The experiment with a flat stall was experienced by a Velocity aircraft. The aircraft had an aft cg and went into a stall. The plane fell tail first and all survived. But because of the aft cg, it could not recover. The engine maintained thrust and allowed a survivable crash.
To rectify the problem experimentation was done with a weight on a screw that allowed the cg to be adjusted aft during flight. Velocity fixed the aft cg problem and thus far I am not aware of this ever happening again. I think it was sport aviation. They showed pictures with the aircraft mounted on top of a truck to simulate flight. Peter O. Sanchez, Jr. KR2S in Apache Junction AZ
