Accident Narrative
On May 13, 2011, at about 1120 central daylight time, a Bell 206L-4 helicopter (registration N266P) landed in the Gulf of Mexico near the Mobile Block 114CC helideck following an in-flight loss of directional control. The helicopter, registered to and operated by PHI, Inc., was conducting a passenger flight under 14 CFR Part 135. Visual meteorological conditions prevailed, and a company visual flight rules flight plan was filed. The two pilots sustained serious injuries, while the passenger was not injured. The flight was originating at the time of the accident.
According to the operator, the pilot positioned the helicopter for a west-southwest departure due to prevailing wind conditions. After clearing the edge of the production platform helideck, the helicopter began a slow yaw to the right. The pilot applied full left pedal, but the rotation did not stop. After 360 degrees of rotation, the rotation quickened. The pilot stated that he "didn't have a tail rotor," lowered the collective, and rolled the throttle to idle. The pilot deployed the emergency floats, and the helicopter impacted the water slightly nose low and in a right drift. The helicopter rolled over immediately to the right and stayed afloat. The pilot egressed through the broken windscreen area, the left seat pilot egressed through the pilot's open door, and the passenger egressed through the left passenger door.
Wreckage Examination
The wreckage was recovered to PHI, Inc.'s facilities in Lafayette, Louisiana, where an examination was performed on May 18, 2011. An inspector from the Federal Aviation Administration (FAA) provided oversight, assisted by the operator and an investigator from Bell Helicopter. Examination of the engine, tail rotor gearbox, tail rotor drive shaft, main gear box, and main rotor system revealed no evidence of a pre-existing mechanical malfunction or anomaly. All long tail rotor drive shaft segments were connected. The tail rotor gear box was manually turned, and drive shaft continuity was verified. Rotational scoring was noted on the tail boom surface in the area of the tail rotor blades. No unusual noise was heard when the tail rotor gear box was rotated in both directions. The tail rotor pedals moved freely in both directions with no binding.
Pilot Interview
FAA inspectors conducted an interview with the pilot after the accident. The pilot reported that, immediately prior to the loss of directional control, the winds were coming from the left front quarter of the helicopter. The FAA inspector noted that this wind direction would have placed the helicopter in an area of main rotor disc interference with the tail rotor, which could have resulted in a loss of tail rotor effectiveness.