Re: That's about an inch of torque deflection every three feet or so. That sounds pretty high for high-strength steel.
This is one thing we need to fix if we want good spacecraft. Vehicles planetside (mainly air and sea ones) need to be able to flex so they can release or bend with the tremendous amounts of force being exerted upon them, but they do have limits. Spacecraft should not bend IN ANY WAY WHATSOEVER - doing so could rip the craft apart on reentry, compromise structural integrity, and open up leaks (I suppose they share those last two traits with submarines)
Come to think of it - What are the flex limits for subs?