Techniques for maintaining vertical positioning on aerotow

[gondukin]

My usual "technique" for maintaining position on aerotow easing the stick forward or back to maintain vertical position as best as possible. In the case when the tug is descending relative to me, this can result in a slight bow in the rope as I ease forward which, once stabilised, I'll try and ease out without it snatching too much.

On a recent foray, I was in position when the tug started descending. Despite easing the stick forward, the tug continued to descend more than I was comfortable with. I therefore eased the stick forward some more, gaining airspeed and resulting in a significant bow. Deciding this was beyond my ability to deal with, I ditched the launch at 750ft and returned to the airfield.

In post-flight debrief with the DI, it was suggested that one possibility is to briefly crack the airbrakes. However, I also spoke to the tuggie and he had nothing to report other than I just disappeared, so I suspect the sink wasn't so severe to warrant that, although it's useful to know. My suspicion is that actually I need to improve my aerotow technique, or possibly I just over-reacted to the position (or a bit of both).

I intend to have a chat with an instructor and take a check aerotow next time I'm at the club, but in the mean time, do any of you fine ladies and gentlemen have any suggestions? I tried the BGA safe aerotowing guide, but it doesn't seem to cover general technique.

[460]

Good question godunkin.
A gliding forum might be the best place for aerotowing advice: gliderpilot.net as you are in the UK.

[OpenCirrus619]

Last year I did an Aerotow check ride and the instructor decided (since he knew the check was, largely, a formality) to throw a new twist into the mix - descending on aerotow.

Not something that you'd do on a "normal" aerotow launch - but a necessary skill if you're doing a long cross-country retrieve and aren't happy "pulling off" at the start of the descent.

It also added to my experience - I now know what will happen if I crack, or even fully deploy, the airbrakes on tow. As a result a bow developing (in particular because I've swung wide and am now overtaking the tug) is no longer an issue for me.

Ask your instructor to give you a lesson on "descending whilst on tow" - great fun it nothing else.

OC619

[RatherBeFlying]

Aerotow becomes a different beast when the tug is not climbing. I landed at another airport and had the tug come for a retrieve. Once it levelled out, serious bows developed and, not thinking of the air brakes, released shortly before the tug pilot was about to do the same.

A sideslip can also help.

After a few hundred tows you will wonder why you had so much trouble ;)

Hint: Just sit there and do as little as possible.

The Condor simulator is much harder to fly on tow than a glider. It can sharpen up your perceptions and reflexes.

[sablatnic]

Just to show what we are taught in Denmark.
https://www.youtube.com/watch?v=2RTGEKkO_fc

And it is absolutely correct to crack open the brakes when descending, to keep from overtaking the tug.

[x933]

Cracking the brakes works a charm. Also works when you are in straight and level - ie aerotow retrieve - and stop paying attention.

Going into low tow can also help for long periods of straight and level, and keeping a bit of forward trim.

Be very careful when you do crack the brakes though - especially if your gliders brakes have a tendency to suck out. Also worth mentioning that in the descent you may need to remind the tug pilot of your maximum aerotow speed.

I'd be interested to know why you were descending at 750ft on tow though? The only time I've had to descend on tow was because we were at cloud base and the guy on the back chose to hang on...no, I don't know either.

[India Four Two]

All good advice above.

A bit of yaw for a slack rope and then airbrakes if required. We teach descending-on-tow as part of the Spring Checkout at my club in Alberta.

[eagleflyer]

We did touch-and-go´s while on tow occasionally to get current again and to practise a malfunctioning hook. Using the airbrakes is perfectly fine as long as you don´t slam them out.
When on vacation in Hungary we would always do low tows behind the Wilga. That was the way they did it there. On cross country flights it´s so much less exhausting, you can hardly loose sight of the towplane, especially as the instructor.

[mary meagher]

Ah yes. I've considerable experience on both ends of the towrope.

In my early days I had trouble following the tug, Dudley Steynor, a very very senior pilot who instructed at Wycombe during the 1940's! suggested that my left hand hold the right wrist, and this cuts down overcontrolling. That worked well for me.

As for following the tug on a descent, or if you develop a bow in the rope, yes, a cautious use of the airbrake will work to straighten things out.

Tug pilots don't always realise you have departed, seeing the glider out back with a wobbly wing mirror is not definitive! Whenever the tug waves you off, it may have engine trouble and if you don't obey you will find the glider is required to bring the rope home again! Don't worry about that, it trails nicely under the glider without hampering the controls! and it doesn't drag on the ground, but you may want to land long in case it catches the hedge....or simply dump it over the airfield when at a sensible height.

I was towing back a K13 from Wycombe with a PA150, and talking to Upper Heyford ... our progress into wind was so slow we didn't show up very well on their radar! (remember Mathias Rust and the Cessna in Red Square?)

At any rate, Heyford warned me that there would be a couple of fighter aircraft passing near our combination - no radio in the glider, so they were quite surprised, and got well out of position...not behind the tug, but beside me! with a tremendous bow in the rope. I was wondering what to do, but as so often, the answer was do nothing, carefully. And the glider sorted things out by gentle use of airbrake, back in correct tow position.

Correct position is judged by the glider pilot according to the tug position on the canopy of the glider. NOT by the wings on the horizon...that doesn't work in mountains or bad weather! ! ! !

[gondukin]

Thanks for the feedback :) The tug was in sink as opposed to us deliberately descending. By the time I abandoned the launch, the tug was in fact climbing again and was moving up the canopy fairly rapidly (I was probably now in that bit of sink).

There's some good ideas there for exercises I can discuss and maybe practice with an instructor next week, weather permitting. I'll also have a chat about what really is "too high" - although I felt uncomfortably high, I'd already eased the stick forward, taking tension off the rope, and had the descending tug in sight.

[OpenCirrus619]

You'll know if you get too high, for the tug pilots comfort, on tow - you'll be pushing the rope :eek:

OC619