What happened
On December 11, 2001, at approximately 13:25 UTC, a Hughes 269C helicopter was conducting a dual instruction flight at Stockerau Airfield in Lower Austria. The flight, operated by a flight school, was being conducted using dual controls with a flight instructor and a student pilot.
While performing a hover at an altitude of approximately 2 to 3 meters above the ground, the student pilot applied excessive left pedal input. This initiated a leftward rotation around the vertical axis that the student was unable to arrest. As the instructor attempted to intervene using the right tail rotor pedal to stop the rotation, the right pedal broke at the location of the attachment pin bore.
Following the failure, the instructor took command of the aircraft, signaling "My control" to the student. The instructor then initiated an emergency landing. However, the aircraft continued to rotate leftward and struck the ground with significant force. The impact left a counter-clockwise track in the snow covering the airfield. Both occupants were wearing seatbelts and were able to exit the aircraft on their own.
The investigation
The investigation reconstructed the sequence of events based on statements from the occupants and physical evidence at the scene. Investigators noted that the tail rotor skid and vertical stabilizer left a distinct track in the snow, confirming the continuous leftward rotation until impact. The instructor reported that the failure of the right pedal did not involve any unusual resistance prior to the breakage. The student pilot confirmed that they did not interfere with or block the instructor's control inputs following the transfer of command.
Findings
- The primary cause of the loss of directional control was the mechanical failure of the right tail rotor pedal, which broke at the attachment pin bore.
- The incident was preceded by an excessive left pedal input by the student pilot, which initiated the uncontrolled rotation.
- The aircraft sustained fatal/injury count: 0 fatalities and 1 light injury (the instructor sustained a minor head injury against a metal fitting on the door frame during egress).
- The Hughes 269C was destroyed in the crash.