I learnt to fly models about five years ago on a three channel Super sixty powered by an OS 40 FP. Unfortunately this model is now no more due to a mid-air with a Uno Wot that was almost unscathed in the event. This, ironically, came about in an attempt to keep clear of two gliders coming in on finals.

About three years ago I was trying to think of something to spice up my interest in flying models. Not exactly bored with flying, but I was beginning to loose stimulation from what I was doing. I cannot remember now what it was that started my interest in aerotowing, whether someone suggested it or whether I had read about it, probably both, but the outcome today is that I am hooked.

I have teamed up with Chris Podbury, whose interest is mainly gliding and Chris and I regularly aerotow at the club site on Woodbury Common. We also go to other venues to perform this particular form of our hobby. During 1998 we aerotowed at the White Sheet Aerotow meeting near Mere and rubbed shoulders with Steve Vine and Steve Holland, two excellent tug pilots, greatly in demand at these events. We were also privileged, to share a slot at the Woodspring wings 98 model and full size display at Yatton near Bristol, again with Messers Vine and H. We met up with Steve Vine yet again at two other meetings, a BMFA Fun Fly at the Tavistock club site at Brentor and at the Redruth and District club public display at their site in Cornwall.

The tug that I have been using to date, (May 1999), is a fifth scale Carl Goldburg Piper Cub, Anniversary edition and the Laser 80 four stroke engine driving a 13" x 6" Master Airscrew propeller has been a faultless 'workhorse' powerplant for the Cub. For general flying the engine size is far bigger than necessary for the Cub and at quarter throttle is very scale like. And when the Laser 80 is at full chat, it's nicely matched for fifth scale gliders on the tow.

Chris has three gliders that he uses for towing. The one that he used as a guinea pig at the start of our exploits is a Gryphon (1). This model is very steady on the tow and has fortunately proved to be an ideal choice for cutting our teeth on. So steady is it, that it has been towed from the ground to the point of release without any input to the controls from Chris, even gentle turns made by the tug were slowly mirrored by the graceful flying wing. The Slingsby Dart a Pat Teakel kit built (2) This model has made it possible for us to perform a scale display bringing a realistic look to the hobby. It has also brought with it a lot of realistic problems, correction, challenges, mostly overcome now with minor modifications and practice. Chris's latest model is dual purpose, as are the other two, a slope soarer that can be towed. (3) Like the Dart, providing the speed does not drop too low, this also performs well on the tow.

We have used two styles of cable release:-

• A manufactured variety with a short piece of metal cable (probably Stainless Steel) with a small Brass ball fixed at one end and a loop at the other end to attach to the towline. Inside the nose of the glider is a very cleverly designed release mechanism. I'll not go into the nitty gritty of the design except to say that it comprises of only two pieces and like all cleaver designs it is very simple and smooth in operation. The Brass ball enters a hole in the nose of the model and is trapped inside when the mechanism is closed. When opened again the ball is released. Even when the towline is under a lot of tension, the mechanism works with the greatest of ease and very little effort. However this is now not our preferred design as we have found that if the glider over shoots the tug in the air, the wire bends and prevents the ball from being released until the glider then falls behind the tug again.
• Again a simple design. A hole on the underside of the nose allows access for a loop at the end of the towline to enter and be held by a pin that is slid forwards from a tube across the hole into another tube. The towline is simply released when the pin is drawn back across the hole. This is very effective but when the towline is under tension there is some increased friction between the pin and the tube. This under one extreme test condition on the ground has caused the release to fail, but as yet this design has never failed in service, and is now the favourite.
• There are other designs, variations based on the previous design that can be used for either tug or glider

My current aim is to own a quarter scale J 3 Piper Cub, powered by a G 62 Zenoah petrol engine, driving a 24 x 8 propeller. This tug would be capable of towing up third scale gliders.

©EDRCC July 1999