Incident Overview
A training flight conducting practice autorotations with power recovery resulted in an accident when the student pilot did not correctly initiate the flare. The certified flight instructor (CFI) did not intervene promptly, allowing the helicopter to inadvertently contact the taxiway surface. The aircraft bounced back into the air, at which point the CFI assumed control. However, due to low rotor rpm, the helicopter settled back onto the taxiway a second time.
Sequence of Events
The instructor then transitioned to a run-on landing. During this landing, one skid slid off the side of the runway and encountered soft terrain. The skid sank into the terrain, causing the helicopter to nose over.
Contributing Factors
The accident sequence began with the student's failure to properly execute the flare during the autorotation. The CFI's delayed intervention allowed the initial ground contact to occur. Subsequently, low rotor rpm prevented a successful recovery after the bounce, leading to the second touchdown and the eventual run-on landing that ended in the nose-over.
Conclusion
The mishap involved a series of events stemming from the student's flare error and the instructor's untimely intervention. The helicopter sustained damage from the ground contacts and the nose-over.