Platform Launch

Every now and then my knees start giving me a problem, and I wonder if I will be able to continue foot launching.  When that has happened I have thought about using a platform launch method for the Mosquito.  But I never went past thinking about it.  B Asher did more than think about it, he developed the method and uses it regularly.  His motivation was not having a smooth enough field for launching the normal way.  What follows are photos and text from two posts made by B Asher to the FLPHG List:
http://groups.yahoo.com/group/flphg/message/9841
http://groups.yahoo.com/group/flphg/message/15897

"I started flying my Mosquito about 5 years ago, and in the first 3 years, I broke 3 props, or approximately a failure rate of one in 12... As long as I have the correct wind, about 5 to 10 MPH and it's straight in, no problem.

This procedure grew out of necessity. My dad's farm is completely over grown with 20 ft trees , I cleared a path 25 steps wide, and 400 steps long, and then mowed a road 5 ft wide down the middle. No where near big enough to launch from, if foot launching, but no problem from the back of the truck.

"2 years ago I started experimenting with Platform Launching. I believe I have the procedures fairly worked out now. The main problem was finding a weak link strong enough to hold me and the glider, and wind pressure up to 35 MPH.  I have settled on the 3-ring rope release, developed By ATOL several years ago. The more common Air-to-Air cable release was not strong enough."

Tow Release Detail

(I started out by) "simply mounting a 2x8 x about 7 ft long board to the back of my old Ford Pick-up. Do not mount on the tail gate, that's not high enough to keep the legs off the ground.   My old truck became fairly hard to start, so I switched to a more reliable system.

"I am currently using a small, 4 ft x 8 ft, utility trailer, with special 3 ft tall bar stand mounted on the last quarter of the trailer. The open bed pick up truck worked well, and gave a much smother ride. Turbulence from the pick up or car has never been much of a factor.

"Note: the release line is shielded by an old baton tube, This is critical as you must limit wind pressure and bouncing of the line.

"Another advantage is priming the pump. At rest, the harness and engine are hanging almost completely vertical. So it much simpler to eliminate all the air bubbles from the gas filter and line.

Rigged in on trailer

"I am launching 'Pronged out' out of an un-mowed, open pasture, As the Mosquito legs never touch the ground, and the tip of the prop is at least 3 feet off the ground, so tall weeds are no longer a problem.

"One problem is, you need some one to drive the car. and you may be training a different crew each time. As long as I am with Hangglidding people, no problem, they get it. The Laymen have more trouble grasping the concept. The instructions are, Drive, "accelerate" as fast as you can, and watch the air speed indicator on the front rack. When that hits 35 MPH, Level out at 35 and keep driving to the end of the clearing. Sounds simple enough, but the basic WOFO has trouble driving fast enough !!!

Ready for launch

"Launching or 'pin out' speed varies, depending on the Glider. This one, an HP-II-170 has a stall speed of 25 MPH, It's very heavy and fast and was originally built to do aerobatics... so I launch it at stall + 10 MPH. If I pin out at 25 it simply floats off the bar stand, at 35 MPH it pops up, and I immediately have about 20 ft of altitude. Which is very important if surrounded by 10 to 15 ft trees.

"It is so smooth, and so EZ. I now wont launch any other way. I can launch in a direct cross wind, as long as it's fairly light.... Just like platform towing.

"Stalling or popping up has not been the problem I thought it would be because when you go from 1/3 ~~ to full power the extra thrust naturally pushes you forward in the control frame.

"I am off the platform in approximately 50 yards. and immediately have 25 feet of altitude. Then weather vane into the wind and climb out...

"I have not broken a prop in over 2 years. 

B. Asher

Back to Technical

Wind Drifter Home