FTW97LA114

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.

On March 4, 1997, about 1215 central standard time, a Bell 206L-1 helicopter, N5829D, registered to Offshore Logistics, Inc., and operated by Air Logistics as a Title 14 CFR Part 135 non scheduled passenger flight, was destroyed in the Gulf Of Mexico, following an encounter with weather approximately 3 nautical miles east of San Luis Pass, near Jamaica Beach, Texas. Instrument meteorological conditions prevailed for the offshore flight, and a company VFR flight plan was filed. The airline transport rated pilot sustained minor injuries, and the four passengers were not injured. The flight originated from the Galveston 313 platform in the Gulf Of Mexico, about 9 minutes before the accident.

The pilot reported to the operator that company flight following (Galveston) advised him that his destination, Galveston, was "fogged in." He elected to continue inbound to Galveston, and when he was "3 or 4 miles from the beach," he encountered a "brown out" condition where he could not distinguish where the water ended and the horizon began. Due to the decreased visibility he descended to 250 or 300 feet MSL. He made a decision to turn around, and "started a slow right hand turn [while] continuing to slow down. At some point in the turn the aircraft began to settle." He was unable to lower the collective and "run out of the settling due to [the low] altitude." The aircraft "began to loose tail rotor effectiveness," and he was unable to fly out of the spin. He rolled off the throttle, and the spinning stopped. He misjudged his height above the water, and the aircraft impacted the water before he could inflate the floats.

The pilot reported in a written statement that prior to takeoff from the platform, the fog started "breaking up and the sun started coming out." He determined that the weather was flyable, and it met the company's weather minimums of 500 foot ceiling and 3 miles visibility. After takeoff, he contacted Galveston flight following to open a flight plan to Galveston, and flight following reported that Galveston was "fogged in." He advised flight following he "would fly to the beach as long as [he] could maintain company minimums, then along the beach and either land or get a special [VFR clearance] from Houston Center." While en route to the beach, he encountered low ceilings and low visibilities. He began to slow the helicopter and descended to 300 feet MSL. While in a right turn, "the aircraft began to vibrate and [he] recognized it as the transverse flow effect." Due to the lack of resolution of the water, he 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 to approximately 150 feet. He reduced the throttle, and the spin stopped. He made a decision to deploy the floats and perform a hovering autorotation to the water; however, before the floats could be inflated the helicopter impacted the water, rolled over onto its right side and subsequently sank.

One of the passengers reported in a written statement that they were en route to Galveston at an altitude of 300 feet. The weather "was foggy but [he] deemed flyable, with visibility of about 3 miles and the ceiling was about 500 feet." A few minutes into the flight, "the weather got foggier and the pilot turned on the windshield vents and dropped in altitude to about 250 feet." Within a few more minutes, they "had slowed down considerably, dropped in altitude and entered into a wall of fog that was the same color as the Gulf." The pilot told him "its time to turn around." They "were only about 50 feet above the water and proceeding ahead very slowly." As they turned to the right, the helicopter began to "spin in that same direction." After "about three spins (five max) I felt the power shut down." The helicopter "hit the water with the front of the right skid and immediately flipped upside-down and filled with water." After everyone was accounted for, he recovered the raft from the helicopter. The raft was inflated and they all got onboard. "They floated in dense fog for about 3 and 1/2 hours before washing ashore onto Surfside Beach."