What happened
The aircraft experienced an unexpected loss of engine power while airborne. In response to the emergency, the pilot attempted to restart the engine by engaging the starter motor while the propeller was windmilling due to airflow. Despite this effort, the engine did not recover power, necessitating a forced landing on the ground.
During the subsequent forced landing maneuver, the aircraft sustained significant structural damage. Specifically, the nose gear collapsed upon impact with the surface, indicating substantial force during touchdown or rollout. The pilot managed to bring the aircraft to a stop after the gear failure.
The investigation
Post-accident examination of the engine revealed critical mechanical failures within the starting system. Investigators found that the starter gear was completely shattered. Fragments of the starter gear teeth were scattered throughout various internal components of the engine, suggesting a violent mechanical disintegration during the attempted restart or prior to it.
Findings
The investigation focused on determining why the engine lost power initially and what caused the starter failure. However, despite the thorough inspection of the engine components, no definitive reason was identified for the original loss of engine power. The cause of the starter gear shattering remains unclear in relation to the initial power loss.
The collapse of the nose gear during the forced landing was a result of the impact forces rather than a pre-existing mechanical defect. No further contributing factors were identified beyond the unexplained engine power loss and the subsequent mechanical failure of the starter assembly.