Event Details
While en route in instrument meteorological conditions (IMC), the aircraft suffered a complete electrical failure. The pilot responded by descending to visual flight rules (VFR) conditions and chose to land at Weiser Airport.
Emergency Landing and Gear Extension
Upon approaching the airport, the pilot lowered the landing gear electrically but did not receive a green down-and-locked indication. He then operated the emergency extension handle to manually pump the gear down; however, he still did not obtain a green down-and-locked indication. During the subsequent landing, the main landing gear retracted.
Manual Pumping Note
The investigation noted that had the pilot continued to manually pump, the gear would have locked down.
Investigation Findings
Examination revealed that the alternator fan blade had separated and exited through the engine cowling. The resultant vibration caused the alternator ground wire to separate from its attachment point, leading to the total electrical failure.