What happened
On 18 June 2000, a Robinson R22 helicopter, registered ZS-RAA, was conducting a private flight from Marble Hall toward Johannesburg. The pilot's intention was to deliver the aircraft to a maintenance facility at Grand Central the following morning. During the approach, while the airport was already in sight, the engine suddenly ceased functioning, forcing the pilot to initiate an autorotation.
In an attempt to avoid a collision with a line of trees, the pilot maneuvered the aircraft away from the obstacle. During this evasive action, the rotor RPM decayed significantly. Consequently, there was insufficient inertia remaining to arrest the aircraft's descent, resulting in a hard landing approximately 2nm from Grand Central. The pilot sustained one injury, but there were no fatalities.
The investigation
The investigation focused on the sudden loss of engine power during the final stages of the flight. Investigators examined the sequence of events leading from the engine failure to the impact, specifically looking at the pilot's maneuvers to avoid trees and the subsequent loss of rotor RPM. The investigation also reviewed the aircraft's fuel system and the circumstances surrounding the engine's failure.
Findings
- The primary cause of the engine failure was fuel starvation.
- The pilot's decision to maneuver away from trees to prevent a collision contributed to the decay of rotor RPM.
- The loss of rotor inertia prevented the pilot from successfully cushioning the descent, leading to the hard landing.