Friday, September 7, 2018

Witch Hawk Repair & RDT

I was reading an exchange on Facebook recently that started out with someone giving a negative opinion of the use of Remote DT in free flight competition. This is not the first time I have heard comments like this and I can understand why people feel that way. Some people didn’t even like the idea of trackers but I think for the majority of the free flight population trackers are essential equipment. 

Witch Hawk 500 Repaired

The longer I fly free flight airplanes the more I appreciate the challenge of making a model airplane fly with no control from the ground. It can be a lot harder than it looks to get a model adjusted to fly consistently without control. At times it is frustrating not to be able to save the model from a spiral into the ground that results in more repairs. The rational for not liking RDT was the model was not truly flying free if you could bring it down at will; they also liked the thrill of the complete chase of the model. Another comment that came up was a dislike for auto surfaces, something I doubt I will get to that level in model complexity to use.

RC Install Underway

In my Witch Hawk 500 that broke the wing in half at 2018 Nats I am installing RC for DT and to cut the engine. When I feel the plane is trimmed I will attach an electronic timer to the engine cut off servo. The largest field I fly from in local area is 44 acres and the field has trees and powerline around the edges. Flying at the Minnesota contest field there are trees on one side that I really want to stay out of.

I was checking on eBay for mechanical timers and did not see a single Texas Timers timer, really not much of anything. Also looking for a Cox TeeDee .020 and have gotten my bid up way higher than I wanted too.

Dewey Bird and Stooge

Last evening I did fly the Dewey Bird ½ A control line model. I made a really crude stooge to release it with but it worked okay. The lines I had .012 were too heavy and maybe too long at 35’, tension was not great but then it is a small model. With my free flight experience I am getting more concerned with details, finding out the hard way details matter.

Bill Kuhl


  1. Bill, re the Dewey Bird setup: Yes, .012 lines are FAR too heavy for a small plane like that. If you don't have .008 lines available, just use .010 kevlar thread or the old standby, Cox Dacron lines. They're a bit draggy and stretchy, but much lighter than steel lines, so 1/2 oz tip weight is very effective.

    ...and, no, 35 ft lines are not too lap times in the 4.5 second range, manageable for old crocks like us. It appears that you're using a Baby Bee engine, best run with a 5-3 Cox black (or equivalent APC) and 20-25% nitro 1/2A fuel. That setup WILL fly and stay out on the end of the lines!

    Dave G.

  2. Dave Thank you for you comments, I am going to trying shorter lines but prefer to turn slower. I will also try lighter lines that are longer.