Getting the flight performance data
Good flying conditions allowed us to do several test flights last week. Sören flew in quiet conditions at 8am in the morning as well as in the afternoon with thermals and ridge lift.
Tested speed range: TAS 40-160 km/h
When flying straight in quiet air the vario and GPS recording show sink rates below 0.5 m/s at slow speeds of 45-55 km/h.
Naviters “See You” statistics indicate an average sink rate of 0.7 m/s when circling for 8 minutes at 30-50 degree bank. That's what we expected. A good speed for thermaling is 55 km/h at a radius of about 20-25 meters. So climbing in ridge lifts and thermals is easy, even in marginal conditions.
At higher speeds the measured performance is better than calculated: around 1.2 m/s at 120 km/h TAS. Note: the current cabin does not yet have a retractable landing gear, which is planned for prototype no 2.
When comparing the polar of the 1comet foot launch glider to the polar of the well-known K6, the 1comet seems to clearly fly better below 100 km/h and equals performance above 100 km/h. This shows that the 13% laminar airfoil with flaperons works really well.
Stall: docile stall with light buffeting; the nose goes down about 20 degrees below level flight.
Stall speed: at about 38 km/h IAS for 16.5 kg/m2 wing loading and “normal” CG position; stall speed increases when CG moves forward. Note: The current flap system does not allow to set the flaperons to the optimal position for landing.
The drag chute is reasonably efficient, but deployment is not yet sufficiently reliable with the current system. When it’s not opening completely you end up 600m further down the runway. The drag chute system of prototype no 1 will be improved; protype no 2 will get conventional speed brakes. And: we´ll change the hanging stick to a conventional side stick.
Performance: incredible, considering that the 1comet is a foot launch glider.
Link to this article: https://OzReport.com/1593447405