Bell 206L-3 N108PH incident near Gulf Of Mexico

Probable cause

A suspected failure of the tail rotor for undetermined reasons. A contributing factor was the failure of the emergency floats to properly inflate due to improper installment and inspection by maintenance personnel.

NTSB analysis

The pilot and his two passengers were in cruise flight over the Gulf of Mexico, when the pilot heard a "pop", and the single-engine helicopter suddenly pitched over and to the right. The pilot lowered the collective and stabilized the helicopter. The engine was running normally, but there was no response from the anti-torque pedals, and the pilot realized he had a possible tail rotor failure. He entered an autorotation and made a controlled landing on the top of a swell. As the helicopter settled, the pilot noticed that the center emergency float on the right side did not inflate and the helicopter rolled to the right. The pilot did not have time to activate the emergency life raft switch and exited the helicopter once it was fully inverted. While still under water, he inflated his life vest and immediately rose to the surface where he observed the two passengers. The three of them then held onto the skids of the helicopter and waited for a nearby boat to rescue them. While waiting for the boat, the pilot did a quick check of the helicopter and saw there was no damage to the underside of the tail boom.

During the rescue, a tug boat arrived on the scene and attempted to secure the helicopter with ropes and drag it to a nearby barge. It was during this attempt in rough seas that the tail boom and the aft portion of the left skid along with the attached aft float separated from the helicopter and were not recovered. The main body of the helicopter including the main rotor system and the engine were recovered. A postaccident examination of the float system revealed that the flexible hoses that supply Helium to the mid and aft floats on both the left and right skids were installed incorrectly (interchanged) which resulted in non-restricted air being delivered to the mid float and restricted air being delivered to the aft float. As a result, the right side center float burst due to excessive pressure and the aft float did not fully inflate.

Text from the NTSB. Open the NTSB docket for CEN10IA314 for the full record.