What happened
On 30 April 2007, a Bell 206B Jet Ranger III, registration G-CODE, was performing a private flight in Bredbury, Stockport. After landing at a private field earlier that day, the pilot attempted to take off by first lifting into a hover and then performing a spot turn to the right. This maneuver was intended to align the aircraft with the wind to utilize the full length of the field for departure. During this turn, a sudden wind gust caused the aircraft to experience a loss of tail rotor effectiveness. The helicopter began spinning to the right for approximately one and a half rotations before the pilot could regain control. During the uncontrolled movement, a skid struck the ground, causing G-CODE to roll onto its right side. The impact resulted in one minor injury to a passenger, while the pilot remained unhurt. The aircraft sustained significant damage to the engine, fuselage, tail boom, transmission, gearbox, and main rotor blades.
The investigation
The investigation examined the flight conditions and the pilot's decision-making regarding the maneuver. It was noted that the pilot chose to turn to the right specifically to keep nearby power cables within his line of sight during the maneuver. Investigators found that the surface wind at the time was likely exceeding the aircraft's demonstrated limits for sideways and rearward flight. Specifically, while Manchester International Airport recorded winds of 16 knots gusting to 27 knots, the local wind at the accident site was estimated to have been even higher. The investigation also confirmed that the engine remained operational following the impact, though a fuel leak occurred.
Findings
- The primary cause of the accident was a sudden loss of tail rotor effectiveness triggered by a wind gust.
- The wind speeds at the accident site likely exceeded the maximum demonstrated sideways and rearward velocities for the Bell 206B Jet Ranger III.
- The pilot's decision to perform a right-hand spot turn, which involves reducing tail rotor thrust, contributed to the loss of control in the high-wind conditions.