On August 4, 1983, Pan American World Airways Flight PA 073, a Boeing 747-100 (Reg. No. N738PA), veered off Runway 25R while landing at Karachi International Airport. The aircraft ran into soft earth, sustaining damage beyond economical repair (a hull loss). All 227 passengers and 16 crew members evacuated safely without injury. The investigation determined that while the No. 4 engine thrust reverser was known to be inoperative and deactivated, the pilot inadvertently applied forward thrust to that engine while stowing the reversers on engines 1, 2, and 3. This created an asymmetric power condition that the crew failed to recognize or monitor, leading to the runway excursion.
