AeroTowing a quick introduction .
Model glider aerotowing in years past had a reputation as a bit of a black art, something not to be attempted by mere mortals. But not any more. Aerotowing is becoming more popular mainly due to the increase in available tug pilots. As you might expect it is not advisable to attempt aerotowing with just any old powered model, and in fact thanks to the early pioneers a definite package in terms of airframe and engine has emerged. (photo right shows a good starter package of 1/4 scale Piper Cub and 38 or 62c.c. petrol engines. Beer bellies are not compulsory).
What do you need to get started:
Well if you are a glider pilot very little. Just a model glider, preferably
1/5-1/3 scale, slightly dependent on tug size and power, fitted with a suitable
tow-release. You can use either a commercially available release of which
there are several, Flair products being one of the more popular ones, or you
can make your own by simply fitting a tube to the inside of the glider nose
(position is not critical to the centre or either side, but not recommended
on the underside) which has a pushrod connected to a servo on switched channel.
The tube has a slot in it which corresponds to a slot in the fuselage side,
then all you need is a loop of suitable line to connect to the tug line. Do
not assume the tug pilot will have a release to match your setup. Supply your
own which will connect to the loop on the end of the tugs line.
If you want to be a tug pilot, it is a much bigger deal. To be able to tow decent size scale gliders (which is what it is all about) you will need a suitable model. Spacewalkers, Turbulents, Pawnees, Wilgas all make excellent tugs, but I think to begin with you can not go wrong with a 1/4 scale Piper Cub. Power plants ideally should be petrol minimum of 38cc (Zenoah being very popular) and 62cc is ideal. Petrol is chosen for many reasons, it will work out more economical than glow, the tickover reliability is far superior (very important) they are much cleaner to operate etc. etc.
There should be a tow release on the tug itself, on the Cub it is situated on top of the fuselage, and always just behind the centre of gravity. And of course you need a suitable line. We tend to operate with lines 20m in length, longer would possibly be more suitable (particularly when circle towing) but the size of our grass patch precludes this.Ideally pilots should be B.M.F.A. 'B' test holders especially if you intend to fly at one of the many fly-ins organized especially for aerotowing.
Launching is just a matter of connecting both models to the line, and checking the operation of the release. Lining up into wind the tug will take up the slack, a helper supports the glider wing until sufficient airspeed is achieved, and with both pilots standing together behind the models, the tug pilot will announce 'full out' which means there is no going back. Your pride and joy will be towed aloft, with you the glider pilot doing very little apart from keeping the wings level, until you 'speck out', hit the release switch and sniff out that superb lift.
So there you have it. All of you with a scale glider and no tow release shame on you! Get one fitted and come to one of the many events that are held each year. Check the modelling press. You will be sure of a warm welcome. Make yourselves known to the organizers of the event that you are are new to aerotowing for that extra special treatment and an introduction to the tug pilots. See you at the next event.