Oz Report

In a previous Oz Report (https://OzReport.com/3.59), I started a thread about self-towing.  Stewart Midwinter told us about John Theoret, who was self-towing in Canada.  Cas Wolan has written in about seeing John's first self-tow.  Check out what John can do with his tongue.

When we got to the Sunflower aerodome in Yoder, Kansas, we found Jule Lorenzen and his amazing self-towing Honda 350. I've included Jule's story below as well as a couple of pictures.  You'll find more at http://www.1800hangglide.com/selftowing.

Cas Wolan writes:

I and Barney Sullivan («aa797») were witness to John's first successful self-tow on the evening of July 1^st, 1997. John's set-up was as follows: He had 3/16 spectra loaded on a narrow steel reel (4in.) fabricated from an old car rim which included a standoff spacer.  The line then went to a horz./vert.  roller assembly which was mounted off of the front bumper of his late model, full sized car. 

About 1000ft of line was laid across the field to where John launched.  At the car, John had rigged an old radio control receiver and servo to the throttle arm at the carburetor.  At his end, John had mounted a joystick assembly from the RC transmitter to a strap (off his helmet) in front of his mouth, which he could manipulate with his tongue/lips.  The leads from the gimbal went up to the rest of the RC transmitter, which was fastened to the kingpost.

John made several successful flights that evening; all of which he was able to command full throttle for takeoff and then pulse it as needed for climb out (he used a standard Hewett bridle).

I do not believe the (306) number works for John anymore as he moved to Quest Air in Florida to do tug training and has since gone on to Lookout Mountain flight park where he now works

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Jule Lorenzen writes:

I live near the middle of Kansas, where the wind blows most all the time and many spring and summer days feature cloud streets lined up across the sky as far as the eye can see.  I started flying hang gliders in 79, and immediately began dreaming of ways to get into the sky.  By 80 I'd come to the logical conclusion that a remote control static winch might be a pretty cool thing to have, especially since there were very few pilots in my area and my friends and family were not very interested in what they saw as helping me risk life and limb by driving my various tow rigs.  Static line and payout winches were yet to be proven as reasonably safe even to most of the hang gliding world.

Well the dream of self launched flight never died so after having designed and built various trikes and payout reels with good success I decided to tackle making the dream come true.  In 95 I bought a four channel RC radio and started making plans.  I decided to try to use a Honda CB 350 that was sittin' around the place, a clean, nice running bike with a broad power band and plenty of it.

I knew at the time that there were machines easier to build from, Dave Broyles had shown the way with his neat use of variable speed belt drive scooters, but the manual shift 350 was what I had and I knew it'd be an interesting challenge to make it work.  I adjusted the spokes to move the rear wheel far enough over to squeeze a 1" wide spool next to the tire and built a line guide next to the front wheel with a frame tying the wheel to the kick stand so I could stake it down solid. 

Next I mounted a metal toolbox on the handle bars in which to mount the receiver, servos, micro-switches, relays etc.  I decided to use compressed air to do some of the hard work, like clutching and shifting because I could control the action with pressure and volume, so I mounted a used freon tank, a 12V air compressor, a pressure switch and a car battery for extra juice to the rack and sissy bar that were on the 73 vintage bike. 

I mounted a CB radio on the winch to listen to the motor and a noise-maker hooked to the neutral-light circuit so I could "hear" when I was in neutral.  Using solenoid operated air valves and air cylinders to actuate clutch and shifting was fairly straight forward (but by no means easy).

Three servos run two micro-switches each: one for ignition and starter, one for shifting up and down, one to run the clutch and a little device I call the neutral stop, run with an automotive door locking solenoid, which allows me to find neutral whether coming up from 1^st, or down from 2^nd. The throttle is run directly with the fourth servo.  NOT a simple machine but when finished I'd be able to do everything but steer the bike from at least 3000' away (the length of my tow line).

Next I turned my attention to the transmitter, which I dismantled and reorganized in order to have the controls at my fingertips with hands in flying position.  I fly suprone (seated inside the bar) so I mounted the transmitter on my right where I could reach it easily and read the battery power meter at a glance. 

Just for fun I built an ignition switch with key that works just like your car, which is mounted, along with the shifter, on the aft edge of the transmitter facing me. The throttle is mounted at my right index finger and the clutch lever at my left index finger with my hands in flying position.  The biggest difficulties were getting the antennas communicating clearly, ground to ground at distance, and overcoming radio interference from the bike itself. 

This took me quite a bit of time working on and off (mostly off) the next couple of years.  This spring finally saw the success that perseverance often brings, when trying my latest set of antenna brought glitch-free operation and successful test flights of 4-500' in 3/10s of a mile tow distance with light winds. 

It is a very strange feeling to operate a machine that's 1/2 mile away from you but it's beginning to feel routine.  Running the throttle is all I'm doing once the launch run is started, so it's not as complicated as it sounds.  I can quickly and easily adjust tow pressure as wind or thermal conditions change. 

I've yet to break a weak link while testing.  It's really funny to watch video of me launching from my cart, motor noise coming from the glider, but no motor.  Video from the winch end shows the winch starting up, clutching, shifting and towing me up in the background all sans operator!  Definitely fun stuff!

Now the dream is to make the next generation of self-launching winch simple, compact and easy to use.  (Notice I didn't say cheap, that could only come with mass production.) Anyone interested in acquiring a machine of this type or having me modify your current static winch to self-launchability call : 316-654-3148, or e-mail to «self_launch»

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Michelle's dateline story

If you missed her on TV, you can find her story at http://www.msnbc.com/news/277791.asp.

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Gary Osoba writes:

Wouldn't you know it, our weathered-out gathering was followed by fantastic conditions the last 3 days.  The sky has been absolutely full of beautiful cumulus starting early (9-10 am) each morning.  Spacing has been close, at about a 3:1 glide along the wind lines.  Surface winds have been around 15 mph and winds aloft have been strong for long down winders.  The convection has been very large and very, very smooth.  1-3 mile diameter cumulus bases have been present daily.

I didn't fly Monday but sailplane pilots were reporting 600-800 fpm climbs to a cloudbase of 6900' agl.  Tuesday I flew the little Woodstock and found cloudbase at 7500' agl, maximum lift 1100 fpm although most of it was about 700 fpm and incredibly smooth.

Yesterday was the best even though the cloudbase was down to 5500 with pre-frontal instability.  I flew the Gemini to give a local sailplane pilot some XC training.  We selected a turn point upwind to the south-southwest- 53.7 miles.  Running to the turn point into the 25 knot wind, I only stopped to circle once for about 4 minutes.  Coming back, I never circled and used a total of 326 feet to arrive back over Sunflower! 

There was a fabulous buildup of a thunderstorm, which occurred during the flight.  It was situated about 10-15 miles east of our line and started building in an area south of Cheney Lake.  We kept an eye on it as it built rapidly and the area around Cheney became nearly black.  We were in a drier airmass about 2000' above the base shelf of the T-storm and so we had a beautiful view of the buildup above as the shelf continued to expand out toward us.

I figured from the way it was building and its movement to the north that it would eventually impact Sunflower.  With the strong tailwinds and plenty of altitude, my safety margin was embodied in the decision to either fly at 65-75 knots indicated (about 115 mph true groundspeed) and conserve altitude to demonstrate to my fellow pilot how to follow lift lines with minimal altitude loss, or to speed up to 90 or 100 knots and get home quickly (plenty of altitude to spare) if things started to get out of hand. 

For purposes of reference, the strategy in the Carbon Dragon or Rigid Wing would have been to start tracking west and put another 10 miles or so between the buildup and yourself.  This would have been easily accomplished and quite manageable.  Of course, we would not have been that far upwind anyway, probably more like 200 miles downwind by mid-afternoon at this point!

As we returned to the general region of Sunflower, the buildup intensified and lightning activity over in the storm was moving closer, now about 5 miles SE of Sunflower.  The last 25 miles or so I had been calling the ground and asking about wind shifts, velocities and any signs of a gust front at the surface.  Nothing notable, but I knew it would come.  The final few miles, we started to encounter the wall of vertical air feeding the west side of this thing. 

We pulled up over the finish, and then I ran back upwind to check out the lift briefly.  On returning, we flew a 5 mile stretch at an average true groundspeed of 170 mph, going up the entire time 400-800 fpm.  We ran about 2 miles west to get out of the bigger lift and had to find some sink to core to get down because with my landing flap deployed and nose pointed strongly down we were still going up.

We returned to the Aerodrome with landing altitude and the surface gust front was underway.  On approach at 60-70 knots we were standing still.  I pulled in the flaps and flew a very slow approach at 80-90 knots indicated.  After we landed and had stopped we stayed in the glider until the gust front passed because we had been gently lifted up twice *after* landing from gusts.  It these situations, you stay with the glider and fly it to manage the ground winds.  When it calmed down (30-40 knots), we had the glider hangared within about 5 minutes.  The storm proper passed to the east on its northerly trek and we never got rain at the glider port.

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