Glider Tug Advice Needed.

[David Davis]

1. There is a lot of interest in gliders at my club. We have a tug, some sort of French design, a low-wing model with twin fins, a tricycle undercarriage and a 25cc Super Tigre glow for power. It seems a bit fast and heavy. I have a WOT 4 XL fitted with an Enya 120 fourstroke and would like to fit a glider tow release to it to give the club an alternative. Are there any commercially available?
2. If the engine isn't powerful enough I have the same Super Tigre engine or a Laser 150. Would either of these be better as an engine for a tug?
3. Finally, if I were ever to build a glider, I am tempted by a large slow-flying vintage design like a Sunspot or Thermalist but I've been told that gliders without ailerons are difficult to tow. Is this true?
4. Finally, are modern tugs too fast for vintage gliders?

All advice from experienced glider guiders gratefully received. .

[Andy Meade]

1) You can use the same glider release mechanisms that are available from model shops, with the correct reinforcement. If not, they are fairly easy to manufacture on the tug end.

2) I can't really answer that, as it depends on the size of the gliders you are tugging up.

3) Yes that's true - you need to be very positive in roll control on the tug line - i.e. keep wings as level as possible.

4) Not at all - one can either use flaps and/or the throttle to slow the ascent up.

Here are some nice diagrams for you

 

Edited By Andy Meade on 14/11/2016 16:37:28

[Anthony Scott 2]

There is a tow attachment./release specifically for the WOT 4 XL available .

[Barry W]

The French tow plane you mention is called a Bison and is one of the most popular tugs used in France.

When I lived in France I had a 2 channel glider similar to a Gentle Lady by Carl Goldberg. We used to tow it up with a Bison.

The thing to do is get the tug pilot to climb vertical or as vertical as possible and the glider will follow.

It is perhaps net very elegant but is cuts the speed down and the poor glider has to follow.

If things did get out of control just unhook.

Hope this helps

Barry

[David Davis]

No apologies for reviving my old thread. I've fitted a glider tow release and a Laser 150 V Twin to my WOT 4 XL and I'm due to use it as a glider tug for the first time on Wednesday. The glider is a 3 metre ASW ARTF.

I have never flown as a tug pilot before.

Any advice?

[Andy Meade]

Don't bother with circuits. Flat out and straight up is best. Finger on both releases.Ensure the glider has released properly ( a flag on the line near the towing eye will help this) before you shut the throttle and dive away. Throttle back a bit at release to take the tension off the system. Be careful on your landing run as the line will be considerably lower than your tug - don't snag a fence!

[Frank Skilbeck]

David, for the tug pilot keep the turns steady and talk to the glider pilot. Make sure the tow release works reliably and if anything looks like it is going wrong the drop the tow line. If the glider pilot got experience behind a tug, then good, if not tell them not to try and turn with the tug but just keep the wings level and let the tug pull the glider round.

The only other advise is that keep the tow line as long as possible, this reduces the impact the glider can have on the tug.

But generally towing is a bit of a non event, we actually prefer to test fly scale gliders behind a tug rather than chuck them off a hill.

[Trevor]

I agree with all the above. The tug pilot’s main job is to maintain a steady climb rate in order to keep the line taut. The glider pilot must keep the wings level at all times, especially during turns. If he feels the line is tending to slacken, it’s better to deploy a bit of airbrake rather than wrestle with the elevator.

[David Davis]

I'm afraid that my first experience of flying the tug was anything but a non event!

I had fitted the towing point in the wing about the position of the cg, as recommended in the WOT 4 XL kit. Once off the ground the glider pulled the tug upwards all the time. We spent a minute or two trying to correct matters but the attitude of the tug was all but uncontollable. Wisely, the glider pilot, who had once competed in the French National Championships, unhooked and landed but my troubles were not over yet!

I found that I had no control over the engine speed. The engine coninued to run at moderately low revs and it was all I could do keep the model in the air. Advancing and reducing the throttle had no effect, even the kill switch didn't work. In the end I dumped the towline and landed hot. The model flipped over but no harm was done. A small nut, part of the throttle pushrod had unscrewed itself, disconnecting the carburetters from the throttle servo, consequently, though the servo was working and moving the pushrod, this had no effect on the engine speed because it wasn't connected! I have since fitted a locknut and coated the threads with Loctite.

I am going to fit another glider tow relaease behind the trailing edge of the wing as others have recommended.