What happened
On the evening of 2 February 1999, a Piper PA-30, registration G-BAWU, departed Exeter Airport for a local night flight. Shortly after takeoff, once a positive rate of climb was established, the pilot moved the landing gear selector to the up position. This action triggered an immediate failure of the aircraft's electrical system, resulting in the loss of cockpit lighting and radio communications.
In response to the darkness and loss of power, the crew attempted to manually extend the landing gear using the emergency procedure. This process involved accessing a panel between the seats to manipulate a release lever designed to disconnect the electric motor drive from the torque tube, allowing the gear to free-fall and then be manually locked into place. After performing the procedure, the crew felt and heard a physical indication that the gear was locked.
Although electrical power partially returned, the cockpit indicators failed to show the gear as down and locked. To verify the status, the crew performed a low flypast over the Exeter Tower. The controller, despite the difficulty of the dark conditions, reported that the nose gear appeared extended. Relying on this visual confirmation, the pilot proceeded with a standard approach. However, upon touchdown, the landing gear collapsed, causing the aircraft to slide to a halt on the runway. There were no injuries to the two crew members or two passengers.
The investigation
Investigators examined the aircraft and the maintenance history of the landing gear mechanism. A post-accident inspection by the maintenance organization suggested that the main landing gear had likely not been fully extended, noting that the gear doors remained undamaged. While the release lever had been raised, the internal sleeve had not slid forward to release the linkage. However, the investigation found severe distortion in the motor linkage, suggesting some rotation had occurred while the shaft was still engaged.
Testing of the aircraft in daylight revealed that the emergency release lever required a specific technique—pushing past a resistance point and rocking the lever side to side—to successfully release the sleeve. This specific operational requirement was notably absent from the aircraft's Flight Manual.
Regarding the initial electrical failure, the investigation looked into the aircraft's DC generator system. It was determined that the battery likely became depleted due to the electrical load of pre-flight checks, engine starting, and taxiing. When the landing gear motor was engaged, the resulting current draw caused the battery relay to trip, cutting power to the aircraft's systems.