rclinks2002

My Feedback: (2)

Hello, I was wondering what everybody thinks about this setup for aerotowing a glider.

Carl Goldberg anniversary cub with .61 OS FS 4-stroke It has flaperons which add a significant amount of lift and steepens the climb angle.

The glider is a gentle lady 2 meter 2 channel, or a converted powered 2 meter glider with ailerons added.

Does anybody have any experience with a towing a 2 channel glider? Is it smart? or should I just use the one with ailerons. Also the the Cub overpowered/underpowered or just right; too fast? too slow? Will it tear the wings off the glider??

any thoughts???

TheParrot

I currently tow gliders using a Great Planes 40 size cub with a 91 four stroke. I've towed 2 meters and my dads 13 foot glider. The 2 meters are no problem at all. Keep at a high climb angle and you can pull em up at about 3/4 throttle. The 13 footer takes full power, and is a lot tougher. That being said, I wouldnt go with anything less than a 70 Four stroke for towing 2 meters. We have a .61 in a citabria, and switched it to a 70 for a while. The mounting is the same but you get a ton more power. The 70 would make it much easier, and in this case, its better to have too much power, than not enough.

As for the glider, I've towed a Pierce Arrow (very similar to the gentle lady). We almost wrecked it twice trying to do an "off the ground" tow. What we found works best is if the glider pilot holds the plane in the air and as the tow plane starts to go, give it a gentle toss. This gets the glider flying right away and if the tow plane has enough power you'll be climbing in no time. Good luck!

BMatthews

There's some background available in some older threads I saw about polyhedral and aerotowing. Try the Search.

The Cub sounds good but beware. A buddy with a low powered four stroke Kadet and me with my 2 meter aileron model tried this some years back. My aileron bird was able to glide faster than the Kadet could fly while climbing (or attempting to climb). I had to hold some back pressure to avoid gaining on his Kadet and my glider ended up way higher and behind looking like it was winch launching off the back of his Kadet. It was NOT pretty.

We got one decent launch this way and a near disastrous second attempt before I cut loose and that was it for our little experiment.

Speed, within reason, in the tug is thus a good thing. Perhaps go for a one inch higher pitch and reduced diameter on the prop from what you are running now to help out. Try it if needed.

When it works out it's magical. So try it and see.

Hint---- be sure you and the glider pilot know what you're going to do. A very large and smooth circle in the climb will let the glider pilot follow with less stress. My buddy goofed a bit on the bad second flight by tending to segment his turns into short straight followed by sharp angle turns. Just take off and use the rudder and elevator trims to set up a nice big circle. Then be patient while the glider matches you.

For takeoff we could not tow my glider off the grass so I ran and released the glider when it was light in my hand and we were off from there. I suspect this would work for the Gentle Lady as well. Be sure the glider holder ONLY releases. If he throws forward then the line will go slack and then the whipping about starts... and that ain't purtty either.....

Wayne22

My Feedback: (2)

It might be fun to try, but don't hold your expectations too high. The cub is very draggy - especially the small ones - and a lot of gliders will easily pass them under tow. Also the relative light weight of the tow plane allows the glider to yank it around (as Bruce mentioned above) making it very difficult to fly. You might get lucky, but if not, don't be afraid to cut him loose...

rclinks2002

My Feedback: (2)

Ok so I have decided to get a magnum 91 on the same cub to tow the glider, I fabricated a tow release on the wing of the cub at the spar. It should be interesting. I also plan on using about 100 feet of tow rope and plan to use a flying area that is large enough so I dont have to execute any turns. I will keep you guys informed....

Ben

0gravity

My buddy tows my Oly II, which has approx 110" span, has only rudder and elevator, and has a polyhedral wing. The tug is a Magic with a OS52 4 stroke. It looks hilarious, but it tows fine and is a blast. No problem getting the glider off the ground. The only issue we've had is towing too fast and snapping a glider wing (this has happened twice). The Oly II, like the Gentle Lady, is a thermal glider and likes to go slow.

TheParrot

Ben I'm not sure if the spar is the best place, but it might work. Most that I have seen (and mine) have the release at the trailing edge of the wing.

rclinks2002

My Feedback: (2)

Yay it worked. I put a Magnum .91 four stroke and it worked pretty well, and after a few experiments with different tow ropes we have finally perfected towing.

TheParrot

Good to hear! What did you use for tow ropes? We've always used heavy duty kite string.

owntor

There was an article in AMA magazine about 12 years ago about aero-towing. Discussed mostly large gliders and having a rolling cradle for off the ground takeoffs. Bungee and heavy test nylon line used for tow line. Tow hook release in nose of glider and tow line attaches to back pegs/screws of tow wing. I rigged my planes for this setup. (I linked the hook release to the elevator servo. So a large input up would release the line.) Alas, I never had a willing partner to try the towing. Maybe someday.

Since then I have been towed/launched off a saddle/cradle mounted on top of the tow plane. This works relatively well, but beware when you release from this system it helps if the powered model dives slightly to generate more lift for the glider to release and fly away. There is potential for gliders which require more airspeed to sit on the cradle when released and (without enough airspeed) fall off the saddle. Imagine what can happen in that case. This never happened to me, but we had a close call.

Best of luck!

CHassan

My Feedback: (13)

I fixed up a very tired and well used gentle lady with a nose release and towed it up behind a Tiger 60. It was a little fast and got real squirrley on the controls. We switched to a Sky Tiger with a 40 in it and had no problems. Never had much altitude because the older tow pilot could not see his plane when it got very high. Managed a dozen or so tows. Had problems starting as we just set the glider on the ground and let it drag across the ground. More than once it would ground loop.
Great times and I learned alot, just gave up on it.