I always thought that was impossible considering that planes are designed to seek stability. The common belief was that it takes a pilot to overstress the hull/wings. But then in the last issue of FLYING mag Peter Garrison describes accident when pilot died of hypoxia during flight and the plane spiraled down from 27,000 ft and broke apart while still in the air. There was a female passenger in the aircraft ... who survived landing ... in a hickory tree .. but this is yet another story.It was a twin engine Cessna Skymaster.Michael J.

I read that article, but I thought they had flown into a thunderstorm cloud.