It's hard to believe that boxing the wake and slack line recoveries damaged the Pawnee. I fly both ends of the rope, tow and CFIG. The tubes holding the Schweizer hook and bolts would show damage before the lower tube weld cracks. I'd suspect hard tailwheel first landings on pavement, or pilots that land short in gravel and roll up onto a paved runway "over a lip" would cause more damage and flat tail wheels.

Our Pawnee saw crop duster service for 20+ yrs before converting to glider tow. The records show the entire lower fuselage frame has been rebuilt from corrosion over the years. It has been in a dry climate for the last 15 yrs..

Why do we box the wake? Why do we teach our teenage drivers how to parralle park. Because it shows you know where the corners of the car are and that you can "put it where you want it". Same with boxing the wake, same with boom limits when air refueling, you know where the limits are, you can control your aircraft throughout the entire envelope.

BillT