Bell 206-L4 N266P accident near Mobile Block 114Cc

Probable cause

The pilot’s operation of the helicopter with a left, quartering headwind, resulting in conditions conducive to a loss of tail rotor effectiveness.

NTSB analysis

Shortly after liftoff from the production platform helideck, the pilot observed that the helicopter began an uncommanded slow yaw to the right. The pilot applied full left pedal, which had no effect. He lowered the collective, rolled the throttle to idle, and deployed the emergency floats. The helicopter impacted the water and rolled over. A postaccident examination of the wreckage did not reveal evidence of a mechanical malfunction or failure. Tail rotor system continuity was confirmed. The pilot reported that, just prior to the loss of directional control, there was a left, quartering headwind. This condition could have put 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.

Text from the NTSB. Open the NTSB docket for ERA11LA297 for the full record.