NTSB has called on the
FAA to require all U.S.-registered turbine-powered helicopters
certificated to carry at least 6 passengers to be equipped with a
terrain awareness and warning system. The recommendation is
one of five contained in the final report of a fatal helicopter
accident in the Gulf of Mexico.
On March 23, 2004, an Era Aviation Sikorsky S-76A++ helicopter
(file photo, below), N579EH, crashed into the Gulf of Mexico at
about 7:18 p.m., 70 nautical miles south-southeast of Galveston,
Texas. Although visual meteorological conditions existed, it was a
dark night with very few external visual cues. The aircraft was
transporting eight oil service personnel to the Transocean drilling
ship Discoverer Spirit; they and the two pilots perished in the
crash.
The Board determined that the probable cause of the accident was
the flight crew's failure to identify and arrest the helicopter's
descent for undetermined reasons, which resulted in controlled
flight into the water.
"A terrain warning system would have given the pilots enough
time to arrest their descent and save the lives of all aboard,"
NTSB Acting Chairman Mark V. Rosenker said.
"It is well past time for the benefits from these standard
safety devices to be made available to passengers on helicopter
transports as they are on fixed wing planes. More than 2 million
passengers are carried on Gulf of Mexico oil industry operations
alone."
The aircraft was not
equipped with a flight data recorder, and the cockpit voice
recorder was improperly installed, rendering the recording almost
unusable. The Board, therefore, could not determine the sequence of
events that led to the helicopter's inadvertent descent. However,
since cockpit instrumentation was available to the pilots, the
Board concluded that the flight crew was not adequately monitoring
the helicopter's altitude and missed numerous cues to indicate that
the aircraft was descending toward the water.
The Board noted that when the FAA required TAWS (terrain
awareness and warning system) for airplanes having 6 or more
passengers in 2000, the technology had not been developed for the
unique characteristics of helicopter flight. However, TAWS
technology is now available for helicopter flight and should be
required, the Board said.
In 2003, the FAA exempted S-76A and several other helicopter
models from its requirement that they be equipped with flight data
recorders. In an earlier letter to Era, the FAA had stated that
exempting the helicopters from the FDR requirement "would be in the
public interest and would not adversely affect safety."
The Board disagreed with that assessment, stating, "because the
information that investigators learn from FDR data can help prevent
accidents and incidents from recurring, the lack of FDRs aboard
helicopters undoubtedly affects safety."
The NTSB noted that it had participated in the investigation of
another S-76 helicopter crash in Estonia. This was the first
accident known to involve a large helicopter for which FDR data was
available. Those data were extremely valuable to investigators, the
Board said. The lack of FDR data significantly hampered the Era
investigation, the Board said, and it urged the FAA to require FDRs
on commercial helicopters such as the one involved in the Gulf of
Mexico crash.
The Board also recommended that cockpit voice recorders on
aircraft be functionally checked before the first flight of each
day and that a periodic maintenance check be accomplished as part
of the approved maintenance check of the aircraft.
Other recommendations to the FAA dealt with expedited
implementation of an initiative to improve flight following where
traditional radar coverage doesn't exist, such as in portions of
Alaska and the Gulf of Mexico, and with proper training for certain
flight control systems.
The entire accident report will appear on the website in several
weeks.