What happened
The aircraft was engaged in a ferry flight, transporting itself from an offshore oil rig to the shore. During this transit, the tail rotor gearbox experienced a catastrophic failure and subsequently separated from the airframe. In response to the loss of anti-torque control, the pilot initiated an autorotation to maintain lift and control descent rate.
The pilot successfully guided the helicopter toward the water surface for a controlled ditching. Upon contact with the water, the aircraft rolled over due to the impact forces. Prior to the emergency landing, the pilot had communicated with his skipper via radio while descending from approximately 1,800 feet to establish a pickup position.
After the aircraft settled in the water, the pilot activated the emergency flotation devices. He then exited the helicopter and awaited rescue personnel. The pilot survived the incident without serious injury.
The investigation
Examination of the wreckage confirmed that the tail rotor gearbox had failed and detached from the main structure of the helicopter. This mechanical failure was the primary event leading to the loss of directional control during flight.
Findings
The sequence of events indicates a mechanical failure of the tail rotor system during ferry operations. The pilot's decision to autorotate to the water rather than attempt a forced landing on the rig or open sea allowed for survival. The deployment of floats and subsequent exit from the aircraft were executed correctly, facilitating rescue.
Safety message
This incident highlights the critical importance of emergency procedures in rotary-wing aircraft when anti-torque systems fail. Proper execution of autorotation techniques and familiarity with ditching protocols can significantly enhance survivability in offshore operations.