At 21:00 26 June 2005, Jj Sinclair wrote:

Is this what happened to Ivans and Egan?

That's Don Engen.

The accident reports indicated that the outer wing
panels departed following a (more or less) symmetric
pull-up, probably out of a spiral dive. It's unlikely
that there was much asymmetric twisting at work.

The twisting aeroelastic effect comes from high aileron
hinge moments associated with high speeds and large
control deflections. Happened to my Dad in an F-86
doing max-Q testing below sea level. It's less common
at glider speeds, but long, floppy wings might permit
it.

I consider it a good idea to execute the symmetric
maneuver (pull-up) before the asymmetric one (roll),
particularly at high speed. This helps to avoid JJ's
experience.

9B