http://www.fss.aero/accident-reports...9-11-11-US.pdf
Precis: November 11, 1979 - an Aeromexico DC-10 entered a sustained stall while climbing through 29,800 ft, to its assigned cruise altitude of 31,000 ft, over Luxembourg, Europe. The flight crew failed to monitor their flight instruments, so they did not immediately recognize the plane was in a stalled condition. Instead, they blamed the heavy buffeting on the #3 engine, which they shut down, while continuing to hold the nose up. The plane continued to descend for one minute in a fully stalled condition, until the pilots lowered the nose and began a proper stall recovery procedure, which was completed at 18,900 ft. The #3 engine was then restarted, the declaration of emergency canceled and the flight continued to Miami, Florida. Ground inspection revealed four feet missing from each of the outboard elevator tips, including the balance weights. The NTSB concluded the sustained stall buffeting produced a dynamic structural overload on the elevator, which resulted in the failure of the elevator tips and balance weights. Further, the NTSB concluded the autopilot had improperly been placed in vertical speed mode. That forced the AP to keep increasing the angle of attack, to maintain the preselected vertical speed number, because maximum available engine thrust declined (normally) with increasing altitude. That in turn, caused the airspeed to fall below the stall speed of the aircraft.