What happened
During the landing phase of flight, the pilot reported that the left main gear collapsed as the aircraft touched down. Following this initial failure, the pilot attempted an aborted landing. Air traffic control tower personnel observed that the landing gear appeared to be in the down position. However, upon touchdown, the right main gear also collapsed, causing the aircraft to slide off the runway.
The investigation
An examination of the aircraft identified a loose landing gear wiring block. Investigators determined that when the throttle was retarded, the landing gear circuit breaker would pop. This action resulted in the loss of power to the hydraulic pump, the gear position lights, and the warning horn. As weight was applied to the landing gear during the landing sequence, the resulting absence of hydraulic pressure allowed the gear to collapse.
Findings
It was noted that this flight was the first operation conducted following a non-recorded LORAN installation.