang glider. The pilot is tossed around when the hang glider tucks or tumbles. The pilot is likely to be thrown into the wing.
Smacking the leading edges with a pilot in a tuck or tumbles is a natural part of the hang glider tuck or tumble, but hang gliders aren’t built to withstand this impact. Pilots of sailplanes aren’t being thrown into their wings when the sailplane gets vertical. Sailplane pilots aren’t breaking their wings by smacking into them.
Hang glider manufacturers seem to want to blame the pilots for breaking their wings by hitting them as though somehow it is the pilot’s fault and the manufacturer shouldn’t or couldn’t build wings that should be ready to take the impact of pilot’s bodies swinging into them. It seems to me that the pilot hitting the wings is just a natural part of the tuck or tumble and we would all like the wings to be able to take this impact if the pilot isn’t in a fuselage or a cage.
In tumbles, where the glider rotates very quickly to the upside down position, say within 2/10th of a second and where the glider wasn’t going fast to begin with and didn’t have a chance to pick up speed, it appears as though there can be minimal damage to the hang glider. The pilot often lands on the keel and doesn’t hit the leading edges. This is the strongest part of the glider.
The pilot’s body doesn’t pick up speed, and the glider just rotates about him. The pilot lands in the apex, and the control frame absorbs the shock. The pilot hits the sail and not the aluminum or carbon fiber leading edges. The pilot is able to get the glider righted or it rights itself and can continue to be flown.
The leading edges on rigid wings appear to break rather easily in the tuck or tumbles situation, surely when the pilot’s body impacts them, and perhaps under other loads as well. The reason incident with Guenther Tschuring in Chelan may have been a case where Guenther impacted the leading edge without realizing it because, again, things happen so fast that your mind just can’t record all the details.
Gilbert tumbled his ATOS and recovered. Jon Woodruff did the same to his Airborne Climax. They both rotated very quickly and landed in their apexes. Other flex wing pilots broke their gliders in tucks and tumbles that didn’t happen quite so nicely.
Rigid wing without tails definitely have a problem with low pitch dampening. This means that they can go over very quickly and easier than flex wings which have higher values of pitch dampening.
I haven’t heard any stories of Swifts going upside down. So far the claim is that they never have, but then there aren’t that many of them either so the opportunities to go over have been quite a bit fewer. They have gone vertical but not over. Maybe in this way they are more like sailplanes (they hate it when I refer to them as sailplanes, but maybe they shouldn’t).
The pilot is fixed (pretty much) in the cage in a Swift so he isn’t going to cause a problem with the CG going back and he isn’t likely to be thrown into the leading edges. These are two big reasons to think that a pilot has a much better chance of surviving a tussle with an invisible dragon in a Swift than in a rigid wing or a flex wing hang glider.
Basically what this means is that the parachute is the basic means of dealing with the weaknesses of the hang glider. There is air that we fly in that will get us inverted and will lead to events that often break the hang glider. If we fly long enough we will be in that air and we will need to throw our chutes.
At least we don’t have to crawl out of the canopy, get away from the airplane and then throw our chutes. Of course, if we do this close to the ground in either craft all bets are off.
3 topics in this article: carbon fiber, record, sailplane
More than a salad bowl
Sat, Jul 27 2002, 5:00:03 pm EDT
carbon fiber|George Longshore|Manfred Ruhmer|Niki Longshore
George Longshore «longshore2» writes:
I took the stock soft lining out of my salad bowl with string and replaced it with a polystyrene helmet liner from a Boeri Skiing helmet. I also layed up 2 layers of Kevlar and 2 layers of s-glass inside the shell of the salad bowl so that if I do hit something hard it will not turn into a pile of carbon fiber dust. (carbon fiber has the lowest impact modulus of all the composite materials.)
I do like the aero shape of the salad bowl but was worried that it wouldn't take much, if any abuse. I'm sure that Manfred does not worry about a bad landing now and then, but my landing history proves that I need to worry about things that the world champion does not.
The mods to the salad bowl turn it into a real helmet with real impact resistance and head protection with out adding too much weight, a few ounces at most. Why will Icaro not offer this version as the stock version? It could then be certified and even more pilots would buy them. The soft lining that comes stock is a joke and I would not want to trip and fall while walking with the protection that it offers.
4 topics in this article: carbon fiber, George Longshore, Manfred Ruhmer, Niki Longshore
How strong and flexible are rigid wing hang gliders?
Sat, Jul 27 2002, 5:00:00 pm EDT
carbon fiber|Felix Ruehle|Manfred Ruhmer|Ron Gleason|sailplane
carbon fiber|Felix Ruehle|John "Ole" Olson|Manfred Ruhmer|Ron Gleason|sailplane
(?-i)John "Ole" Olson|carbon fiber|Felix Ruehle|Manfred Ruhmer|Ron Gleason|sailplane
carbon fiber|Felix Ruehle|Manfred Ruhmer|Ron Gleason|sailplane
There has been some discussion on the rigid wing list lately about the strength of rigid wing hang gliders. I decided to ask all the rigid wing hang glider manufacturers just how strong their gliders were. I sent out a version of the following message to AIR «info», Icaro «staff», Flight Design «flightdesign», Joseph Guggenmos «Drachenbau.JGuggenmos», La Mouette «lamouette», and Aeros «aerosint»:
After Guenther's broken wing in Chelan there is renewed interest and concern regarding the strength and flexibility of the ATOS (and other rigid wing) d-cells. I have previously forwarded to you some of those concerns.
ATOS pilots and others would like to have the assurance that their wings are as strong as they need to be to fly in any of the conditions that we would reasonably expect to encounter in competition and cross country flying. While I'm sure that the answers that we are looking for can involve long and detailed study and explanation, perhaps we can start off with a few basics.
First, the published rating for the Swift Light is Maximum load +6/-4 g, tested +8,7/-6 g. While it is unclear whether this is design load or ultimate load, perhaps you can provide us with the rating for the ATOS-C.
Second, do you use a 50% safety factor to differentiate between design load and ultimate load?
Third, do you design the ATOS to meet JAR 22 specifications?
Fourth, describe the construction of the ATOS spar and d-cell particularly with respect the sparcaps and how the spar is made to operate like an I-beam, if this is in fact the case.
Fifth, there appear to be at least two versions of the ATOS, single and dual place. How much stronger is the dual version and how much stronger would a version be that added about 5 kilos of optimally placed carbon and resin to the single place version?
So far I have received answers from three manufacturers, AIR, Icaro, and La Mouette. I got the following from Felix Ruehle at AIR:
I really appreciate that you are working on this because I think many people are concerned. Still it's not clear to me why Günther’s ATOS broke and there are a few different possibilities. Yesterday, I heard that Günther’s transport box had been damaged with a fork lift when the glider was shipped to Chelan. I expect to get the parts including box back within the next days for further investigations.
The Stratos is tested to a load of about +8900N (ultimate load) and about -4600N, on the DHV test rig. Considering the lower span of the Atos, this is equal to a load of approximately 9200N. According to the DHV requirement, the ultimate load must be higher than hook in weight of the pilot + half the weight of the glider multiplied with 6. This is equal (approximately) to a 6g load positive. Negative, the multiplication factor is 3. The Atos is certified to a maximum take off weight of 150kg.
To clarify what Felix wrote I asked him:
Okay, just to be clear the ultimate load (the load to which the ATOS is tested) for the ATOS is: +6g/-3g?
The design load of the ATOS is +6g/-3g?
It would appear that the Swift Light is static load tested (not on the rig) to 8.7g and -6g. Has the ATOS been static load tested? Results?
Felix wrote:
It's better to compare the maximum load where the glider was tested and how it was tested. For example, the whole glider on a test vehicle or only the spar. If you take Günther’s weight and the maximum tested load, you will get about 10g (don't know exactly how much ballast he had). If you have the total loads it's easier to compare the gliders. Then the pilots have an idea to how many g’s this corresponds to.
The JAR 22 specification is +4g and -2g with an additional safety factors of 1. 5 and 1.15 (for composite materials). The ATOS-C almost meets these requirements. The JAR 22 requires testing at 54 °C and the wing has to hold the load for 3seconds. The Atos is designed for these loads, but it is not tested at 54° C because the DHV test is on a car outside. The resins used in the ATOS are the ones used in sailplanes as well. The Atos spar's are tempered at higher temperature than sail planes in order to resist higher temperature.
I asked:
The JAR 22 specifications would be 6g/-3g before the consideration of composite materials, and 6.9g/-3.45g for composite materials. The ATOS meets the JAR 22 specification if we don't consider the additional factor for carbon fiber?
Felix wrote:
The Atos is certified up to a total take off weight off 150 kg. According to my calculation this is equal to about 7.2 g (tested load) and meets the JAR 22 in this case. With a hook in weight of 100 kg it is about 8g and with a hook in of 80 kg it is 9.7g. The g loads are calculated and not tested in flight. It's better to compare the ultimate strength. Because there are different ways to do the calculation, I would suggest comparing ultimate loads.
Upper and lower main bolt fix the wing. These bolts are fixed with carbon fibers which are wound around the bolt. These fibers (spar caps) are located at the very top and lower side of the spar and are tapered out to the wing tip. Between the spar caps is the spar wall, which takes shear and compression loads. The U-spar is fixed with a skin (C section of the wing) in order to get a D cross section which takes the torsion loads. Spar wall and skin are manufactured with a foam sandwich in order to avoid buckling.
The Atos is designed with approximately the same keel and a similar lay up to the Exxtacy. The inner spar is additionally reinforced. While the Exxtacy will usually fail (at load test) at the spar connection (the nose rings), the Atos spar will fail between rib 1 and 2.
We worked on a tandem version and produced prototypes with higher strength, but there is currently no tested tandem version on the market. Since May of this year the Atos has an additional glass layer at the spar wall which works as a damage indicator but with only a minor influence on strength.
When I asked Icaro about the Stratos, Saskia wrote:
The Stratos has the same structure and parts as the Atos, except for small details. Also for the future we will continue the cooperation with AIR for all the new developments (and we pay a royalty for every Stratos we sell). I am convinced that Felix is a very good engineer and with the trio Felix, Christian and Manfred we will make exceptional and safe wings.
I think that you asked the same questions to Felix, so you can use his reply for both rigid wings.
My response to Saskia was:
I thought that perhaps that Icaro might have specified a slightly different version of the ATOS d-cells. Felix made the unfortunate statement here in Chelan to Ron Gleason, theUSteam leader and ATOS pilot, that, "AIR could make up anything you like in a d-cell." He also said that Alex's ATOS-C was stiffer than other ATOSes with more carbon fiber to keep the leading edges from bending at higher speeds and thereby keeping the trailing edge tighter. I thought perhaps Icaro might have such a version on their Stratos.
Gerard Thevenot wrote:
Adding extra kilograms to a wing already designed, tested and certified might be dangerous, concentrating stress on some points and stiffening the wing thus not absorbing any more the turbulences and shocks.
Actually on my next design I would like to taper my leading edges even more to have a better stress repartition (+ saving weight and handling).
The TOPSECRET has been tested to 840 KG positive and 420 negative without failure. But, again, I would rather fly a rubber glider tested at 2 g's, but unable to reach them, than an undeformable glider tested at 10 G's.
Ultimate load: Carbon has very different mechanical characteristics from metals. It practically does not permanently deform before 97 % of its failure limit.
I am not familiar with JAR22 as I think it is related to standard aviation and our hang gliding landing gear would never pass the specifications.
As far as I have been able to see, our leading edges are quite different from other manufacturers.We are using a main spare for vertical flexion and the front skin for horizontal flexion and torsion.
I have asked Gerard some additional questions and will publish those answers when I get them.
I will have additional articles on this issue and hopefully other responses from manufacturers.
5 topics in this article: carbon fiber, Felix Ruehle, Manfred Ruhmer, Ron Gleason, sailplane
ATOS – transport damage? »
Sun, Jul 21 2002, 5:00:04 pm EDT
Alessandro "Alex" Ploner|ATOS|carbon fiber|Davis Straub|dust devil|Johann Posch|Richard Christen|Tryg Hoff|video|Werner Schnitzler|Wills Wing
Alessandro "Alex" Ploner|ATOS|carbon fiber|Davis Straub|dust devil|Johann Posch|Richard Christen|Tryg Hoff|video|Werner Schnitzler|Wills Wing|World Record Encampment
Alessandro "Alex" Ploner|ATOS|carbon fiber|Davis Straub|dust devil|Johann Posch|Richard Christen|Tryg Hoff|video|Werner Schnitzler|Wills Wing|World Record Encampment
Alessandro "Alex" Ploner|ATOS|carbon fiber|Davis Straub|dust devil|Johann Posch|Richard Christen|Tryg Hoff|video|Werner Schnitzler|Wills Wing
I had an opportunity to speak at some length (although not for long enough) with Guenther Tschurnig after the closing ceremonies on Sunday about his incident (you remember, his wing got torn off in a dust devil). Guenther felt that there was the possibility of damage to his d-cells from the car racks experienced while going up the butte.
Four of the Austrian team’s ATOSes were hauled up the butte on top of Johann Posch’s VW van. The ATOSes were stacked two deep. (We were never allow rigid wing gliders to be stacked on our vehicles.) The racks on Johann’s van are round, thin, and poorly padded. (The racks on my truck are 3 inches wide, flat and well padded.)
The road up the butte was well maintained for a dirt/gravel road, but still it could be a bit rough. Guenther had been here for three weeks including the Chelan Cross Country Classic.
The spot on where the wing broke corresponds to where the wing was sitting on the rack. It wasn’t clear from my conversation whether there were any signs of rack damage on the wing, although I tried to get this question answered numerous times.
One problem with this theory is that the damage on the wind would have been on the top surface (although also possibly in the spar). The wing would seem to have torn from the bottom surface if it was under a positive load.
Felix is taking Guenther’s ATOS back to Germany and will perform a series of tests on it and on the other d-cell that wasn’t damaged in flight to see if it breaks in the same spot under a high load. He will write up a report. I hope to be able to publish it.
Four pilots who’ve broken ATOSes in the air: (Tryg Hoff, Davis Straub, Guenther Tschurnig, and Richard Christen.)
Tryg isn’t flying hang gliders yet. Richard bought Alex’ Ploner’s beefed up ATOS-C on Sunday, after flying on Saturday the one Alex flew in Texasduring the WRE. I’m flying a tandem version of the ATOS-C. I think that Guenther will get another ATOS-C in Austria.
Werner Schnitzler «w.fly» provides a very much speeded up version of a discussion that I had with Richard Christen about tucking and tumbling:
http://werner.kicks-ass.net/ThereIWas.wmv, Windows Media Player Video Clip, 2.8 MB
Of course, the rack damage theory can be viewed as a very convenient theory. It lets Felix and AIR off the hook. It lets the rest of us ATOS-C pilots off the hook (at least until one of us tucks or tumbles again). At the moment it is only a theory with a very small amount of circumstantial evidence.
On the other hand, if the ATOS d-cells are indeed designed and manufactured to sustain a 10 g load, then it does explain why such a strong wing could fail under a load that was most likely under 10 g’s (so we think). Another possibility is that there was a failure of the manufacturing process.
One fact does give us pause. Wills Wing load tests every carbon fiber spar that they get from the subcontractor before they install it in one of their Talons. I have heard that only one has failed so far during this static load test.
ATOS spars (and perhaps the spars from any or all of the other rigid wing manufacturers) are not static load tested after they are delivered from the subcontractors. Therefore there is not test at AIR (or at Icaro?) that verifies that the d-cells have met the manufacturing requirements.
11 topics in this article: Alessandro "Alex" Ploner, ATOS, carbon fiber, Davis Straub, dust devil, Johann Posch, Richard Christen, Tryg Hoff, video, Werner Schnitzler, Wills Wing
Worlds – Natalie in first (Kari 11 minutes behind) »
Tue, Jul 16 2002, 5:00:00 pm EDT
carbon fiber|Hansjoerg Truttmann|Johann Posch|Manfred Ruhmer|Steve Elkin|Steve Elkins|Worlds
carbon fiber|Hansjoerg Truttmann|Johann Posch|Manfred Ruhmer|Oleg Bondarchuk|Steve Elkin|Steve Elkins|Worlds
carbon fiber|Hansjoerg Truttmann|Johann Posch|Manfred Ruhmer|Oleg Bondarchuk|Steve Elkin|Steve Elkins|Worlds
http://www.elltel.net/peterandlinda/2002%20Worlds/Worlds%20Main.htm
The web site will be delayed due to the fact that the team leaders are not as up to date as the pilots who are getting on line to see the scores. Until “hard copy” is delivered to the team leaders (anyone remember what “hard copy” is?), at the 8 AMteam leader meeting, there won’t be any new results up on the web site.
Jeez!
The forecast for today was the same as yesterday, 700 fpm to 9,000’. Blue. Light west winds 5 to 10 mph. A fire broke out this morning (I first saw the smoke at 7 amafter getting up and looking at the sky a 6:30 am– so you know it was just starting) on a hill side up the lake a ways on the north side. Smoke would cover the lake until later in the day when the winds picked up and blew it to the north.
After we all got to goal yesterday, Danny (and Scott?) called a women’s task that was the Class 5 task yesterday (Farmer, Sims, and back). The class 2 and 5 pilots were directed to go to a turnpoint near Dry Falls (near Coulee City), north along the length of Banks Lake to almost Coulee dam), then back to Sims Corner and back to the airport in Chelan. This is 160 kilometer task.
When I hear what Danny has called, I ask Kari (Christian didn’t attend the Task Rubber Stamp, don’t have any power any way, only advisory, better to be seen and not heard committee today) to ask for Leahy instead of up near Coulee. This is rejected with a snide comment that Davismust have proposed it. I’m just trying to get a few pilots into goal.
Going over 100 miles and trying to get pilots make to goal by 7:30 with start times of 2 to 3 pm is a stretch. Possible, but difficult. The lift closes down around 7 PM, so the last half hour doesn’t do you much good unless you’ve just made it to the rim and all you have to do is dive in to goal.
The thermals are great at the butte, well the one thermal was. It took many of us to almost 9,000’ and was pretty darn smooth. I’ve got my extra clothes on today so I’m styling at the top of the lift. I’m also flying with a salad bowl and a string as a substitute for a reasonable helmet. Looks like head fairings may be required if you want to move up in the rankings.
Getting so high at the butte makes for an easy flight to the flats and once there we climb out in a gaggle to over 10,000’. Now we are just waiting for the start clock. We can’t wait until 3 PM, because we would never make it back to goal in time.
A few pilots leave at 2 PM, and many go at 2:15. It is a long glide at high speeds to JamesonLakebefore we find the first thermal, a dusty. I’m flying with Hansjoerg, but the thermal is packed. It is so nice to have so many friends along for the ride.
We clock the winds at 15 to 20 mph out of the south. So much for a light day. It looks like it will be difficult to negotiate some of the legs of this task.
The women also send out the top gaggle at 2:15for their shorter task. They’ve also seen that the winds are high and it will be a struggle getting to Farmer. After that it will get better.
Southeast of Jameson we are just pushing out in light lift and heading into a strong head wind trying to make some distance. Finally we catch up with the 2 PMpilots who are in a good thermal and climb out just under them.
The 2 PM pilots and a few of the higher 2:15 pilots head out toward the turnpoint near Dry Falls, while the lower pilots drift back further and continue to climb well. At 8,500’ I take off to follow the lead pilots to the turnpoint with Hansjoerg just behind me.
The lead guys are heading too far to the south and getting drilled. I head southeast right at the turnpoint and get a good line. 5 kilometers out the lead guys are way down and circling in light lift. I’m heading for the turnpoint high and watching three Swifts coming back from the turnpoint to the northwest to join the former lead gaggle in the weak lift.
I dive into the turnpoint, somewhat low and immediately head due north along the course line. I’ve been here before and found the lift. I find it again. Hansjoerg comes back to join me and with one other pilot we get away from 20 pilots who are now way behind and drift downwind toward the turnpoint near the dam.
With a tail wind and good altitude (over 7,000’) we head downwind just finding small bits and pieces of lift. We are in the lead and flying with each other as we work our way to the north east turnpoint. We are going to need to find a really good thermal at some point so that we can be high at the turnpoint in order to be able to come back into the headwind.
Just before we get to the second turnpoint I finally find the thermal we need and we climb out to over 9,000’ as we drift to the northwest in the southeast wind. Now it looks like we will have plenty of pilots out in front of us coming to the turnpoint and marking lift as we head back toward Sims.
There is another fire to the south that is filling the air with smoke near BanksLake. We are just to the west of it and the sun is in the west so the ground is not shaded below us. It looks like maybe a bit later it will be, perhaps cutting off pilots behind us.
We push and push against the head wind finding weak lift, and lots of spotty lift, but patience wins the day and we make it to Sims, where we hope to turn the corner and race to goal. Wouldn’t you know it the wind is now coming from the southwest, so we’ve got a head wind to goal.
The day is getting late. The goal will close soon so we need to press forward. Johann Posch and Steve Elkins join us in the lead gaggle just before Sims as we drive west and get pushed to the north. We find strong lift and we need it to keep going.
We’re northwest of Mansfieldand it is 6:30 PM. I’m mistakenly thinking that the goal closes at 7 PM, like the other days, not 7:30 PM, for this long day. I’m climbing in my own thermal just upwind of Johann and Steve at 250 fpm, while Hansjoerg is circling just off the deck below us. I make a mistake leaving my good enough thermal to join Johann downwind. Bad idea as I don’t find the lift and have to go work something weaker. They join me.
I’m thinking that I have to press ahead as we won’t get to goal in time. I need to find a strong one that gets me up and over the rim only a few short miles away. I make the mistake of leaving my friends behind and will land near the power lines just before McNeelCanyon,
Johann, Steve and Hansjoerg will be the only Class 5 pilots to make it into goal. Manfred and Robin will be the only Class 2 pilots into goal.
Natalie will fly with Kari and the top women pilots and make goal 11 minutes before Kari. Claire and Francoise Mocellin will come in 20 minutes behind Kari and Corrina will be there 6 minutes later. Five women make goal.
Flew with Oleg yesterday. He was doing fine. The previous problem was the loose carbon fiber control frame wires (unlike the standard model) allowed for a wire or rope to come off a pulley and get jammed in the spiral death mode.
Oleg repaired the damage (couldn’t see any on the glider) and was flying in the meet.
It looks like the USwomen are in first place after four days. Don’t know about class 5 or 2. The results won’t be posted until tomorrow.
Doug Pohl says try this URL for Chelan pictures: http://65.187.85.53/whgc2002.htm
7 topics in this article: carbon fiber, Hansjoerg Truttmann, Johann Posch, Manfred Ruhmer, Steve Elkin, Steve Elkins, Worlds
Chelan – Kari is first to goal again »
Mon, Jul 15 2002, 5:00:00 pm EDT
Akiko Suzuki|Alessandro "Alex" Ploner|carbon fiber|Chelan|Christian Ciech|Douglas Pohl|dust devil|Felix Ruehle|Gene Matthews|Hansjoerg Truttmann|Icaro 2000|photo|Worlds 2002
http://www.elltel.net/peterandlinda/2002%20Worlds/Worlds%20Main.htm
I guess the meet organizers want to get a few folks into goal. It was looking bad that Kari was the only women to make goal so far. The women got the little task of Withrow, Mansfield and back to the airport.
The rigid wing pilots were sent to Farmer, Sims Corner and back. The Swift pilots had an additional turnpoint near DryFalls. At least 58 pilots made goal today out of 82 pilots. Now people can worry about how fast they flew.
Today was a very good Chelan flying day. Absolutely blue. Lift predicted to be 600 fpm, and actually we got up to 900 fpm to 9,000’ which seemed to be right also. 50 degrees at 9,000’ which is a little cool if you have on what you wore in Florida. Winds out of the west predicted to be between 5 and 10 mph, which again was about right.
It was a bit scratchy at launch for some people. Kari was down on the last ridge before the soccer field. She just had to contrite on getting up. Lots of pilots were near or just below launch for a few minutes before they slowly worked their way over the butte and into the good lift. We go to 7,500’ before heading out to the flats where we could see some fields filled with dust devils.
The women were launching between the rocks, and the rigids were heading off Green Monster. I’ve never seen Green Monster so peaceful, with it coming straight in at about 5 mph. Beautiful and fun to launch in.
We gaggle up north of power lines on the flats and just stay at 8,600’ waiting for the later start clocks. Almost every one launched early because they weren’t sure that everything would remain copasetic on the butte. Now we had time to kill in the cold air. The start window opens at 2 and stops at 3 PM.
A few pilots head out at 2 and 2:15. I and some others take the 2:30, and others wait for later clocks. The idea is to fly fast using the dust devils and make sure that they don’t catch you. Hard to do.
The great Chelan air has returned, with little effect from the high pressure. The thermals at indeed 6 to 700 fpm and you can climb right up to the 8,000’ inversion before it slows down. As the day wears on it gets better and better with smoother and more plentiful lift, and warmer air.
This is a race, not a contest to see how far you can fly into the wind. The idea is only climb in the strong stuff. A lot of pilots show up at the Sims Corner turnpoint, so I’m in a mood to race as hard as possible back to the airport.
We’ve got to make it to the rim and then dive fast down to the airport to get down to 1,500’ over the airport or the goal keepers will have difficulty getting your goal crossing time. (More on this later.)
Of course with all the pilots diving into the airport we’re hoping that not too much general aviation traffic comes in. There is some, but we work our way around it.
I think Johnny Carr flew after they patched up his Swift Lite. I saw a lot of carbon fiber curing in the sun on top. There are two Swift factory reps here working with the pilots. Felix Ruehle is also here helping out all the competitors flying AIR ATOSes. It is so nice to have factory support on the butte.
I don’t have any real results yet today as I have no idea when pilots started. Francoise Mocellin was in after Kari. Then Natalia Khamlova from Russia, Gudrun Maier, and Francoise Dieuzeide.
Japanese pilot at the parade
Results after two days:
1 |
|
Icaro Laminar MRX |
USA |
1243 |
2 |
VASSORT, Claire |
Moyes Litespeed |
USA |
1009 |
3 |
DIEUZEIDE, Francoise |
Moyes Litespeed 137 |
FRA |
917 |
4 |
BAEUMER, Sybille |
Aeros Combat |
DEU |
915 |
5 |
BRAMS, Rosi |
Moyes Litespeed 4 |
DEU |
909 |
6 |
MOCELLIN, Francoise |
Airborne Climax |
FRA |
896 |
7 |
OKADA, Akiko |
La Mouette Topless |
JPN |
884 |
8 |
PERMENTER, Raean |
La Mouette Topless |
USA |
860 |
8 |
FUKUDA, Ka |
Icaro 2000 Laminar ST |
JPN |
860 |
10 |
SCHOENSTEINER, Monika |
Moyes Litespeed |
DEU |
844 |
USWomen are in first
US Class 2 team is in first
US Class 5 team would be in first except for an action that is currently under protest. Otherwise we are in second. All team results are up on the web at the URL above.
1 |
PLONER, Alessaandro |
A-I-R ATOS B |
ITA |
1761 |
2 |
CIECH, Christian |
Icaro Stratos |
ITA |
1614 |
3 |
CHAUMET, David |
La Mouette Top Secret |
FRA |
1584 |
4 |
RIS, Jurg |
A-I-R ATOS C |
CHE |
1583 |
5 |
FIECHTER, Markus |
A-I-R ATOS. |
CHE |
1531 |
6 |
STRAUB, Davis |
A-I-R ATOS C |
USA |
1470 |
7 |
TRUTTMANN, Hansjoerg |
A-I-R ATOS C |
CHE |
1411 |
8 |
BIESEL, Heiner |
A-I-R ATOS |
USA |
1394 |
9 |
LEISER, Rene |
A-I-R ATOS C |
CHE |
1387 |
10 |
COOK, Steve |
La Mouette Top Secret |
GBR |
1375 |
Douglas Pohl «dpohl» sends in this URL for Worlds pictures:
http://65.187.85.53/aviation/dir_hg/dir_chelan/20020714_
World_Cham pionships/800x600/index.htm
Gene Matthews «skydog63» writes:
People watching at the combined Women's and Men's FAI World Championships in Chelan Washington,USA
13 topics in this article: Akiko Suzuki, Alessandro "Alex" Ploner, carbon fiber, Chelan, Christian Ciech, Douglas Pohl, dust devil, Felix Ruehle, Gene Matthews, Hansjoerg Truttmann, Icaro 2000, photo, Worlds 2002
Airblade ⁢ATOS »
ATOS|carbon fiber|Manfred Ruhmer|Steve Pearson|Valerio Canestrelli|Wills Wing
valerio canestrelli «airblade» writes:
The Airblade Full Carbon control bar for my small Atos features:
- Full carbon fiber and Hi temp. epoxy, hand layered in the molds (that I built too);
- 2 mm. short arrangement, front-rear wires;
- " World Carbon Team " Airfoil, under license from Wills Wing (scaled down to 68 mm. X 16.5 mm. instead of 76 mm. x 19 mm.);
- 2 mm. flap rope, inside the basetube ;
- Airblade finish !
Unfortunately the work required to build this frame is too much, so it is not for sale !
I would like to thank Wills Wing (i.e. Steve Pearson) for the airfoil and all the support that he gave me!
The front and rear wires are fixed to the upper half of the downtubes, like Manfred did (before the new FAI rules). We don’t have this limitation on the cantilevered wings
Discuss "Airblade ⁢ATOS" at the Oz Report forum link»
6 topics in this article: ATOS, carbon fiber, Manfred Ruhmer, Steve Pearson, Valerio Canestrelli, Wills Wing
Broken carbon base tubes
carbon fiber|Kent Robinson|Rob Kells
carbon fiber|cart|Kent Robinson|Rob Kells
Kent Robinson «kentrobinson» writes:
I recently broke my carbon basetube just sitting on the tow rig. It was mounted on a typical platform tow rig but it could have easily been an aerotow cart. Basically, the bar cracked and bent on the right side 3-4" in where it was sitting on the wood. I was being as careful as I could and had even put some foam between the basetube and the wood.
After talking with Wills they advised me that several others had broken while being transported to launch on some type of cart. Evidently the bars are not designed for the focused type of pressure that you encounter on a mount of this type.
Rob Kells advised that the only truly appropriate support would be a board or mount that spans the entire basetube. Rob also advised that the aluminum streamlined basetube is essentially unbreakable and is most appropriate for mounts of this type.
Discuss "Broken carbon base tubes" at the Oz Report forum link»
3 topics in this article: carbon fiber, Kent Robinson, Rob Kells
Oh, oh, spin in!
Sun, Jun 2 2002, 4:00:02 am EDT
carbon fiber|Ghostbuster|Robert Lowe
Robert Lowe «SKYOUT1» writes:
You will recall my report that Jay Gianforte had fallen out of a tree, and busted himself up, and that hang gliding was pretty much as safe as hanging a rope in a tree.
BOFF SOCK ZOWIE
Now I’ve proved it! I have just gotten out of the hospital with the same broken bones, i.e., pelvis, leg, arm, ribs, fingers, toes, jaw after spinning my tightly-tuned GhostBuster into rocks from around 200 ft.
As the spring winds instantly dropped from 20 to zero in the middle of a slow left turn, I spun 3 revolutions, then stared straight at the rocks I was heading towards, nailed it straight down to try to regain airspeed, and lacking another 50 – 100 feet ate it big time into the rocky hill.
The only possible reason for survival at all was the Carbon CG harness, as no one there thought there was any possibility I would be found alive. The harness suffered only a couple of small holes near one leg, some scratches, and is still flyable. The GhostBuster has one wing intact, and another in little pieces.
A pilot overhead said he thought he had heard lightning strike, but it was me going in on the right wing. I will be eternally grateful for the protection this high tech and unusual harness provided. What a strange coincidence after what just happened to Jay, and my sarcastic statements that followed. Aren't you gad you have one too!!!!
Rob is very convinced that the Carbon CG harness was very important to his survival:
I really am glad the harness protected me so much, far more than i ever imagined. My guts would have been sprayed about.
(editor’s note: It would appear from Jay’s description that he has mainly one wing of his GhostBuster to thank for absorbing some of the force of his handing. Breaking a carbon fiber wing into small pieces requires a lot of force and certainly could absorb the majority of the shock of hitting the hill side.
Flying a rigid wing hang glider with a high angle of attack (required to fly it slow in these circumstances) next to the hillside is a prescription for disaster and death. Rigid wing hang gliders stall and spin easier than flex wing hang gliders. Keeping the angle of attack low by pulling in is a continual requirement for flying these gliders.
Rob is a very experienced GhostBuster pilot and it is quite upsetting to receive this story. I have little interest in scratching low and slow in my ATOS on any hill side. Thank goodness for the kinds of conditions I normally fly in.)
3 topics in this article: carbon fiber, Ghostbuster, Robert Lowe
118.1 mile East coast triangle
Thu, May 2 2002, 3:00:01 am EDT
carbon fiber|Felix Ruehle|Ghostbuster|Mark Poustinchian|Quest Air|record|Ron Gleason
Mark Poustinchian «mpousti2000» writes:
Yesterday Ron Gleason and I decided to set a 120-mile triangle task and try to set a new East Coast record from Quest Air. The first turn point was to the NW over the big Dunnellon airport. The second turn point was NE of lake Weir overOcala national forest and then back to Quest Air. It started out like mission impossible on the first leg. We could hardly stay above 2000’.
I towed first and was a couple miles away from Ron. With the massive sink between the thermals and lack of altitude, I needed some help to spot thermals, however Ron got low and I had to keep going or sink out in sink pockets. We survived, however Ron got further behind and I decided to get going alone while the going got better.
About 10 miles from Dunnellon the conditions improved and we were able to get over 4000’ agl. By the time I was to the first turn point Ron was low about 5 miles behind and very low. He had several low saves from 500’ agl. The clouds were getting big and I was afraid that we may not be able to finish the task due to thunder storms.
I was getting over 5000’ agl on the second leg and started to let go of the breaks and flew much faster. The second turn point was difficult due to lack of landing zones. So I made sure to get high enough to make it before heading south to Quest Air. By the time I was over the second turn point I had the anticipated conversion zone all the way to back to Quest Air.
Big clouds were lined up and they actually started to look a little scary. I worked a thermal very close to the last turn point over Ocala National Forest and after that I made a total of 10 turns while I glided 40 miles back to Quest Air. I counted the turns on my track log. The last leg was very fast because I was having trouble with too much altitude. I had to get around some big clouds so that I could see where I was going. Too much lift and big dark clouds made me stuff the bar more and more on my ATOS with the beautiful new sail, new spoiler system and new carbon fiber tips.
By the time I was about 10 miles away from Quest Air over 5000’ agl, Ron was getting close to landing and landed by Lady Lake about 25 to 30 miles away from Quest Air. He watched the thunder storms develop and got a good dose of rain. I got over Quest Air about 3500’ and landed before the rain after 4 hours and 45 minutes of flying.
I lost my recorded points from the start on my eMap GPS. Unfortunately I can’t set the time for recording on this GPS and it is only good for the last few hours of a flight. However, the only part that I lost was ½ of the first leg.
My ATOS flies so much better now and I absolutely love the performance, speed and it’s sweet light handling. I did a little X-C flight with another great X-C pilot (a possible USA World Team member) on the new ACCESS+ and now I am convinced that the ATOS is the glider that I want to fly.
When this pilot and I were flying GhostBusters, I didn’t have a chance on glide when I was gliding with him. This was due to his built in ballast, but now with me on the ATOS and him on the ACCESS+, it is a different ball game. I want to thank Felix Ruehle and Christoph from AIR for putting the new sail on my glider and doing the upgrades.
Now, the new records are well within reach. I don’t do the comps because I hate gaggle flying and I want to be on my own and love the low saves and crossing the big blue holes and going far with my ATOS. I am also working on a great hang gliding screen saver for AIR and it will be ready for free down load soon.
7 topics in this article: carbon fiber, Felix Ruehle, Ghostbuster, Mark Poustinchian, Quest Air, record, Ron Gleason
Stalker 2 »
Fri, Apr 5 2002, 6:00:02 pm EST
carbon fiber|Ghostbuster
As long as I was flying the second version of the Falcon, I thought that I would also check out the Aeros Stalker 2. This is quite an upgrade of the Stalker with the addition of large highly canted winglets to significantly increase the Stalker’s span, and a very refined all carbon fiber control frame.
I had only a short opportunity to fly the Aeros Stalker 2 this evening after flying the Falcon 2 to check out the air. I didn’t just want to jump on the Stalker 2 (my first rigid wing flight since Australia) without knowing what the air was up too. Once I found that the winds weren’t too string and the thermals had died down, I was ready to try the Stalker 2.
Previously when I flew the Stalker I had a lot of trouble controlling it. With lots of hours on flex wings recently I figured that that would be less of a problem with time. I remembered that it towed well, and yes this time it towed as straight as one could ask for in the light conditions (well there were bumps at tree level because the wind was still blowing).
The Stalker 2 towed better than I had remembered was the case with the Stalker, and as good as the ATOS, Ghostbuster or Exxtacy. It was easy to go one handed. Also, of course, it was quite a bit quicker than the Falcon 2 with a lot less bar pressure. Overall towing with it was a pleasure.
I find the smallest bit of lift at 2,000’ over the Ranch and started circling. I was going pretty fast and wondered if I had a too far forward hang point position. I wanted to slow down, but took my time doing that as I didn’t know anything about the Stalker’s stall characteristics.
Lots of folks were watching and were impressed that I could stay up so well. Steve Arndt was still around flying in his Magic Dragon and came in under me, although I was just hanging out in zero lift. I was able to stay over him for a good while, something not possible in the 170 Falcon 2.
I was really enjoying the flight, barely moving the bar to get it to turn. I was able to be in charge of the glider right away unlike the last two times I had flown a Stalker, and that impressed me. I made sure that I made only very small movements.
The Stalker 2 is much easer to turn than other rigid wings, and very close to if not easier than the Falcon. Easier than the LightSport. There is a bit of adverse yaw, but once I noticed it I just realized that I had to wait a bit and the glider would turn in the correct direction.
You would think that the wing tips would slow down the roll rate, and maybe they do, but not so that it would be a problem. I didn’t get the Stalker 2 up on the wing tip, that will come later as I get more comfortable with it and get a chance to wring it out a bit.
I was concerned about the landing, as I had only been landing LightSports, Falcons, and Superfloaters lately. I wondered if I would be coming in a lot faster (and not have any wheels). I sure didn’t want to wreck that nice control frame that seemed designed for speed but not for impact.
I pulled the flaps on close to full to allow me to fly slow close to the ground. There seems to be a lot of resistance to pulling down the flaps, but I could do it. I will have to look at that more and see if I haven’t done something wrong in the setup. The flaps are relatively small so I didn’t expect much in ground speed reduction from them.
I pulled the control bar in to get good speed, but not over speed as I wasn’t sure that I would PIO the glider. I brought it right down to the deck with my feet dragging as I slowly let out the bar. The glider kept flying and slowing down and I wasn’t sure just when it would get too slow and go over instead of allowing me to flare.
Finally I decided to flare and bang, the wing just stopped in its tracks with out much of an effort on my part. I did a regular flare and it stopped right them. People on the ground were impressed as I did a no stepper in light winds.
Everyone was impressed and excited about this new version of the Stalker. Lots of folks around here want to fly it, so I’ll be able to garner lots of impressions. I’ll report as fully as I can.
I’ll have an opportunity to fly this glider during the next few days at least, so that I can give a fuller report. Of course, what every one is really interested in is its performance compared with the current leader – the ATOS. I hope to be able to report on that soon.
2 topics in this article: carbon fiber, Ghostbuster
New Rotor harness
Mon, Mar 18 2002, 2:00:04 pm EST
carbon fiber|Larry Jorgensen|Paris Williams|Rhett Radford|Wallaby Ranch
Carlos Bessa from Wallaby Ranch just came back from the Nationals in Brazilwere he did very well and with a new harness from Nene Rotor. Carlos, after hearing about my tuck and fast descent rate, decided to fly with two parachutes. BTW, Paris Williams, who has had to throw his chute, also flies with two parachutes. Last time I checked, so did Larry Jorgensen, who also has thrown his chute. Do I detect a pattern here?
None-the-less, Carlos looks like a pregnant guppy with two chutes, but they conform very nicely when he tucks his elbows. His harness has white Mylar on the top and a new black material on the sides:
You’ll notice how smooth it is. Like the Moyes Matrix there are pockets in the inside of the sides that allow you to place you bags in there to contour the harness behind the parachutes.
Most of these side mounted harnesses have covered pockets on the side opposite the parachute. Carlos has his radio up inside in a pocket near his shoulder.
The back plate has been changed to widen out near the shoulders and the ends of the back plate curve down to go around the shoulders. You’ll notice in the details shot that a zipper is used to close off the parachute pocket, similar to that used on the Moyes Matrix.
All the buckles are inside and the bottom buckle uses the Tenax system. The top buckle is padded on the inside.
Carlos was also using a specially designed speed bar shown here (just sitting on top of the regular base bar.)
Apparently a number of pilots in Brazilhave attempted to copy this design, but failed because they used only carbon fiber and not carbon and chrome moly steel. Rhett Radford designed and built this speed bar to allow Carlos to old the bar at his chest while racing into goal while other pilots had to hold the bar at their waists. The angles of the bar give him substantial side to side leverage.
5 topics in this article: carbon fiber, Larry Jorgensen, Paris Williams, Rhett Radford, Wallaby Ranch
Keeping Rigid Wings Cool & Strong
carbon fiber|Davis Straub|Florida|George Ferris|Ian Duncan|Jaime Ruiz|record|Wallaby Ranch
Jaime Ruiz «jaimeruiz111» writes:
Ian Duncan from Moyes wrote (OzReport.com/Ozv6n30.htm) that the hot Florida sun would bring rigid wing’s carbon fiber structures to over 160°F, even under the cover of your white sail. This temperature would weaken the epoxy in the carbon fiber corner tapes that the aeronautical designer Felix Ruhle recommended and I used to strengthen my Atos (OzReport.com/Ozv6n28.htm), Ian claims, rendering them useless. Given Ian’s ominous assertions, I decided to do some minimal research into epoxy Tg, and a quick and cheap, but effective test of temperature differentials inside the sails in the Florida sun.
Epoxy Tg
Tg, or the “glass transition temperature,” is the temperature (actually a temperature “range”) at which the cured epoxy will begin to significantly compromise its physical properties of consistency, hardness, shear strength, tension strength, compression strength, flexural strength, etc. Epoxies cured at room temperature have a maximum Tg of 60-65oC regardless of their hardener ratios, or up to 90oC with a post-cure at 60oC heat for 2 hours. To get an epoxy to develop a Tg over 90oC it needs to be cured for hours in a specially built high-heat oven. However, you can post-cure your resin structure with heat lamps under a tarp, or even expose just the black carbon tape to the hot sun for two hours the day after. This will increase the Tg when cured, and make the resin structure stronger.
Aircraft Spruce (877-477-7823) sells E-Z Poxy 83 or 84 with these characteristics. Epo-Tek (1-800-227-2201, www.epotek.com) makes and sells an epoxy (#301-2, $40/16 oz) for structural parts with a Tg of 194°F, a 3-1 resin-to-hardener ratio and an 8 hr pot life. This #301-2 epoxy cures in 2-3 days at room temperature. If you look hard and ask the right questions, you’ll find other good ones too.
Is unfortunate that Ian Duncan did not share with us the epoxy name that Moyes uses, its physical characteristics, Tg cure temperature or technique, cost, or distributor’s name. Ian also forgot to mention that the curing of epoxy carbon fiber parts with a professionally heated oven is a technique only available to manufacturers due to its high cost. Manufacturers have the clams to buy expensive ovens and cure many parts simultaneously, bringing their curing cost-per-unit down. The high cost to buy an oven or make a single cure is totally prohibitive at this time for individual rigid wing owners. My simple room temperature resin cure imitated the home brewed “manufacturing conditions” that individual rigid-wing owners would use to strengthen their D-spars, should they choose to do so. That was the practical reason for using a room temperature cure on my carbon fiber corner tapes.
Sun Heat Experiment:
I got three round 6” diameter outside-thermometers from Wal Mart ($3 each), set up my Atos, and taped one thermometer to each wing D-spar, inside the sail, between the 4th and 5th ribs. (Note the spoiler wire in front of the thermometer.) The third thermometer I kept for outside temperature readings in the shade under a wing. I left the left wing with the standard sail for comparison purposes (and because I was also tuning the spoiler cord, replacing a fish cam, etc.). But I covered the right wing sail top with Energy Shield 200, a heat reflective, silver laminated fabric, manufactured and sold by Bruin Plastics (1-800-5566-7764). (I bought ES back in October of 2001, when I still had Davis Straub’s older Atos, realizing the need to protect the black carbon fiber of my Atos from high temperatures when out in the sun.)
Energy Shield
ES is a waterproof, highly reflective, silver laminated thermal barrier, 10 oz/sqyd fabric used for airplane windshield covers to reflect radiated heat out and keep the instruments cooler inside the cockpit; for pizza bags to reflect heat in and keep the pizzas hot for delivery (next time you order a pizza for delivery that’s the material in the bag), and for many other thermal barrier uses. It is made by BRUIN PLASTICS (1-800-556-7764) who also sells directly to the public. (If asked, some pilots may want to state that their purpose is to cover an airplane windshield, since I have been told that Bruin might be reluctant to sell to hang glider owners for liability reasons.)
With the Energy Shield cover I protect my Atos from the sun and rain when left in the open for several days at Wallaby Ranch or elsewhere. This stuff reflects light and heat so much that you literally cannot look at it straight when out in the sun. Looking at ES is almost like looking at the sun reflecting on a mirror, forcing you to squint and look elsewhere presto. I bought 25 yd (54” wide) for $175, cut about 14 yd for both wings, and in half-hour made two wing top covers with nothing but sticky-back Velcro from Home Depot, scissors, and a measuring tape. (You can cover two Atos with 25 yd. But a full roll has 100 yd and they wouldn’t sell me less than 25 yd.) Since the Velcro snaps on and off very fast, these wing covers are very easy to use and convenient. I left the bottom of the wings open so that the air would move under the wing instead of accumulating hot air inside, heating the carbon fiber not only by radiation but also by convection. (I used 7 more yd of ES and some Velcro tapes to make a cocoon or sock for my Atos in its wooden cradle when transporting it on my car roof.)
Data Results:
On March 8th, after having the Atos out in the Florida sun for two hours, these were the recorded temperatures at3 pm in the afternoon Florida sun:
Shaded Outside Air Temperature | 82°F |
Inside Atos Wing | 93°F |
Inside Atos Wing W/energy Shield | 87°F |
Temperature Differential | 5°F |
(Unfortunately the testing conditions were not perfect since it is March, the air temperature is relatively cool, and not July-August, the peak of theFlorida heat. But, like most instances in life, you do the best you can with what you have.) As you see, the Energy Shield cut the heat above the air temperature on the standard wing to about half. One can reasonably infer that this temperature differential will grow as the outside temperature increases in the summer, but that remains to be tested again in a hot summer day. A temperature differential of up to 25oF cooler (under the Energy Shield) in the summer months is realistic. Testing again in the hotter more vertical sun of the summer would give us data closer to the worst heat conditions, but the conclusions should remain the same.
Conclusions:
1) Energy Shield, a silver laminated reflective heat barrier, is very effective in keeping the carbon fiber protected from the sun’s rays, and is particularly useful when you leave your rigid wing out during the hot summer days in areas likeAustralia,Florida, the Owens’s Valley, and Zapata, Texas.
2) Using such thermal barrier while standing under the sun, and taking it off just prior to takeoff, will keep your carbon fiber D-spar as cool as possible. (Try not to place your rigid on a heat reflective surface such as asphalt or concrete because you will also increase the heat below the wing due to reflected radiation. When possible, grass is best.) Using this thermal barrier virtually guarantees that the structural integrity of your D-spar—and, in my case, the epoxy and carbon fiber corner tapes—will remain relatively cool, strong and effective, regardless of the sun’s heat rays above.
3) You may find other competitive reflective laminates such as Bruce Custom Covers, but they are very expensive and don’t sell the material by itself, only the end product. At Wallaby Ranch, George Ferris has built Atos covers and sells them, although I don’t know the properties of the material. (I don’t sell wing covers.)
If you fly a rigid wing, please consider using a tree shade if available, and a highly reflective laminated thermal barrier to cover your wings always, especially in the summer months.
Ian further stated that “Strengthen the spars along their length only and you apply more load at the center junction. Something may still give as you have increased the stiffness and therefore the shock loading.” If the corner tapes shift the loads from the weaker to the stronger structural sections of the glider, then we have certainly succeeded. I am not, nor do I claim to be, an aeronautical engineer or designer, but Felix Ruhle is and very successful at it. Felix’ reinforcing corner tapes have not only a vertical component to strengthen the D-spar against up-down (pos-neg Gs) loads, but also a horizontal component at 90° to the vertical section of the spar. This horizontal component increases the resistance against the drag as well as torsion forces. Therefore, contrary to what some have said, Felix tapes strengthen the D-spar in all four dimensions.
All gliders have a breaking point, no matter how much overly-designed. “Something may still give…” is always true. That statement confuses, and doesn’t add any value. However, the carbon fiber corner tapes that Felix Ruhle recommended to strengthen my Atos-c (OzReport.com/Ozv6n28.htm) does significantly raise the G loads—negative, positive, drag, or torsion—needed to break the D-spars at their proven and most vulnerable breaking points… with a minimum added weight. This is a structural fact of significant safety value given freely only for your evaluation and well being, without any competing, self-serving, commercial purpose or conflict of interest on my part. Could such post-manufacturing room temperature epoxy cure and carbon fiber strengthening of the D-spars be improved and made cheaper, faster, lighter, stronger, less susceptible to summer heat and generally speaking better through improved design and more sophisticated manufacturing techniques? Yes, of course.
Aeronautical designers face a challenging balancing act—the most strength for the least weight, or the most bang for their buck, if you will. They also want to constantly improve their original designs as more and better data surfaces with the hundreds of rigid wings flying out there. Designers are inventors at heart. Constant improvement with newer and better prototypes is the name of their game. Look at A-I-R web site and you will see the “constant improvement” or Kaizen philosophy that Felix built into its corporate mission. I am sure that the rigid wings sold three years from now will be stronger, faster, safer, and better than today’s. We, as pilots, can add value to the process and accelerate its improvement rate by giving valuable data, ideas, and feedback to the designers. But… are we not to take improvement steps today because tomorrow will (always) bring us a better hindsight, or someone else will eventually do it better? Oh, come on!! Fear not but fear itself.
Discuss "Keeping Rigid Wings Cool & Strong" at the Oz Report forum link» »
8 topics in this article: carbon fiber, Davis Straub, Florida, George Ferris, Ian Duncan, Jaime Ruiz, record, Wallaby Ranch
Sparrowhawk »
Tue, Feb 19 2002, 4:00:00 pm EST
carbon fiber|Greg Cole|sailplane
carbon fiber|Greg Cole|John "Ole" Olson|sailplane
(?-i)John "Ole" Olson|carbon fiber|Greg Cole|sailplane
carbon fiber|Greg Cole|John "Ole" Olson|sailplane
I sent a few questions to Greg Cole, principal in the company manufacturing the SparrowHawk, «cole» who writes:
The SparrowHawk uses HT grade Divinycell foam. In my opinion this is the best foam available. Please note that this is an aerospace grade of foam and has a very high temperature operational limit and toughness that exceeds all other foams.
The carbon fiber fabric used is special, but is not unique to the SparrowHawk. I have been aware of this fabric for many years through its development cycle. It offers many performance advantages over more conventional fabric. It is true that the SparrowHawk is the first aircraft to fly using this material. Again, this is a high quality aerospace grade material.
We have quoted conservative minimum sink numbers and definitely expect to better them. We have already demonstrated better performance.
By the way we have been to 120 KTS, 9300 FT, and have flights of over 3-hrs duration in the winter. The SparrowHawk climbs and runs very, very well.
The SparrowHawk is very strong. The first aircraft has been tested to limit load before flight testing, and these limit loads exceed those of most sailplanes. Our limits are +5.5 and -4.0 g's with a rough air and maneuvering speed limit of 80 kts. The SparrowHawk is the only light sailplane that I would take into conditions were strong rotors may be encountered.
We have 45 to 45 deg roll response times of 2.7 seconds. This exceeds the roll response of any sailplane I have heard about. Coupled with the high load limits and high-speed capability the SparrowHawk will be as good or better than even the most current generation of modern sailplanes of any size.
You also mention the BRS. This is an option in the SparrowHawk.
http://www.windward-performance.com
3 topics in this article: carbon fiber, Greg Cole, sailplane
Carbon fiber work
carbon fiber|Ian Duncan|Jamie Shelden
There was significant response to Jamie Ruiz’s article on beefing up the ATOS. Many pilots with extensive carbon fiber experience had lots to say about Jaime’s methods. I’m afraid that there wasn’t any mutually agreed upon resolution. You can find some of the correspondence on the rigid wing list, which often serves as an adjunct to the Oz Report.
Ian Duncan <compositecreations@bigpond.com> who makes the Moyes Litespeed carbon fiber spars and who has lots of concerns about the curing temperature of composites and how hot these spars get in the hot Australian sun writes:
Just thought I'd point out that Jaime's repair as stated by himself was carried out with a 2:1 epoxy mix… with a Tg of say… 60°C. On a hot day in Florida, given some temperature inertia in the Atos spars, these additions would be all but useless straight after takeoff until the resin cooled. Then repeat the cycle over and over again and before long its always useless. I have sent Jaime an e-mail but thought it prudent to point this out to you in case you thought to follow his instructions… on how not to do a repair.
The Tg is the temperature at which the cured epoxy will resoften. All cured epoxies soften eventually at some temperature. The cure 2:1 systems soften at around 60°C. Black carbonfibre can get up over 100°C in the sun. Even under the cover of your sail the spars can get up around 80°C. At this temp. all your additions are in a soft resin matrix and doing nothing. Think about the consequences of the cycling of softening and hardening and what it will do to your beautiful job especially if there is any movement of the original Atos spar whilst your repairs are soft. Ask your resin supplier what the Tg of your cured resin is!
When we first built carbon spars for Moyes CSX they were quite large diameter and therefore quite stiff. We thought this was great until you think of a pilot tumbling around under a glider or being slammed into the keel in a tuck… Karate Kid with a whole body weight as a fist.
The Litespeed has been subsequently built with spars that flex to smooth out the impact loads. A combination of strength and flex. The Litespeed spars will bend 4 feet before failure.
Apply this theory to an Atos wing with such a deep chord and such a thin laminate and it is not so surprising that the spars will fail under the shock loads of a tumble/tuck. Strengthen the spars along their length only and you apply more load at the centre junction. Something may still give as you have increased the stiffness and therefore the shock loading.
Discuss "Carbon fiber work" at the Oz Report forum link»
3 topics in this article: carbon fiber, Ian Duncan, Jamie Shelden
500 probes (Luft Balloons?)
Exxtacy|Ghostbuster|Millennium|Steven "Steve" Pearson
Steve Pearson mentions that it takes about 500 gliders to be produced, sold and out there flying until we really have any idea of how they will do with respect to tucking, etc. Well, let’s take a very preliminary stab at seeing how things are going.
Topless flex wings:
> 500 units
spins: seem to be as difficult to spin as previous flex wings
tucks/tumbles: a small number of tucks, less than advanced king posted hang gliders, at least one death.
Millenniums:
50 units
spins : very easy to spin, almost all have spun, some into the ground with injuries and one death
tucks/tumbles: no tucks or tumbles know to me.
Swifts:
Small number of units
spins: a small number of spins into the ground with injuries
tucks/tumbles: no known to me.
E7/Esc:
< 50
spins: easy to spin, although less so than the Millennium
tucks/tumbles: no known to me
Exxtacy:
400-500 units
spins: difficult to spin because of the forward placement of the control bar although has been done intentionally (similar to flex wings), very violent spin when entered.
Tucks/tumbles: no known to me.
Ghostbuster:
< 100
spins: a few. Easy to spin if hang point put way at the back and heavy pilot. New wires place control bar forward like Exxtacy to prevent spins.
Tucks/tumbles: a few with the leading edges destroyed in tuck and tumbles
ATOS/ATOS-C
400-500
spins: spins when pilot places hang point at the back of the range and flies slowly, otherwise difficult to spin. A few pilots have spun into the ground, a couple of deaths
tucks/tumbles: a few with the leading edges destroyed.
Top Secret
< 50
Spins: spins easily, at least one into the ground with one death
Tucks/tumbles: none known to me.
Any corrections or updates to this very preliminary chart are appreciated.
Discuss "500 probes (Luft Balloons?)" at the Oz Report forum link»
4 topics in this article: Exxtacy, Ghostbuster, Millennium, Steven "Steve" Pearson
Tuck issues
Gary Valle|Mike Meier|Steve Elkins|Steven "Steve" Pearson|Tom Price|USHGA BOD
I had an opportunity to speak with Steve Pearson the designer at Wills Wing at the recent USHGA BOD meeting. I've had a number of opportunities to speak with Steve over the last few years and I always find my time well spent and I come away enlightened about a particular issue.
Steve pointed out that a great deal of relatively sophisticated analysis of hang glider and flying wing stability was done as much as 25 or more years ago, and that this analysis is applicable to any current concerns about tucking or tumbling, and should serve as a starting point in any attempt to develop theories about our current problems in this area. In particular we should review articles by Gary Valle, Tom Price, Hewitt Phillips, R.T.Jones who have contributed immensely to our understanding of this phenomenon.
Steve said that in the past Mike Meier had conducted a survey of hang glider tucks and tumbles in an effort to determine if there were common design or test result factors that could explain them and help hang glider designers overcome the problems. Within the class of high performance gliders, the data did not seem to indicate any correlation between design factors or test results and tumble frequency, and thus didn't provide much guidance to designers.
Recently it seems that a change may have occurred. Second generation and later topless flex wings seem, in recent years, to have a better record with respect to tucks and tumbles than the previous generations of advanced king posted hang gliders. It's difficult to quantify this, because in the history of the sport there have been periods of time when tumbles have been more or less frequent, without any obvious changes in design.
Steve wasn't confident that he had a good explanation for the apparent recent improvement in the record of topless gliders. On the other hand, he thought that the improved safety record might be related to a maintenance issue with king posted gliders and reflex lines.
Both Wills Wing and Bautec had earlier found that when the trailing edges of the sails shrink as they do over time, the reflex lines get loose and don't provide for reflex for dive recovery. When they tested older HP gliders their pitch stability was terrible.
There is both a report and a service bulletin posted on the Wills Wing web site http://www.willswing.com/launch.asp?theCategory=support&link=frmSupportPage.asp 'Reflex Bridle Adjustment and Maintaining Pitch Stability' It might be the case that the topless glider is more likely to stay within its design specifications because the reflex provided by the sprogs doesn't change as the sail shrinks. The same design factor is inherent in the design of rigid wing hang gliders.
One king posted glider for which Wills Wing has no record of any tucks or tumbles is the WW Falcon. Pilots generally think of this class of low aspect ratio glider as not being subject to tumbling, however, in the mid seventies tumbling was a serious problem on a wide range of gliders with very similar aspect ratios. What is interesting, however, is that the Falcon has relatively weak stability on the test vehicle at high speeds in comparison to either a topless flex wing or, presumably, a rigid wing (though it has similar, and perhaps better stability at low speeds).
Based on the safety record of the Falcon, Steve thinks that it's probably reasonable to conclude that other factors like pitch damping and stall behavior may be as important as pitching moment to overall glider stability. He said that vehicle and flight tests of a tail attached to a flex wing glider at Wills Wing indicated that it did not necessarily represent an easy way to improve the pitch stability of a flex wing without incurring other compromises. He felt that these test results would not necessarily be applicable to rigid wing hang gliders with their higher aspect ratios and consequentially lower downwash near the root.
He felt that tails that were attached right to the keel would be less effective, as they would be in the downwash, compared to tails that were T-tails and raised up above the keel and further away from the downwash. Steve said that the increased pitching damping contribution from the tail may be equally as important as the increased stability coefficients, i.e. slowing the rate of rotation.
He also stated that theory and speculation are not adequate to predict with confidence the statistical incidence of pitch-overs and tucks of a given model. (For example, compare the safety record of the Exxtacy to the Atos). He also pointed out that it is known that many flex wing gliders are considerably stronger than they need to be at a minimum to pass HGMA and DHV certification and that the carbon fiber cross tubes/spars on topless flex wing gliders appear to be much more durable and damage resistant than the carbon fiber d-cells that are found on rigid wings. (BTW, WW static tests each of their carbon fiber spars. 1 in 100 fails with no obvious flaw.)
Rigid wings, both because they are more rigid and because they are capable of accelerating very quickly to very high speeds, may offer a reduced structural margin in extreme circumstances. Steve pointed out the HGMA uses a 150° load test (basically you attach the glider to the truck with its back into the wind and tail down 30° and run it up to 32 mph). The DHV doesn't use this test.
The test is designed to simulate the loading that would be experienced after 180° of pitch down rotation during a tumble, which has been the more common issue of concern, at least with the HGMA, over the last 25 years. (The test does not simulate the loading in a tuck, which typically happens at a much higher speed). Since none of the rigid wings certified so far have been certified to he HGMA standards, it's not clear how they would perform in this test.
Finally, he stated that it is likely that any hang glider would be destroyed in an accelerated, high speed tuck, one like mine. He felt that at very high speed, the wings could fail without significant negative loading from torsion and drag loads alone. He felt that it was unlikely that my glider actually experienced a significant negative load during the event, because I had reported that the glider apparently failed before I hit the keel.
Without the mass of the pilot "attached" to the center of the glider, any positive or negative aerodynamic loads would be expected to be distributed over the structure relatively evenly, in such a way that it is unlikely there would be a high enough load to cause a failure.
Steve Pearson wasn’t the only one who was thinking about tucks. Steve Elkins writes:
In my 12 years of being involved with the pitch testing of hang gliders, neither I nor anyone else involved in UK pitch testing has ever seen, or heard, of a hang glider with suspect pitch stability (i.e. one that has tumbled or otherwise given rise to stability concerns) that has subsequently passed the pitch test.
Of course, given Felix’s tests at DHV of the ATOS-C, it looks like this is a first for Steve. He also writes:
However if you are flying a glider with a C of A that is within spec, there's no evidence that you need to rush out and fit a tailplane.
Seems like a lot of things are up in the air.
Another writer sends this in:
I have no axe to grind about tailplanes, but have always been aware that as we fly gliders with higher aspect ratio, hence narrower chord for a given area, we must be more prone to tucking and tumbling (I am an engineer, but not a hang glider or sailplane designer or anything like it, so its slightly more than just a gut feel)) and we put our trust in the designers of our aircraft and the test procedures for making sure that they are safe.
To be a bit more technical, again Martin Jursa, "The essential parameter determining the tumbling ability is the ratio between mean chord/Center of Gravity depth, the smaller this ratio …the easier the glider will go upside down.” It’s obvious from this that for a given wing area a glider with an aspect ratio of 12 to 1 will have about a 20% disadvantage over one with a 7.6 to 1 for the same Center of Gravity distance.
Moving on to the C of G issue, we need to explain what needs to happen when the glider's AoA suddenly becomes negative. The gist of it is that the addition of the pilots weight moves the gliders C of G downwards, this improves the stability of the glider from the test rig certification values at positive angles of attack, but worsens it at negative angles of attack particularly in the -5 to -10 ° area.
The more forward the pilot can move his weight under these conditions the smaller the adverse effect becomes until, if sufficiently far forward,the glider won't tuck or tumble. Hence the importance of being able to hold onto the bar and getting into the safety position. On stable gliders it is only necessary to pull in a little to achieve this, on more marginal machines pull in more!, but to do this you must keep hold of the bar and so on.
What I can see coming out as a result of your incident and the statement by AIR that the glider was within "DHV as tested specification", which is what I construe them publishing the inspectors report is meant to imply, is that the testing criteria used by our sport to regulate the safety of our gliders is suspect. It may be adequate for tailless gliders of a certain configuration (what are the limits) but those that fall outside this probably require extra study.
Bjørnar Ryeng <bjornar@intime.no> writes:
Also gliders (sailplanes) can definitely go inverted in strong turbulent air. I was almost inverted in an old K8 when I was relatively new to the gliding and going for some waves in strong headwind (ehh… Relatively strong - I was flying a K8). The glider recovered through a "half loop" from some 20° past vertical. If it had continued I would have pushed carefully and rolled it back from inverted instead. Except from a lot of sand and shit in my eyes and hair I was fine.
Discuss "Tuck issues" at the Oz Report forum link»
6 topics in this article: Gary Valle, Mike Meier, Steve Elkins, Steven "Steve" Pearson, Tom Price, USHGA BOD
Icaro 2000⁣’s new ATOS-X »
carbon fiber|Icaro 2000|Wills Wing
You can find out more about the rigid wing offered by Icaro at http://www.Icaro2000.com/Products/Rigid%20Wings/Icaro/Rigid%20Icaro.htm.
After a review of the new pictures of the new version of the ATOS from Icaro it is clear that it is the ATOS-C without Felix's new control frame but with the Wills Wing ATOS control frame instead.
I love both control frames after having flown extensively with both of them.The WW will control frame will be less costly for the pilot and allow for quick replacement of the down tubes.
The AIR control frame has stainless steel tubes that act as weaklinks in the carbon fiber downtubes.Pilots will instead of replacing downtubes will replace these weaklinks when they have poor landings.The AIR control frame is extremely strong (having survived quite a bad landing and for the most part survived the destruction of the ATOS in the air), but it is not as standard nor are it's parts as easily replaceable as the WW control frame.
I think that the AIR control frame should provide a very slightly better glide than the WW Control Frame.My results with the ATOS-C indicate that it provides the extra performance that I desired but now much was due to the AIR control frame over the WW control frame is unclear.
Discuss "Icaro 2000⁣’s new ATOS-X" at the Oz Report forum link»
3 topics in this article: carbon fiber, Icaro 2000, Wills Wing
Scatter in the drop test data
Angelo Crapanzano|parachute|Rob Kells
I had an opportunity to speak with Rob Kells about parachutes at the recent USHGA BOD meeting. Rob admitted to the fact that Wills Wing hasn’t done a good job getting out useful information to pilots to help them pick a parachute of an appropriate size. One problem he mentioned was that there was a wide scatter in the drop test data, the results of tests that determine the rate of fall under various loads.
He has decided that it would be a good idea to publish all the data so that pilots can see just how wide a variation there is in manufacturer’s tests when they report how well their parachutes due.
What should pilots be interested in? For one thing, they will want to know just how fast they will be coming down (given their weight and a portion of the glider’s weight) and how that value relates to their chance to suffer from injury. Of course, if you’re going down under canopy in 500 fpm sink, it’s going to hurt a bit more.
Angelo Crapanzano has presented some strong arguments for his position of chute size and I look forward to hearing more from Rob.
Discuss "Scatter in the drop test data" at the Oz Report forum link»
3 topics in this article: Angelo Crapanzano, parachute, Rob Kells
Twisting your life away
Mon, Jan 28 2002, 5:00:04 pm EST
carbon fiber
While lots of exciting incidents occurred during the Bogong Cup, some of the most exciting were incidents that didn't occur because some folks were sharp eyed enough to spot a problem that was about to happen. Twice different folks spotted side wires that had almost all their strands broken.
The first non-incident occurred on launch at Mt. Buffalo. It's quite a spectacular launch and a long ways down if your wings fold up. Paul the launch marshal noticed that the strands next to the nico at the bottom of a side wire were frayed. Turned out that sixteen of the 19 wires on a 1 by 19 2-mm side wire were broken at the nico.
This was on a pristine looking Moyes CSX. These wires are now in common use and Moyes uses standard methods and fittings, so it is not a reflection on Moyes in particular that it was a glider than they had manufactured.
1x19 wire is more commonly used today than previously. A 2mm 1x19 wire should be able to hold 450 kilograms. A 2mm 7x7 should be able to hold 400 kg. A 7x7 2.5-mm wire should be able to hold 900 kg.
On topless gliders the cross bars without the side wires are supposed to be able to handle 3 g's. The typical force on the side wires would be about 140 pounds. The 3 remaining strands of wire would just about hold that amount of force.
The next non-incident occurred on the last day of the Bogong Cup when a pilot noticed one strand of a side wire was frayed. When the plastic coating was cut back from the nico it was found that a total of fifteen of the wires were broke. That left four wires and the carbon fiber spar to hold the positive load on this Moyes Litespeed.
The glider was one year old and had about 120 hours on it.
In both cases the wire was 2 mm 1x19 stainless steel wire. In both cases the wires were broken at the nico. At least in one case it was not possible to fully inspect the damage without removing a plastic coating.
Perhaps 1x19 wires should be inspected frequently. Perhaps they are less flexible than we think.
1 topic in this article: carbon fiber
Mark wants to know
Mon, Jan 21 2002, 1:00:03 am EST
carbon fiber|Rohan Taylor
carbon fiber|Oleg Bondarchuk|Rohan Taylor
carbon fiber|Oleg Bondarchuk|Rohan Taylor
Mark Mullholland «MarkMulhol» (can't keep a good man down) writes in in response to my comments about the Australian Nationals.
Can you enlighten us about the drag configuration of each top pilot?
My Response:
What I really need here are some pictures. I know that many of you want more of them, and I'm always remiss in not taking more and publishing more of them.
The top flex wing pilots are flying in very streamlined harnesses and with airfoil control frames and thin wires. The new Moyes harness looks great, as does the new Aeros harness than Oleg is doing so well in. Gerolf continues with his M2 Cigar harness.
I'm flying in my Center of Gravity Carbon Fiber harness, which I love (because it is so comfortable) and find is very streamlined. Rohan is flying a very visible purple Skorpion harness from Dynamic Flight.
Again, I wish I had taken more pictures. Many pilots got to try on different harnesses (one breaking Conrad's zipper) during the days that we didn't fly in Hay. Paris is flying the MR Tenax with two parachutes (looks like he's about to have twins coming out the sides).
All the top pilots have to fly with the least drag producing harnesses and control frames. Round base tubes, wheels, old harnesses (like Bo's), thicker wires, kludgy hang straps, etc., mean that you won't be in the running for the top spot. Differences in drag are a big part of the differences in performance between pilots.
Mark writes:
I believe that the gliders are very similar, and that better performance is achieved by reducing drag. Hence harness type, and instrument drag are a HUGE portion of the potential L/D performance of a flex wing. Please let your readers know what the top pilots are using.
My Response:
The flex wing gliders are very similar (say more similar to each other than they are to the rigid wings or to the Swift Lite). Top pilots spend significant efforts on drag reduction. All top pilots use faired instrument pods.
Mark writes:
What configuration was the Swift in? How much fairing did it have?
My Response:
The Swift Lite was fully faired for both meets.
Mark writes:
Why did you win, if the Swift "obviously has better performance"?
My Response:
Much more experience. I just have a lot more experience than Bruno in flying in the Australian competitions.
Launching earlier. I think Bruno may have been obligated to launch last or near last given his configuration. Maybe he didn't want to get in the way of flex wing in line. I didn't quite understand the situation for him or his reasons.
Starting late is not that bad of an idea especially if you have overwhelming performance superiority as you can much more easily take advantage of the slower pilots out in front of you marking the thermals. On days one and four Bruno was able to start late and use the pilots in front of him to have very fast times.
My earlier start on day one made up for my slower times, so that I was not too far behind him after the first day. On the second day with our out and return task with a strong cross wind, Bruno started only 15 minutes behind the main gaggle. I was able to fly a little bit faster than him and given my earlier start time and arrival, get back into the lead.
On day three Bruno had a good time, much faster than me, but not an outstanding time. He started 45 minutes after me and 15 minutes after the main gaggle. His late start cost him departure and arrival points.
On day four, Bruno started a half hour after me with the main gaggle but flew very fast. He came in just three minutes after I crossed goal. His time was 17 minutes less than anyone else. He was now only thirty points behind me and in a very good position to win the Australian Nationals overall.
On the final day, Bruno started with the main gaggle at 2 PM. This is the first day that I got to see more than a glimpse of him flying in the air, in fact he flew right below me by a few feet at one point.
One the flight out (downwind) to the first and second turnpoints Bruno appeared to fly pretty much by himself. I got to see him low and flying fast searching all around for thermals. He appeared to cover about four times the distance that any of the rest of us covered getting to Booligal.
On the way back Bruno hooked up with the main leading gaggle about half way back to the third turnpoint at One Tree. He was back up with the rest of us now and not getting too far away. I got low soon after this point but I saw him reasonably high a few kilometers in front of the gaggle heading for the third turnpoint.
After making the third turnpoint I head a little cross wind toward goal and when I got down to 1,500' 30 kilometers from goal I spied Bruno in what now from my perspective looked like a "space ship." He was way up there, way over my head, and slowly climbing presumably in the same lift that I had found.
He continued to stay in this thermal for a long time. We were both way out in front of the flex wing gaggle, both alone, far apart in height.
I got up high at this point when Oleg caught up with me and showed me a strong core just a little ways behind me. Bruno, from his very high perch, continued on toward goal. I thought at that point that the contest was over and that he would be gliding into goal from 8,000' thirty kilometers out.
As Oleg and I pressed forward after getting high, we saw Bruno on the deck (600') at twenty kilometers out. He was in a struggle just to stay up. He had lost an incredible amount of height in just 10 kilometers.
I was now far over his head and he was preoccupied with survival. I felt that I now had a chance to win the meet overall.
I took my time forging ahead and finding lift to stay high enough to make goal. On that day I beat him by 33 minutes getting more departure, speed and arrival points.
Bruno's strong performance advantage both worked in his favor and against him. When it got him out on his own he sometimes struggled as on the last day. It only took one bad sink street to keep him in second place.
2 topics in this article: carbon fiber, Rohan Taylor
AIR ATOS rack pads
AIR ATOS|carbon fiber
Felix included some carbon fiber backed neoprene foam pads with his ATOS which he sent to me to use in Australia. These pads look like curved harness backplates, about 18 inches long and as wide as the ATOS is when packed up.
Since any dents that we might get in the carbon fiber on an ATOS would most likely come from transporting it on the rack, these devices should be particularly effective in protecting the ATOS.
Discuss "AIR ATOS rack pads" at the Oz Report forum link»
2 topics in this article: AIR ATOS, carbon fiber
The sweetest ATOS yet
Fri, Dec 21 2001, 2:00:03 am EST
carbon fiber
Aeros Combat|carbon fiber
Aeros Combat|carbon fiber
Felix sent me a new ATOS –C to fly here in Australia and maybe it is the wonderful air that I always experience here at Stanwell Park, but it sure felt great and flew fast with little to no effort.. You can't tell if it is the conditions or the glider, but either it was the sweetest conditions I've ever had here or this glider is something special. Lots of times I've been beat up pretty good racing down the escarpment, but not this time.
I got to race with Bo (in an Aeros Combat 2) and Paris (in an Icaro Laminar MRx) pulling in and going as fast as they wanted to go. Often I was pulling away from them and climbing on them. What made it different to me was the ATOS-C felt comfortable at higher speeds.
I noticed that the sail wasn't as tight as would normally have expected. Perhaps it was the fact that it was cold in Germany when Felix test flew it (but I though Dacron shrinks in the warm air – but then moisture has the opposite effects).
It was easy to pull in and go fast. How fast, well I didn't have any instruments with me. This ease of going fast indicated to me reduced drag. The carbon fiber control frame without the nose wires appears to be responsible for the reduced drag.
Felix has also made so other changes to the sail. First, the tips have been extended to cover up the tip levers and all the associated strings. This cleans up the tip completely.
Second, there is a shear rib on the eighth rib. It is on the outside of the rib, so the fish cam has been reversed and you swing the rib into place from the inside..
Third, there appears to be some additional material on the outside panels at the trailing edge. Perhaps the trailing edge has a slightly different shape.
I thought from comments from other pilots that I might find in difficult to get use to the ATOS-C in the air. It seemed to handle easily and very similar to the ATOS. I was most pleased.
1 topic in this article: carbon fiber
Wills Wing's new aluminum faired base tube
Thu, Nov 15 2001, 4:00:01 pm EST
carbon fiber|Ken Howells|Steve Pearson|Wills Wing
This week, Ken Howells at Wills Wing (www.willswing.com) sent out an announcement of their new faired aluminum base tube that fits right in with their cool hardware and their Slipstream downtubes. Haven't seen something like this before I wanted to get some feeling from Steve Pearson if WW knew how well this base tube compared with their existing carbon fiber base tube. And, just how much reduction in drag we could expect. Here's what Steve had to stay.
Steve Pearson «Steve» writes:
Outside of the handgrip area, the carbon basetube has the same section and trip as the carbon downtubes that we tested in Stuttgart. As you may remember, those results showed less than 10-20% of the drag of a round tube (depending on Reynolds number and angle of attack). The handgrip area is thinner that a Finsterwalder type tube but it's untripped. I'm guessing that the total drag in the grip area is 70% of a round section. 24 inches of the 54 over all length are in the grip area. [(24 * .7) + (.2 * 30)]/54 = .42, so I'd say that the drag has to be less than 50% of a round tube.
Our wind tunnel tests showed that an untripped Slipstream carbon tube had very high drag values until high speeds (45 mph). The Freeman tube is a thicker, higher drag section than the Slipstream and is untripped. Interestingly (but consistent with analytical results) the Slipstream untripped tubes have slightly lower drag at high speeds (60 mph) than the tripped section. Speed gliders could sand off the trips for marginally better performance, however at speeds less than 45 they'd be taking a BIG performance hit.
We don't have wind tunnel results for the aluminum speedbar. It's a modified Slipstream (with trip) section with the rear edge truncated in a large radius for a nice grip. I think it's more comfortable than the carbon grip. Rob and I had a chance for a 3-mile performance comparison the other day--he was flying a non-Mylar Talon 160 with the aluminum straight base tube and I was on a Mylar Talon 140 with a standard carbon basetube. We grouped up with him 30 ft above and behind. It wasn't until 2 miles into the glide and I'd picked up the speed to 45 that he moved off to the side. Just considering the glider difference, I'd expected to see him fall away sooner so the aluminum basetube can't be hurting too much.
The aluminum basetube is completely interchangeable with the carbon basetube. Of course the corner brackets are completely different because they have to blend from the 3in cord Slipstream to the 1.9in cord basetube. If you continue to fly with the WW Atos bar, I could make an interchangeable aluminum basetube for you by adapting a set of the GB fittings that were originally designed for a straight Bautec tube.
4 topics in this article: carbon fiber, Ken Howells, Steve Pearson, Wills Wing
GB d-cell mods
Tue, Nov 13 2001, 12:00:01 pm EST
Belinda Boulter|carbon fiber|Ghostbuster|Ken Strong|Larry Jorgensen|Tryg Hoff
Steve Daleo «stevedaleo» writes:
I agree with your comment about not being able to separate the glider / pilot combination. We’ve been disappointed that no one has really flown a comp with a GB that’s been really optimized/streamlined as some of the ATOS’ have been. I think that has really biased the results.
As you’ve said before, the little things really matter at that level. My personal experience says that the differences are pretty slight. The D cell mod has made a very noticeable performance difference in the GB, mostly at higher speed.
The WW control frame is also a huge improvement. I had the opportunity to fly my unmodified demo side by side with Mark’s modified glider, which I had just completed. We were at Funston on a solid day and at 50 or so, wing tip to wing tip, I went from 100 feet above him to 50 ft below him in about 100 yards. I’d love to do the GB/ATOS comparison. If Quest doesn’t have a modified GB that’s really been done right (vacuum bagged) that makes a difference as well.
I spoke with Larry Jorgensen this weekend as Belinda and I visited with him and Tina. Larry spoke about how much his Ghostbuster was changed by the addition of a 4 inch wide strip of carbon fiber all the way down the leading edge of each d-cell. This keeps the d-cells from bending back at higher speeds and keeps the trailing edge taut when racing between thermals.
This modification has been incorporated in the newer Ghostbusters and Axxess.
He also mentioned that eyewitnesses to Tryg Hoff's ATOS tuck noted that the aluminum tubes at the tips failed during the tuck and therefore didn't provide any force that might have allowed the ATOS to come out of the tuck. Once the ATOS was on its back Tryg fell into the keel and broke the d-cells.
He also mentioned how strong the nose pins, rings and carbon fiber threads are on the ATOS and the IXBO (and by assumption on the Ghostbuster). He noted that they were still completely intact on Tryg's ATOS as well as on Ken Strong's IXBO after their respective accidents. Ken went in nose first from 500 feet.
6 topics in this article: Belinda Boulter, carbon fiber, Ghostbuster, Ken Strong, Larry Jorgensen, Tryg Hoff
Pilots speak out
Wed, Oct 10 2001, 2:00:04 pm EDT
carbon fiber|Davis Straub|Dennis Yeomans|Nick Kennedy|record|sailplane|USHGA
carbon fiber|Davis Straub|Dennis Yeomans|John "Ole" Olson|Nick Kennedy|record|sailplane|USHGA
(?-i)John "Ole" Olson|carbon fiber|Davis Straub|Dennis Yeomans|Nick Kennedy|record|sailplane|USHGA
carbon fiber|Davis Straub|Dennis Yeomans|John "Ole" Olson|Nick Kennedy|record|sailplane|Tracy Tillman|USHGA
Andrew Ainslie«andrew.ainslie»writes:
Thought I'd tell you why I went the other way, from sailplanes back to hang gliders. I feel that location can have a lot to do with which of the two sports makes more sense. I started hang gliding again after moving to Los Angeles because a) it's a LONG trip to my favorite sailplane operation (Caracole Soaring), b) the soaring season for sailplanes is pretty short, with a fairly tough transition for the last 60 miles coming home from the Owens to Caracole on many days, c) LA offers ridge sites, convergence sites, dependable Kagel and the Owens.
But another interesting aspect has cropped up. Because of a tragic accident earlier this year where a friend of mine died following a spin on approach in my glider (look up my old N number, N 55 VW at www.ntsb.org for details), I decided to take a break from sailplanes. I love them, and usually fly one or two nationals and a regionals every year, but this accident made me reconsider, and move back to a more social form of flying.
And boy, is hang gliding good for that! I flew the Owens on 3 weekends, and all 3 were thoroughly memorable. Waking up in a campground next to Mt. Whitney, having breakfast with a bunch of eager pilots, and the trepidation as we try to pick an optimal take-off time all make this a really fun, social type of flying. Contests can be brutal, tiring and unfriendly sometimes - not because the people are unfriendly, but because flying them is just so much work that time isn't left over for socializing much.
No doubt hang gliding contests are also tiring and less social, and no doubt sailplane camps can also be pleasurable and relaxing. But somehow the awe of the new has left sailplanes for me, and right now I get a whole lot more pleasure flying my hang glider 100 miles than my sailplane 380 - and I did both of those out of Lone Pine on Memorial weekend this year. The 100 miler was by far the more exhilarating flight.
I suppose it's all about variety and change. A change in either direction can be a lot of fun. Unfortunately not a lot of sailplane pilots can be convinced that running off a hill and using your feet as landing gear is all that fun, but I'm loving it! And I encourage hang glider pilots who are feeling a little burned out to give sailplanes a bash - it'll rekindle all the early magic that got you excited about flying in the first place. Whether it's the amazement of setting out on a flat 35:1 glide at 70 mph for the first time, or watching the vario peg at 1800 ft up in a ratty thermal in a hang glider that a sailplane could never core, they both have new discoveries for the jaundiced pilot.
J. Dennis Yeomans, DDS «jdyeomans» writes
Glad to see you are enjoying getting into gliders. Thanks for sharing it with us.
I've been flying gliders as long as I've been flying hang gliders, 25years, although not nearly as frequently. To me, soaring represents man's true quest for flight. We have all become addicted to the sensation of flying in constant harmony with the vagaries of the atmosphere, akin to surfing on a wave, instead of punching a hole through the "bumpy" sky behind a propeller.
Since the essence of soaring is response to the air, we hang glider pilots are fortunate to fly the most responsive soaring aircraft of all, and there-in lies our special pleasure. Coming from where you are, I predict that you will begin to enjoy the 103 more when solo. You will enjoy the 102 even more, as the smaller aircraft gives us the response we have become accustomed to. I have been interested for years in the very light, hybrid, soaring aircraft.
Have you checked out the Sparrowhawk at www.windward-performance.com? A full-on carbon fiber sailplane at 155 lbs! Very special prices on first runs.
My biggest problem is no place to fly out here. I am considering keeping something at Dillingham, Oahu, or in CA.
By the way, if you get a chance to stop over on Hawaii, Greg Pierson has gliders to fly, and he has Forberger's atol rig. You can get some great thermal and ridge flying at Dillingham in a 103, then put on your harness and get in a few hours of HG. He tows along the runway.
Be sure to fly the Super-Floater next time at Wallaby. It's about the most fun aircraft I have ever flown.
Geoff Loyns «geoffloyns», former record holding hang glider pilot and sailplane pilot here writes:
I agree with every point Nick Kennedy made about why ex hang glider pilots like me went to sailplanes. I still have 2 H.G. one a Laminar, which cost way over $5,500 and is now just taking up space. My sailplane, Discus cost $44,000 in June 1999 and is still worth much the same, it is fully insured even when being transported in its trailer.
One point Nick missed from his list of reasons to go to sailplanes is no driver required, this year I've had 63 flights flown every time I went to the airport, 210 hours. 40 xc's totaling 8,228 nautical miles and only failed to get home twice. Both times landing at Rossachi strip 20 miles E.S.E. of Minden and aero towed back. Cost about $60 both times taking off within half-hour of landing.
The comfort, convenience, challenge and adrenalin buzz of flying sailplanes is way better for me.
Tracy Tillman «Cloud9SA» writes:
Hang glider (and ultralight) manufacturing companies should take notice of the trend going on, as indicated by some of the recent comments you have received and posted from hang glider pilots now flying sailplanes. As the pilot population ages, hang gliding has become less convenient and more difficult for many of those pilots. The market for hang gliders has become smaller. Yet, companies are missing a potentially larger market. To survive, they may need to innovate to expand their customer base.
It seems that there is a need for a 3-axis joystick controlled ultralight sailplane, that has a flexible hang glider-type collapsible wing (i.e., Talon, Litespeed), with a seat and tail, that can be fully collapsed and safely transported on top of a car, without a trailer or box-like a flex wing hang glider.
Collapsible/flexible hang glider wings could probably have greater performance if they were configured for aerodynamic, rather than weight shift control. Also, the problem with many current ultralight sailplane designs is that they are a pain to disassemble and transport, for XC flights, as least relative to hang gliders.
Not only would this type of flex wing ultralight sailplane be attractive to some current hang glider pilots, but probably to some ultralight, sailplane, and private pilots as well.
ATOS for sale
ATOS|carbon fiber|record|Rhett Radford|Wills Wing
I'm getting an ATOS shipped to me directly in Australia for the competitions there, so mine is for sale. I can sell it now or next spring. If you want a very cool ATOS (especially with the Wills Wing control frame) and the heavier duty sail clothe. Contact me at «davis». With the WW control frame: $8,500. Without $8,000.
This is the ATOS that set the world record in Zapata – 407 miles. I got it new in the middle of April at Wallaby. It has the reinforced keel and one repair to the leading edge, done by the master of carbon fiber – Rhett Radford. The sail is in quite good shape.
The ATOS is in Minden, NV. I can deliver in California. Other spots across the southern part of the US in February. Or I can ship at the end of October.
Discuss "ATOS for sale" at the Oz Report forum link»
5 topics in this article: ATOS, carbon fiber, record, Rhett Radford, Wills Wing
Simplifying the complex
Sun, Aug 26 2001, 6:00:00 am EDT
carbon fiber|Florida|Jim Lee|Mark Poustinchian|Wills Wing
carbon fiber|Florida|Jim Lee|John "Ole" Olson|Mark Poustinchian|Wills Wing
(?-i)John "Ole" Olson|carbon fiber|Florida|Jim Lee|Mark Poustinchian|Wills Wing
carbon fiber|Florida|Jim Lee|John "Ole" Olson|Mark Poustinchian|Wills Wing
I've received a number of requests to reflect back on the Nationals and provide a critique of the flying that I saw there. Gerolf gave a little talk before the meet got going and as it confirmed once again a number of things that I've learned, spending so much time on the competition circuit, I am encouraged to provide my reflections.
You'll notice that the top two pilots in Class I are factory supported. If you are going to win, you've got to come with the best equipment. While this seems obvious, it means that ninety percent of the pilots who show up are there for fun, only. Pretty darn good equipment doesn't cut it, if your interest is winning.
The Triumph of the Insignificant – once you've got the best that you can purchase, you've got to make it the best by tweaking it in every way possible. Gerolf flies the same glider that Moyes sells, but then he has a whole list of things that he does to it to very very slightly improve its performance. He said that all the top pilots contact him to go through this list and he will go through it with them, but that he is getting tired of doing this for everyone who buys a new Litespeed. Still, contact him if you purchase a Moyes Litespeed.
You need a tight fitting (let me again stress that it has to be fitted for racing) streamlined harness. Come with anything else and you might as well paint a big red L on your forehead. Want a parachute on your chest? Stay home so you won't have to hear the laughs.
For years Jim Lee has been dominant with his carbon fiber harness. This is no longer the case. It has a much bigger cross sectional area than the newer cloth racing harnesses.
BTW, a couple of pilots at Hearne were complaining of significant pain in their arms and shoulders while flying. You have to adjust your harness and hang strap so that you don't experience any pain. If you are experiencing pain, don't be a man and live with it, fix the damn thing. I am completely pain free with my Carbon CG harness, and I wouldn't be able to fly over ten hours if that weren't the case. Just how good are you going to be at decision making if you are flying in pain?
Aerodynamically clean control frames have taken over completely. The Wills Wing and the new Moyes control frames are the ticket. It sure makes a difference on the ATOS and likely comes very close to the new ATOS control frame that eliminates the front wires. In fact, you could use the new ATOS version of the Wills Wing control frame with the no front wires set up.
If you're going to race in racing conditions like we've had for the last two years in Hearne, and in Florida, then you've got to bring ballast. Either be a big boy, or bulk up with lead weights (bags of pellets used for scuba diving). I carry a mere 22 pounds and others carry more. The topless and the rigid wing gliders won't wash out with the additional weight. All the top finishers in Class I (the only class where there is sufficient competition so that all this really matters) were flying with ballast.
The strategic advantage that one gets from having slightly superior performance relative to the other competitors is enormous. You can see everyone below you, can glide to where they are, and can watch them take different routes and evaluate which is better. Your mental state is much improved when you don't have to overcome performance inferiorities through superior skills or better decision making.
A hang gliding competition in Hearne is a race. You won't find the strongest conditions in terms of lift, but you will find a cloud filled sky that indicates where to find the next filling station. You'll also notice that the day dies early, around 6 PM. Get caught out on the course late, and you won't make it home.
You can't hang around in relatively weak lift. You've got to leave the lift when it slows down. Now on some days it just kept getting stronger the higher you got, so you want to stay with lift that is doing this, but unless you are in a world of hurt, leave lift when it slows down.
Time after time I got ahead of the pilots that I was momentarily with by just leaving the lift I was in and going to the next thermal. Repeatedly this would put me in the lead, and alone, but it just didn't matter as the clouds were out there showing me the way.
Launch early. It is easy to stay up in the air at Hearne and the lift is so mellow that there is no reason not to be in the air right away and out of the heat. Now you've got a strategic advantage because you are up over your competition or at least close to them at cloud base. You can see if they are going to leave early or where they are finding lift. The race has begun an hour before the start times begin.
Unless conditions are deteriorating or it looks like you will be on the course as the day ends, take the last start gate. The early bird points just aren't worth any additional risk you may encounter. If it is a long task, like the day we did the 105-mile triangle, then the earlier the better. Lots of other pilots will be going with you.
If you are out in front, look around and see if there is help when you need it. Mark Poustinchian was leading the gaggle of rigids and flexies when we go on a 15-mile glide. He's in a very vulnerable position, as he has no one to help him as we go through the blue.
I'm off to his left getting closer and closer (ballast and the WW control frame). Robin is also off to his left but passing both of us high. Mark just doesn't look up and look around. He never sees me even though he takes a couple of turns in lift that doesn’t work out. If he had just looked back every now and then he would have had a chance to see me at 1,300' when I hit a spot of lift and he kept gliding only to land a few minutes later.
No matter what it looks like, if conditions get weak you've got to slow down. I sure wish I could learn this lesson. On the last day the conditions on the second leg are much much weaker then anything we encountered on the first leg, or at any time during the meet. Only a few pilots will make goal because of this because they don't slow down and take whatever they can.
There are plenty of clouds on the second leg, but they aren't working. There are high clouds shading the ground and most of the clouds are just the remnants of clouds that were working before the high clouds came over. We were racing so fast on the first leg that it is hard to slow down for the second leg.
On the last day I was watching Bruce as the only guy who could challenge me for third place (oh the joy) behind the space ships. He wanted to get off early and get the first start time. I could see that the day had a chance of deteriorating with high clouds. I could see how anxious he was and that he was definitely going to get going early.
I got up with him above the field and then watched as he headed out to the start circle far in advance of the first start time. This was smart for him because he needed to take a big chance if he was going to beat me. I felt that it wasn't smart of me, as I had beaten him the last two times by starting later and I didn't need the additional risk.
This proved to be the case as four rigid wing gliders that took the last start time were able to catch Bruce at the turnpoint 18 miles out in spite of his half-hour lead. Unfortunately that fast time encourages me to race on the second leg, while Bruce is used to the difficulty of the first leg and is more cautious.
Superior equipment and therefore superior performance, makes for superior skills and superior decision making. The differences in performance are exceeding small, but they make all the difference. It’s not about out flying 90 percent of the field, it's out flying the top one percent.
5 topics in this article: carbon fiber, Florida, Jim Lee, Mark Poustinchian, Wills Wing
ATOS with Wills Wing control frame
Thu, Aug 9 2001, 4:00:00 pm EDT
carbon fiber|Wills Wing
Ok, I just put it on and I previously had a control frame with WW slipstream (aluminum) down tubes, but I must say that I'm very happy right now. It looks so cool that I'm sure I will be going even faster. J
First off, the control frame comes with new and thinner (5/32" or 2 mm) front and back wires (and nose plate catch) – the standard thickness used on WW competition gliders. The ATOS comes with two wires that are continuous front to back. The WW control frame comes with four wires. There is a junction at the bottom of the down tubes. I really like the thinner wires – like I had before on my previous ATOS.
You use your existing side wires and connect them into standard small u-shaped brackets on the WW bottom joints. You just take off your old frame and wires and put the new WW control frame on. You can check your spoilerons to make sure that they are operating as you desire. If not, you can adjust the ropes inside the wings that control the amount of movement in the side wires.
Wills never optimized their carbon fiber base tube. The hand grip area is a bit too wide for my taste (I love my Aeros base tube), but I'm willing to make that small sacrifice. I will have to lay up some micro skids for it later (and be careful until then).
2 topics in this article: carbon fiber, Wills Wing
Cracks on my ATOS
Mon, Aug 6 2001, 6:00:04 pm EDT
carbon fiber|Davis Straub|Rhett Radford|USHGA
carbon fiber|Davis Straub|John "Ole" Olson|Rhett Radford|USHGA
(?-i)John "Ole" Olson|carbon fiber|Davis Straub|Rhett Radford|USHGA
carbon fiber|Davis Straub|John "Ole" Olson|Rhett Radford|USHGA
Upon landing on July 25th, I heard a cracking noise on my right wing. I thought I might have cracked a rib. The right wing touched the ground slightly. Not enough to turn the glider or cause any noticeable problem, other than the cracking sound. I landed into a slight breeze on my feet with a slightly early flare.
I didn't notice any cracks in the ribs and it wasn't until the next day that I noticed that there was a crack in the upper surface of the d-cell. It was a long crack than went all the way back to the d-spar. It wrinkled the sail, or I wouldn't have seen it.
When I took off the sail it was clear that the d-cell had been compressed either from the bottom at the tip by contact with the ground, or from the top pushing down at about 6 feet in from the tip.
The compression break ran to the back of the d-cell and then delaminated the d-spar. When we sanded off the carbon fiber you could see that the spar foam and the foam in the d-cell were also cracked.
It is hard to believe that the slight pressure on the d-cell on landing would have caused such a crack. In fact it is unnerving if this was indeed the case. The forces were so light that it is troubling to think they were enough to cause a major structural failure.
I'm wondering if leaving the glider set up may have caused this problem at an earlier time. Perhaps the glider rocking in the wind got compressed a few too many times. This seems like the most likely cause.
Rhett Radford was able to very quickly repair all the damage. He put four layers of carbon fiber cloth on each side of the d-spar (2", 4", 6", and 8" wide), an addition to replacing the tow material (which we created from the woven cloth). He cut a 3" hole out of the top surface of the d-cell to get into work on the d-spar, then repaired the hole. The leading edge and bottom surface of the d-cell were still intact.
He was able to fashion two layers in the interior, lay up micro balloons to replace the foam, and then put three feathered layers on the outside after we sanded down the micro balloons to create a bit of a cavity. The repair looks great.
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