If you find one of your Condors is unstable in pitch, give me a shout.
Back in the seventies, I helped sort out one of Three Counties Condors which had a variable incidence wing ! The aircraft was occasionally snagged for being unstable on the approach but we all thought it was inexperience on the part of the student. Only after the CFI declared it unflyable did we look seriously for the problem and we were horrified to find the rear wing attachment bolts had worn slots in the fuselage frame due to incorrect torque loading. The wing trailing edge was moving up and down about 6 inches!!
The interesting thing is that it was used almost exclusively by one particular student who didn't like Cessna "tin-toys" and he thought that was the way it was meant to fly !