I agree with Ramy, a fully laden ASG 29 is very intolerant of low tow speeds. As these wonderful gliders begin to fall into the hands les experienced, pilots it needs to become common knowledge that a heavy ASG 29 requires an extra 10 knots of airspeed from the tow plane. I have , and have seen two highly experienced friends struggle with control on takeoff in their 29’s.
We all had thermaling flaps deployed. This is especially true at high density altitudes. 80 knots works nicely. The tow pilot needs to be coached to hold the tow plane in ground effect until that speed is achieved. That can be unsettling to them, especially on hot days at high altitude, so the communication needs to be explicit. As others have said, some Pawnees have inaccurate pneumatics which can lead to pushback from the tow pilot. Any Standard class ship,when heavy, needs that same consideration.
Dale Bush