The NTSB has recommended to the FAA that all U.S.-registered turbine helicopters certified to carry at least six passengers be required to have terrain awareness and warning systems (TAWS). The recommendation stems from the investigation of the crash of an Era Aviation Sikorsky S-76++ in the Gulf of Mexico, which killed all 10 people on board and destroyed the helicopter.
The Safety Board determined that the probable cause of the March 23, 2004, accident was the flight crew’s failure to identify and arrest the helicopter’s descent for undetermined reasons. NTSB acting chairman Mark Rosenker said TAWS “would have given the pilots enough time to arrest their descent and save the lives of all aboard.” He added, “It is well past time for the benefits from these standard safety devices to be made available to passengers on helicopter transports. More than two million passengers are carried on Gulf of Mexico oil industry operations alone.”
The helicopter was transporting Unocal oil workers from Galveston, Texas, to an offshore drilling ship, with a stop at a refueling platform in the Gulf. Weather was VFR but it was a dark night with few visual cues over the water. Since the helicopter was not equipped with a flight data recorder (FDR) and the cockpit voice recorder (CVR) was unintelligible because it was improperly installed, the Board could not determine the sequence of events. It concluded the pilots did not monitor the helicopter’s altitude as it descended into the water.
When the FAA required TAWS on airplanes carrying six or more passengers in 2000, the NTSB said, the technology was not available for helicopters, but it is available now. In 2003 the FAA exempted the S-76A and several other helicopters from the FDR requirement because it “would be in the public interest and would not adversely affect safety.” The Board disagreed: “Because the information that investigators learn from FDR data can help prevent accidents and incidents from recurring, the lack of FDRs…undoubtedly affects safety.”
In its March 7 release about the recommendations, the Board also urged that the FAA require FDRs on large commercial helicopters, as such information would have helped the investigation, as it had helped in the investigation of an FDR-equipped S-76 that crashed in Estonia. The Board said that CVRs should be checked before the first flight of the day and should undergo periodic maintenance checks. The NTSB also asked the FAA to improve flight following in areas such as the Gulf, where there is no radar coverage.