What happened
The aircraft was reportedly operating an air taxi cargo flight for Air Express out of Hayward, California. The flight departed Reno, Nevada, without filing a flight plan, with destinations listed as Sacramento and then Hayward. During the en route portion of the trip, the pilot experienced a sudden electrical failure.
In response to the malfunction, the pilot shut down all non-essential electrical systems. As the aircraft approached Travis Air Force Base, he powered on one radio transmitter and requested a partial approach to land. While receiving vectors from air traffic control, the pilot lost radio contact entirely. Unable to continue the approach or communicate with controllers, he elected to execute an emergency landing on a nearby road.
During the landing roll, the right wing of the aircraft struck a telephone pole. Weather conditions at Travis AFB at the time were poor, consisting of a 400-foot overcast ceiling and visibility of one and three-quarter miles in fog.
The investigation
A subsequent physical examination of the aircraft revealed significant issues with the electrical system. Investigators found that the right generator armature lead had been removed and was insulated from any electrical contact. Additionally, the left generator armature lead had broken loose from its connection point.
These mechanical failures resulted in a complete loss of power generation. Consequently, the aircraft battery became fully discharged, leading to the total electrical failure experienced by the pilot during flight. The operator did not submit an accident report, so the specific type of operation is presumed based on available records.
Findings
The primary factors contributing to this incident were the disconnection of the left generator armature lead and the removal of the right generator armature lead. These maintenance issues caused a total electrical system failure. The pilot's decision to land on a road was necessitated by the loss of radio contact and the inability to complete a standard instrument approach in foggy conditions.
Safety message
Proper maintenance of generator connections is critical for flight safety. Failure to secure armature leads can lead to total electrical failure, leaving the aircraft without power generation or communication capabilities.