What happened
On 12 June 1999, a Piper PA-30, registration F-BRUS, was participating in a private flight to Shoreham Airport. The aircraft was part of a large group of aircraft arriving from France. During the approach, the pilot noticed that the flaps were unresponsive and the cockpit lights had gone dark, suggesting a total electrical failure. Because the pilot could not confirm if the landing gear was locked, a go-around was performed.
During the subsequent approach, the aircraft's nose gear was observed to be partially retracted. Upon touchdown, the landing gear collapsed, causing one propeller to strike the runway. The aircraft briefly lifted off before settling again and sliding off the runway to the left. There were no fatalities and no injuries to the pilot or the passenger.
The investigation
Investigators examined the aircraft's electrical system and the pilot's actions following the initial failure. The pilot attempted to use the manual emergency gear extension system by rotating the landing gear torque tube with a lever. He noted that the physical resistance encountered while using the lever led him to believe the gear was already fully extended.
Further inspection of the aircraft's history revealed that at the start of the flight in Toussus-le-Noble, the pilot had found the alternator field switches in the 'OFF' position and moved them to 'ON'. The investigation also looked into the pilot's cockpit procedures during the flight, noting that the pilot was heavily occupied with navigating through poor weather conditions.
Findings
- The aircraft suffered a total electrical failure during the approach, which prevented the cockpit lights from indicating the landing gear status.
- The pilot did not perform individual alternator checks prior to takeoff or conduct standard cruise checks (FREDA) during the flight.
- The pilot's attempt to manually verify the gear position via the torque tube was based on an incorrect assumption that high resistance indicated the gear was locked.
- The landing gear collapse was caused by the nose gear not being fully extended at the moment of touchdown.