“This investigation highlights the importance of following standard operating
procedures and underscores the significance of procedural compliance,” said
NTSB Vice Chairman Bella Dinh-Zarr. “Complacency does not have a place in the
cockpit of any aircraft.”
At 9:40 pm EDT on May 31, 2014, a Gulfstream G-IV business jet bound for
Atlantic City crashed after it overran the end of runway 11 during a rejected
takeoff at Laurence G. Hanscom Field in Bedford, Massachusetts. The airplane
rolled through the paved overrun area; continued across a grassy area, striking
approach lights and an antenna; and traveled through the airport fence before
coming to rest in a ravine. A postcrash fire engulfed the airplane almost
immediately. Everyone aboard – two pilots, a flight attendant and four
passengers – were killed.
During the engine start process, the flight crew failed to disengage the
airplane’s gust lock system, which locks the primary flight control surfaces
while the plane is parked to protect them against wind gusts.
The flight data recorder and cockpit voice recorder indicated that neither of
the two flight crewmembers, who had flown together for about 12 years, had
performed a basic flight control check that would have alerted them to the
locked flight controls. A review of the flight crew’s previous 175 flights
revealed that the pilots had performed complete preflight control checks on
only two of them. The flight crew’s habitual noncompliance with checklists was
a contributing factor to the accident.
“This investigation raises troubling questions about how a long-term pattern of
noncompliance was allowed to develop for this very experienced flight crew,”
Dinh-Zarr said. “More importantly, our investigation asks whether this is a
prevalent practice in the business aviation community, and how we can prevent
these accidents from happening again.”
About 26 seconds into the takeoff roll, when the airplane had reached a speed
of 148 mph (129 kts), the pilot in command indicated that the flight controls
were locked, but the crew did not begin to apply the brakes for another 10
seconds and did not reduce engine power until four more seconds had passed. The
NTSB determined that if the crew had rejected the takeoff within 11 seconds of
the pilot’s comment, the airplane would have stopped on the paved surface and
the accident would have been avoided.
The G-IV gust lock system design was intended to limit the operation of the
throttles when the system was engaged so that the flight crew would have an
unmistakable warning that the gust lock was on should the crew attempt to take
off. However, the investigation revealed that Gulfstream did not ensure that
the gust lock system would sufficiently limit the throttle movement on the G-IV
airplane, which allowed the pilots of the accident flight to accelerate the
airplane to takeoff speed before they discovered that the flight controls were
The NTSB said that the Federal Aviation Administration’s certification of the
gust lock system was inadequate because it did not require Gulfstream to
perform any engineering certification tests or analysis of the G-IV gust lock
system to verify that the system had met its regulatory requirements.
Also contributing to the accident were Gulfstream’s failure to ensure that the
gust lock system would prevent an attempted takeoff with the gust lock engaged
and the FAA’s failure to detect this inadequacy during the G-IV’s
As a result of the investigation, the NTSB issued a total of five safety
recommendations to the FAA, the International Business Aviation Council and the
National Business Aviation Association.
In addition, the NTSB developed a Safety Alert for all pilots on the importance
of following standard operating procedures and using checklists to guard
against procedural errors.
A synopsis of the accident along with the findings, probable cause and safety
recommendations are available at http://go.usa.gov/3MVQd
The opening and closing statements, presentations and accident animation from
today’s meeting are all available at http://go.usa.gov/3MVUm
A PDF of the complete accident report along with the Safety Alert will be
available on the NTSB website in several weeks.