What happened
On 3 September 2001, a Westland Gazelle HT Mk3, registration G-BXZE, was performing a private flight departing from the western side of the International Arena at Hickstead Showground, West Sussex. While lifting off to a hover approximately 6 to 8 feet above the ground, the pilot initiated a left pedal turn to reposition the aircraft toward the eastern arena.
During this maneuver, the pilot experienced a sudden and rapid increase in the left turn rate that could not be arrested. The aircraft continued to rotate for approximately 10 to 12 full revolutions. To prevent further escalation, the pilot elected to land the helicopter immediately while the rapid leftward rotation was still in progress. Upon touchdown, the right skid of the Westland Gazelle HT Mk3 broke, and the aircraft sustained damage to the tail boom, tail fin, fenestron, and skids. The pilot successfully shut down the engine, though the right-side door had opened during the landing sequence.
The investigation
Investigators examined the aircraft and found no evidence of mechanical failure in the tail rotor transmission. While the fenestron fairing was buckled and showed signs that the tail rotor blades had contacted the interior of the fairing, this was determined to have likely occurred during the ground impact rather than during flight. There were no failures identified in the tail rotor blades.
An engineering assessment also noted that a main rotor blade had struck the corner of the right-side door. Maintenance records and inspections confirmed that the tail rotor transmission remained connected and functional. Meteorological data at the time indicated light winds from the west, with visibility exceeding 25 km.
Findings
- The primary cause of the incident was the rapid increase in left yaw rate following a left pedal input during a low-speed hover.
- The pilot's attempt to arrest the turn was insufficient to stop the rotation, leading to multiple full rotations before landing.
- The aircraft sustained damage to the skids, tail section, and fenestron due to the rotational deceleration and ground contact.
- Manufacturer documentation and service letters previously highlighted that the Gazelle series can experience high-rate left turns in hover or low-speed flight if the pilot does not apply immediate and significant right pedal input to counter the movement.