Incident Overview
During the landing roll, the left main landing gear collapsed, and the aircraft veered off the runway, resulting in additional damage to the aircraft.
Investigation Findings
An investigation revealed that the left main landing gear trunnion had failed. The failure occurred diagonally approximately 5 inches from the bottom of the trunnion and 2 inches below the rotating axis. A metallurgical examination determined that preexisting fatigue was present at the fracture location.
The trunnion had been in service for approximately 4081 hours of operation.
Service Bulletin and Inspection History
Piper Service Bulletin #787A, dated August 15, 1985, addressed the possibility of cracks developing in the area where the failure occurred. The bulletin recommended that after the first 1000 hours in service, trunnions be inspected at intervals not to exceed 100 hours until replacement.
The last annual inspection of the aircraft was dated March 8, 1988, but there was no logbook entry indicating that the trunnion inspections had been completed. The aircraft had flown only 4 hours since the last inspection.