Accident Sequence
While en route to an unmanned offshore platform South Pass 38 in the Gulf of Mexico, the helicopter encountered deteriorating weather. The pilot estimated cloud ceilings of about 300 feet and visibility of about 1 mile, conditions below Air Logistics’ operating minimums of 500 feet and 3 miles. Despite having the option to divert, the pilot continued to the destination platform. About 1 mile from the platform, while maneuvering to reduce airspeed, the helicopter began an inadvertent descent and entered an aerodynamic buffet. The buffet was most likely caused by transverse flow effect, where unequal lift vectors between the front and rear portions of the rotor disc occur, combined with a reduction in lift vectors due to a tailwind. The pilot was unable to maintain control or stop the descent before water impact.
Flotation and Liferaft Systems
The helicopter was equipped with externally mounted floats, deployable via a trigger on the cyclic, and two externally mounted liferafts deployable by an interior T-handle near the pilot’s left leg or external T-handles on the skid cross bar. A placard was only mounted near the interior T-handle. The pilot did not attempt to activate the flotation system or liferafts before impact because he was preoccupied with recovering from the buffet. He provided no indication why he did not deploy the external liferafts using the internal T-handle after entering the water, despite training on external liferaft deployments. Air Logistics’ training and operating manual expected pilots to deploy floats before water impact but did not address expectations for water impact without float deployment. Lacking additional guidance, the pilot reverted to water survival training and immediately exited the helicopter.
Survival Efforts and Search
All occupants survived the impact, exited the helicopter, and inflated their lifejackets. The pilot could not reach the external liferaft T-handles on the skids and attempted to direct passengers to deploy the liferafts. However, no passenger briefing had been conducted, and passengers did not know liferafts were available or how to deploy them. The passengers and pilot swam toward the platform about 100 yards away but were separated by high waves and moved away by currents. At about 1551, an Air Logistics radio operator mistakenly recorded the helicopter as “landed,” delaying the overdue notification. About 34 minutes later, the error was discovered by the base manager because the pilot had not reported before sunset. A field boat was diverted but was too far away. Weather precluded launching a search helicopter. About 1 hour 15 minutes after the crash, a shrimp trawler crew retrieved two survivors and a deceased passenger from the water; the passenger died of hypothermia secondary to asphyxia from drowning. A Coast Guard ship rescued the severely hypothermic pilot more than four hours after the crash.
Post-Accident Safety Recommendations
On October 20, 2008, the NTSB issued two recommendations: A-08-83 asked for placards on each external T-handle for liferaft activation, and A-08-84 recommended including liferaft location and activation information in preflight safety briefings. Additionally, NTSB recommendation A-07-88 from 2007, asking the FAA to require beacon-equipped personal flotation devices for offshore helicopter crews, applied to this accident. In response, Air Logistics initiated a program providing pilots with lifejackets equipped with 406 MHz emergency position indicating radio beacons with two-way voice capability. Personal locator beacons were installed in liferafts, and water-activated switches for flotation systems and liferafts were being installed on Bell 407 helicopters. Placards were placed on aircraft undersides for manual deployment when inverted. Preflight briefing checklists, cards, and tapes were revised to include liferaft information. Training videos on flotation and liferaft deployment were produced and shown to passengers. To address misreporting, a senior company pilot now assists the radio operator, pilots must report every 30 minutes, and an extra keystroke confirms helicopter status.