Incident Overview
While en route, the aircraft's ammeter dropped to zero, followed by a complete electrical failure. The landing gear warning horn and indicator lights became inoperative. Prior to landing, the pilot attempted to lower the landing gear using the freefall procedure, as recommended. During the landing roll, the right main landing gear collapsed, resulting in damage to the aircraft.
Sequence of Events
The electrical failure began with the ammeter reading zero, indicating a loss of charging system output. Subsequently, all electrical power was lost. The landing gear system, which relies on electrical power for normal operation and indications, became non-functional. The pilot followed the emergency procedure by releasing the landing gear to freefall, which uses gravity to extend the gear. However, upon touchdown, the right main gear failed structurally.
Examination Findings
A post-incident examination revealed that the alternator drive belt had failed, preventing the alternator from charging the battery. The aircraft battery had become fully discharged, rendering electrical systems inoperative. When an external power source was connected on the ground, the landing gear and indicator lights functioned properly, confirming that the electrical failure was the root cause of the gear system malfunction. No other mechanical issues were identified.