Aircraft Accident/Incident Report

Jamaica Beach, Texas 77550
Tuesady, March 4, 1997 12:15 CST

During an offshore flight in the Gulf Of Mexico, approximately 3 nautical miles from San Luis Pass, the helicopter encountered low ceilings and low visibilities. The pilot began to slow the helicopter, and descended to approximately 50 above the water. He started a right turn to reverse direction while continuing to slow down. While in the turn, 'the aircraft began to vibrate and [he] recognized it as the transverse flow effect.' Due to the lack of resolution of the water, the pilot was having difficulty determining his exact altitude. He 'immediately applied collective and forward left cyclic to level the aircraft. The vibrations accelerated and the aircraft began an uncommanded turn to the right.' He followed the turn with cyclic and allowed the aircraft to descend. He rolled off the throttle, and the spin stopped. Before the pilot could inflate the floats, the helicopter impacted the water, rolled over onto its right side and subsequently sank. The raft was recovered from the helicopter, and the pilot and passengers floated in dense fog for about 3 1/2 hours before washing ashore at Surfside Beach.

The pilot's encounter with instrument meteorological conditions, and his subsequent loss of aircraft control due to the loss of visual cues to detect his height above the water. Factors were the low ceilings and fog, and the loss of tail rotor effectiveness.