Aerotowing

[paul needham]

Hi everybody, have been trying aerotowing latley but with mixed success, tug plane is a T-240 with 45cc petrol engine, tow release on the trailing edge of the wing centre. The glider is a Flair 25% ASK8, tow release in the nose. The tow line is 50m, think this is too long, can anyone recomend a length that makes things easier ? Thanks, Paul.

[stuart cotgrove]

Having only just stared towing I am not the best person to advise. The lines we use from a 62cc Greenley are builders line and can't be more than 100'

What problems are you having?

And how does the T240 go with the 45cc, would it take a 62cc would you think?

[Pat Marsden]

Paul

The longest towline we use is 40 metres long and this is on gliders around 7mtr span, more usual is around 30 to 35 mtr for models around the size you are towing. I normally use the orange builders line from B & Q but for I also use the builders line from Jewsons as its a bit lighter.

Hope this helps

Pat

[stuart cotgrove]

don't forget a swivel too, without one all that stretching will wreck the twists in the strands.

[barrie burton]

We have 2 tugs in the club and have been towing for many years.My own tug has a 42cc up front,the other has a 80cc providing the power,but both have one think in common,the line attachment on the tug is at about 60% cord,ie not too far behind the Cof G

[paul needham]

Thanks for your comments everybody, will try with a shorter line, the main problem is that we get some slack in the line then things go wrong. The 45cc in the T240 seems to pull the glider up reasnably well, think a 61 might be a bit over the top in it. Thanks again, Paul.

[stuart cotgrove]

It's the slack that gets us too. We appear to reduce problem that by climbing faster with the tug.

Is the slack when running straight, or on the turn?

[paul needham]

usually on the corners when we loose it.

[Dave Hoare]

Hi Paul,
Provided the tug does shallow turns and the glider stays wings level(not trying to follow the tug) you should be OK. We use a towline about 30 to 35 m long with a sock/rag at the glider end of the line to enable visual seperation at the release point.
We(TVSA) are running an aerotow at Siege Cross this Sunday if anyone is interested.
SiegeX is near Thatcham(east of Newbury) in Berkshire.

[stuart cotgrove]

Hi Paul, as you know we are learning too, had some great success today following advice from fellow LMA members.

Using a 62cc Super Duper Greenly and a Multiplex Alpina (around 4,) we found the following but would be keen to get some comments..

Too much elevator on the glider promotes difficulties, use just enough to keep the glider above the tug.

Keep the tug climbing aggressively

All turns to be done shallow by the tug, the glider doesn't need to turn, just keep the wings level and it will follow the tug.

Set the tug up to climb on the trim, or use low rates to help with smoothness...

Ensure that during turn that the climb is maintained

Difficulties arise from not seeing the tug clearly, the glider disappears in front of some clouds and need to be kept in profile rather than seen from behind.

Oh, and ENJOY...

[Barrie King]

Hi All,
What type of release are you all using, bought ones or home made, just picked up a bargain glider from Wings and Wheels and hope to try towing this week.

Barrie

[stuart cotgrove]

on my minimoa I glassed a brass tube into the bottom of the fus about four inches back from the nose, then dremelled a slot in the bottom through the tube wide enough to slip the towline wire tether. Then a piece of piano wire attached to a servo allows the wire to pass through the brass tube and pick up the towline looped through the slot.

[Barrie King]

Hi Stu,
Thanks for quick reply, will make a similar one for mine, do you use a release at the tug end in case things go pear shaped?

Barrie

[stuart cotgrove]

Hi Stu,
Thanks for quick reply, will make a similar one for mine, do you use a release at the tug end in case things go pear shaped?

Barrie

Yes, absolutely. I made up one based on John Greenfield's design, happy to forward pictures or a link if you need be. Basically a hoop let into the top of the wing at 75% back from the leading edge, or on the fuselage top immediatly behind the wing. Then a wire that traps the loop that is inserted through the hoop... How do you post pictures on here?

We have had a glider that got out of shape and rolled on the towline, and wrapped the line around the glider fuselage preventing it from releasing. Simple switch flick on the tug and it released and both planes were saved....

Would not fly without releases on the Tug and the Glider.

[John Greenfield]

Stuart

It's all good advice that you have given (wonder where you got it from !?) but I would suggest that the glider pilot stay off the elevator and rudder during the tow. If coupling is used between aileron and rudder, switch it out during the tow (why not use the release switch to also control the coupling). All the glider pilot has to do is keep the wings level, even during turns. The tug will pull the nose of the glider round if the tug makes a smooth low rate turn. You are also correct that the tug should maintain the same rate of clime in the turn to keep line tension constant. Using the elevator to control the position of the glider especially at height can lead to oscillations in pitch which can then cause snatching of the towline.

Lots can be written and said about the art ? of aerotowing but there is nothing like going out with people practiced in the art of towing to see what they do and talk to them. You will find exponents of the art more than happy to assist and you will find there are aerotow events around the country regularly during the summer. Look at the calendar on www.scalesoaring.co.uk for details.

Happy flying

John Greenfield

[stuart cotgrove]

Stuart

It's all good advice that you have given (wonder where you got it from !?) but I would suggest that the glider pilot stay off the elevator and rudder during the tow.

Happy flying

John Greenfield

I wonder John.

Yes, all advice and help has come from John Greenfield, Steve Mitchell, Pat Marsden (yes I still owe you a tea Pat... and Stuart Mackay.

It's amazingly striaghtforward once you get good advice....

It does appear any difficulties the glider get's into is as a result of misuse of elevator/rudder so that's my next skill to "crack"