Witch Hawk 500 Free Flight Story

 In the Fall of 2016 I purchased the Witch Hawk 500 kit from BMJR because I wanted to try a larger glow powered free flight, at that time my only glow powered free flight was Cox PeeWee .020 powered. For 2017 the Witch Hawk was to be the One Design Plane at 2017 Nats. I didn’t get mine built for 2017 Nats and barely finished for 2018 Nats. 

2018 Nats Before Picture

Building a larger kit went easier than a small one in that it is harder to break pieces during construction but I had new things to try with this project. I covered it with Polyspan which I had only done before on parts of models, it went pretty well other than trying to find the shiny side. The fuselage was covered with silkspan. I decided last winter I would like to try an airbrush so I ordered the components for a system; it needed some brass fittings for connections. Local auto supply store helped me with that. I sprayed it with the dye that Larry Davidson sells and that went well.  For this large of model, a larger airbrush might have been better but it worked.

Under Construction

Airbrush Compressor

For a larger glow model running on pressure I needed an electric starter attached to a stand, as I have a small car this had to be compact. I found a plastic stool that folded flat and attached my starter and connections to that. To turn it on and off I ordered a trolling motor foot switch.. This was the first time running pressure and I decided to use a Red Cap bladder for my K&B .19 engine with original needle valve. I ran it on a test stand first and it ran pretty well.

Starter Setup

Before the 2018 Nats I had just enough time for some test glides and to run the motor on the plane. At the Nats I picked the first really calm day to test fly. I was nervous, just sure something would go wrong. First short flight it went straight ahead; stalled and came down breaking the propeller. Added tiny bit of rudder trim, next flight went up and transitioned nice but with no wind it glided back into pit area and hit a golf cart. It broke the wing in half but worse than that broke the scroll off my Texas Timer Max IIIa timer.

First Short Flight

Flew Through Golf  Cart

Broken Timer

Broken Wing

Back closer to home I do not have very large flying fields to use so I made the decision to install RC for motor cutoff and RDT. Later I could install an electronic timer to control the servos. To cut the motor, Greg Stewart gave me the great idea to use a valve made for RC smoke systems, Dubro sold this but I had to order through eBay to find one. Fixing the wing was a fair amount of work but it looked pretty good even after spray paint.

RC Install

Recover After Repair

As the flying season is winding down I wanted to fly it again, Saturday morning was darn near calm but there was frost on the ground. I had a little trouble getting the motor running and when I did it was surging a little. I launched it anyway and it went straight ahead and climbed darn near straight up. If it looked like there was any sign it would crash I would cut the motor. It climbed fine so I cut it when it was getting fairly high, it stalled straight ahead but had plenty of altitude to recover and as it leveled out it went into a nice glide to the right and landed. 

Frost in the Grass

My hands were cold and I needed to be somewhere so I did not fly it again. I was really happy. I know people have told me larger free flights are easier than small ones but I know they can crash harder also.

Bill Kuhl