The Aerotow
Since aerotowing is a form of formation flying, the sailplane pilot must maintain a proper position with respect to the tow plane at all times. Most aerotow is done in the High tow position. This means that the tow plane’s wheels appear that they are sitting on the horizon and that you are directly in line with the tow plane’s tail in straight and level flight. Only small control inputs are required to make corrections. When the student feels that they are wildly out of position, this usually translates into moving the aircraft only ten or fifteen feet which requires only modest amounts of bank (+/- 5 Degrees). Usually movements translate into little ‘S’ turns as it is important to start levelling the wings before you actually arrive at the central position behind the towplane. In a turn the student must understand that they are flying the tangent of a circle. When properly positioned the glider will appear to be flying towards the uter wingtip of the towplane. When attempting to follow the towplane in a turn, the key is to delay the turn entry. While the aerotow is formation flying, the glider is following the towplanes movements with a delay of a few seconds. When glider pilots delay following the towplanes movements the result is that can more accurately mimic the bank and the rate of the turn. We see this in our illustration. The towplane banks first (1,2). The glider pilot delays until the glider’s nose is about half way down the wing (3) and then matches the towplanes bank (4). When the towplane levels out (5) the glider stays banked until the proper position in the centre approaches and then levels out (6). Students will have a much easier time with the aerotow if they use this ‘delay then follow’ tactic. When things really go wrong the best advice is to level the wings in the current position, correct vertical position, and then the horizontal position. This has the advantage of giving the student less complicated manoeuvres and more time to do them.
At your release height, DON’T WAIT for the towplane to rock its wings asking you to release. That’s an emergency signal and tow pilots would much prefer that you get off when you are supposed to get off. If they do signal, release IMMEDIATELY. You should already have checked for traffic because you knew your release altitude was approaching. Sometimes it seems as if the tow plane is waving you off early. This is because, unlike a glider altimeter, a towplane’s engine vibration keeps the altimeter from sticking. At release a glider altimeter can read as much as 100 feet lower than the actual height.
Slack Rope
Glider pilots often fly in turbulent conditions, so the ability to recover
from slack rope is essential. The tow rope is designed to break to prevent
damage to either the towplane or the glider. However, this is not always when
turbulence or other factors cause the glider to get out of position and slack
develops in the towline. When trying to remove the slack, the idea is to create
some drag to slow down the glider, and then ease off the drag once the slack in
the line is taken up. Yawing the glider is a convenient way to do this, and the
least complicated from a control point of view. Severe cases may require the use
of spoilers.