What happened
On December 16, 1999, a Piper PA-34-200 departed from Berlin-Schönefeld on a private flight bound for Riga. The crew, consisting of the pilot, a co-pilot, and one passenger, intended to begin the flight under VFR conditions before transitioning to IFR. Shortly after takeoff, while the landing gear was still in the process of retracting, the aircraft experienced a total electrical system failure.
After attempting to troubleshoot the issue by checking fuses and cycling the master and generator switches without success, the pilot decided to divert to Finow for an emergency landing. During the approach, the crew could only visually confirm via a mirror that the nose gear had been extended. However, the main landing gear had not been fully extended or locked. Upon touchdown, the partially extended gear failed to support the weight of the aircraft, causing the fuselage and propeller to make contact with the ground.
The investigation
The BFU examined the aircraft's electrical and mechanical systems following the accident. Post-accident testing revealed that the electrical system was functioning normally; both generators engaged at 1500 RPM, and all instruments operated correctly. Furthermore, the landing gear was found to be in good working order, as the gear could be extended and locked properly using the battery and the emergency system during subsequent functional tests.
Findings
- The investigation could not identify a mechanical defect in the landing gear, as the gear functioned perfectly once the aircraft was lifted from the ground.
- The cause of the electrical failure could not be reproduced. It was determined that the failure was either due to a non-reproducible electrical fault, such as a sticking relay, or an inadvertent error by the pilot, such as accidentally switching the master switch to the OFF position.
- The failure of the landing gear to lock during the emergency landing was likely due to the gear not being fully extended initially, which prevented the necessary momentum for the locking mechanism to engage.