On March 23, 2004, about 1918:34 central standard time, an Era Aviation Sikorsky S-76A++ helicopter, N579EH, crashed into the Gulf of Mexico about 70 nautical miles south-southeast of Scholes International Airport (GLS), Galveston, Texas. The helicopter was transporting eight oil service personnel to the Transocean, Inc., drilling ship Discoverer Spirit, which was en route to a location about 180 miles south-southeast of GLS. The captain, copilot, and eight passengers aboard the helicopter were killed, and the helicopter was destroyed by impact forces. The flight was operating under the provisions of 14 Code of Federal Regulations Part 135 on a visual flight rules flight plan. Night visual meteorological conditions prevailed at the time of the accident.
The National Transportation Safety Board determines that the probable cause of this accident was the flight crew's failure to identify and arrest the helicopter's descent for undetermined reasons, which resulted in controlled flight into terrain.
The safety issues discussed in this report focus on terrain awareness and warning systems for helicopters, flight control system training, flight-tracking technology for low-flying aircraft in the Gulf of Mexico, and preflight testing and maintenance checks for cockpit voice recorders. Safety recommendations concerning these issues are addressed to the Federal Aviation Administration.
As a result of the investigation of this accident, the National Transportation Safety Board makes the following recommendations to the Federal Aviation Administration:
Require all existing and new U.S.-registered turbine-powered rotorcraft certificated for six or more passenger seats to be equipped with a terrain awareness and warning system. (A-06-19)
Ensure that all operators of helicopters equipped with either the SPZ-7000 or SPZ-7600 dual digital automatic flight control systems provide training that includes information on flight director and coupling status annunciations; the command cue presentations when only the pitch or the roll mode is engaged; and, if applicable, the differences between the SPZ-7000 and the SPZ-7600. (A-06-20)
Ensure that the infrastructure for the National Automatic Dependent Surveillance-Broadcast Program in the Gulf of Mexico is operational by fiscal year 2010. (A-06-21)
Until the infrastructure for the National Automatic Dependent Surveillance-Broadcast Program in the Gulf of Mexico is fully operational, require principal operations inspectors of Gulf of Mexico aircraft operators to inform the operators about the benefits of commercial flight-tracking systems and encourage the operators to acquire such systems. (A-06-22)
Require all operators of aircraft equipped with a cockpit voice recorder (CVR) to (1) test the functionality of the CVR before the first flight of each day as part of an approved aircraft checklist and (2) perform a periodic maintenance check of the CVR as part of an approved maintenance check of the aircraft. The CVR preflight test should be performed according to procedures provided by the CVR manufacturer and should include listening to the recorded signals on each channel to verify that the audio is being recorded properly, is intelligible, and is free from electrical noise or other interference. The periodic maintenance check of the CVR should include an audio test followed by a download and review of each channel of recorded audio. The downloaded recording should be checked for overall audio quality, CVR functionality, and intelligibility. (A-06-23)
Additional Recommendations Resulting From This Accident Investigation
As a result of the investigation of this accident (and the August 2005 accident involving the S-76C helicopter that crashed in the Baltic Sea shortly after takeoff),123 the Safety Board issued the following recommendations to the FAA on March 7, 2006:
Require all rotorcraft operating under 14 Code of Federal Regulations Parts 91 and 135 with a transport-category certification to be equipped with a cockpit voice recorder (CVR) and a flight data recorder (FDR). For those transport-category rotorcraft manufactured before October 11, 1991, require a CVR and an FDR or an onboard cockpit image recorder with the capability of recording cockpit audio, crew communications, and aircraft parametric data. (A-06-17)
Do not permit exemptions or exceptions to the flight recorder regulations that allow transport-category rotorcraft to operate without flight recorders, and withdraw the current exemptions and exceptions that allow transport-category rotorcraft to operate without flight recorders. (A-06-18)
Previously Issued Recommendation Classified in This Report
Safety Recommendation A-02-25 (previously classified "Open-Acceptable Response") is classified "Closed-Superseded" as a result of the issuance of Safety Recommendation A-06-23.