Accident Sequence
The pilot reported that as the aircraft touched down, the left main landing gear collapsed. He then performed an aborted landing. The tower reported that the landing gear appeared to be down. On the subsequent touchdown, the right main landing gear collapsed and the aircraft slid off the runway.
Examination Findings
Examination of the aircraft revealed a loose landing gear wiring block. When the throttle was retarded, the landing gear circuit breaker would pop, shutting off the hydraulic pump, the gear position lights, and the warning horn. When weight was placed on the gear, the absence of hydraulic pressure permitted the gear to collapse.
Background
This was the first flight after a non-recorded LORAN installation was performed.