airlines were stalling 747's and particularly were concerned about the loads on the horizontal tail due to the buffeting
As a DC-10 crew proved, bits fell off. From Wiki,
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 that 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 was 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 that 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 that 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 caused the airspeed to fall below the stall speed of the aircraft