Originally Posted by
Grebe
maybe not a spins- but a rotating dive from wiki
February 1959: Pan Am Flight 115, a Pan American World Airways Boeing 707, upset and went into a high-speed dive while cruising over the Atlantic at flight level350. Control was not recovered until reaching 6,000 ft. .... The Captain was in the cabin when the autopilot disconnected without adequate warning to the First Officer, who was distracted with a "howgozit" report form.
Maybe some relevance to the current situation. If in February 1959 the aircraft (in fact all jets) had only been in service for a few months, like the Max incidents. All the crew, despite prior experience, possibly only had 100 hours or so on type.