Originally Posted by
MechEngr
To get a similar pull from a 20:1 L/D glider tow, the glider could weigh around 25,000 pounds.
I'm going to guess that you don't have much experience towing racing sailplanes with a full ballast load. I have and I assure you the limiting weight is an order of magnitude less than you propose.
What some people seem to be missing when commenting on this accident is the huge change in yaw stability when the banner was released. The tug went from being unspinnable to being very likely to spin as soon as the release was pulled. A contributing factor may be that some tow release handles are down on the floor and reaching for them may result in momentary loss of forward vision.
I've pulled lots of gliders but never a banner. Am I correct in thinking that a routine banner release is done well above stall speed and with far less than full power?