Could this be a problem or it is normal!!!

[GAHorn]

.... I've never heard of the horiz stab leading edge problem, that must have been taken care of before it reached production airplanes.

It was after the 195 assy-line was moved to a different location. The first airplane off the line was delivered to the customer who returned it after a scare. WD and another test pilot took it up and nearly lost it when it spun down, completely out of control, thru almost 10-thousand feet. He was about to bail out when it recovered by itself. The leading edge error was discovered due to a jig set-up error caused by the relocation and wear of the jigs.

He mentions Mort in the early chapters of his book, but ordinarily they did not work together as he was in engineering and Mort was in production-test. The curiosity to me is why production-test didn't catch the problem before a customer nearly killed himself. Makes me think not all production airframes were stall-tested (or some of them slipped thru without full testing.)

And it is one reason that, despite my full-confidence in the integrity of my airplane's restoration, I've never deliberately spun it. I had never realized that such minor problems could cause an unrecoverable spin, despite my own training as a production test-pilot. (Of course, my test-training was not in aircraft certified for spins so that was not part of the curriculum.)

[hilltop170]

Mort told a story about a similar spin incident in the 195 but it was a test aircraft. Unable to recover after trying everything, the door was jettisoned so the pilots could bail out and that's when the spin abruptly stopped and they landed safely but no one ever spun another one. The door on a production aircraft does not jettison.

If that was the same incident morphed over time, it would explain why production test did not discover it.

I used to spin my 170A a lot back in the 1970s and 1980s just for fun. It did exhibit weird tendencies spinning to the right though. Instead of the nose dropping and turning as per normal when spinning left, to the right with flaps down, it would rotate almost level for 1/2 turn then go inverted and into the spin. Kinda took my breath away the first time it did that but eventually it was fun, especially when I took another pilot who was used to spins up for the first time who had no idea what was about to happen. I only would spin it if the other person was in agreement but you would be surprised at how many folks never had spun to the right.

Then Del at Mountain Airframes discovered my wings were way out of whack and had been since 1952. I haven't spun it since the rebuild but might expect the characteristics might be a little different.