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Tuesday, December 13, 2011

Powered Paraglider Trike, Snow Launch ... No Fly Day

There was 4 inches of 3 day old snow on the field at Vance Brand.  We were planning on a mid day flight despite the clear blue skies.  Robert assured me that the thermals would be minor due to the cool air.  I had never flown inland mid day and was a bit apprehensive but it had been awhile and I was game to fly.  So after a short delay getting gas I arrived at the field where Eric ( new pilot ... student of Robert's) was waiting to launch.  He had brought his mother to see the amazing flying machine.  We chatted until Robert showed up and watched a stick of sky divers.  They were having a great time sliding in fast and skimming along the skin of snow.
My first attempt was from the pond toward the hangers.   I motored up and down the course a few times to test the surface and see how the Falcon handled on the snow.  The front wheel was tracking fairly well but as soon as I started a mildly hard turn the buggy would go into a slide.  It was slippery and kinda fun.  The CG is way behind the front wheel so when it broke loose it didn't take much if any thrust to continue the spin.


Eric's 5th flight

The launch was a bust.  When I got close to lift off the buggy started to slide to the left.  I was using minimal brake and max power.  When I aborted the wing came down clean with no damage.  Since there was no real breeze I layed out to try the other direction, moving 50 feet to the north to give me room to clear the swoop pond.  Second attempt was the same thing.  Looking at my tracks in the snow it was clear that as soon as the front wheel left the ground the trike would start torquing into a left hand turn.  I set down twice to get back on track and finally aborted.  The third attempt was the most dramatic.  I allowed the rig to lift off and when it drifted back down I was at a dramatic heading not the same as the wing.  When I touched earth the unit spun out and I was done.  If it had been on anything other than a skin of slippery snow I would have rolled for sure.  Remember Bubba's? 
Robert said the wing was surging and falling back due to the drag of the trike as it passed through different thicknesses of snow and perhaps I would have been better off using more brakes.  It might have worked but launching with brakes leads to a slow takeoff and possibly coming back down, maybe at the wrong heading for the wing.

Robert setting up for launch
I think the "P" factor is at 2 o'clock .... pushing the trike into a left hand posture.  No problem on hard surface but a bear on a slippery surface.  Knobby tires on the back might have helped but I don't think it would have stopped the left hand turn since the wheels turn independently.  If I wanted to go balls to the wall I would have gone no brakes till the wheel lifted then popped up and prayed that I had enough lift to keep from touching.  Risky business.