What happened
During the initial phase of the takeoff roll, the left main landing gear assembly collapsed unexpectedly. This structural failure caused the aircraft to veer sharply off the runway surface, resulting in additional damage to the airframe.
The investigation
A thorough examination of the wreckage revealed that the left main landing gear trunnion had experienced a complete fracture. The break occurred diagonally at a specific location approximately 5 inches from the bottom of the trunnion and 2 inches below the rotating axis.
Metallurgical analysis of the failed component confirmed the presence of preexisting fatigue cracks at the site of the fracture. The trunnion had accumulated approximately 4,081 hours of service time prior to the incident. Piper Service Bulletin #787A, issued on August 15, 1985, addressed the potential for crack development in this specific area. The bulletin recommended that after the first 1,000 hours of service, trunnions be inspected at intervals not exceeding 100 hours until replacement.
Records indicated that the last annual inspection was dated March 8, 1988. However, there was no logbook entry confirming that the required inspections had been completed. The aircraft had flown only 4 hours since the date of that last recorded inspection.