Crew Actions And Safety Equipment Credited With Saving
Passengers' Lives
The NTSB has issued its probable cause report for US
Airways flight 1549, in which a US Airways A320 jetliner bound for
Charlotte was ditched into the Hudson River after striking a flock
of Canada geese shortly after departing New York’s LaGuardia
Airport. All of the 150 passengers and five crewmembers
survived.
The NTSB determined that "the probable cause of this accident
was the ingestion of large birds into each engine, which resulted
in an almost total loss of thrust in both engines and the
subsequent ditching on the Hudson River. Contributing to the
fuselage damage and resulting unavailability of the aft slide/rafts
were (1) the Federal Aviation Administration’s approval of
ditching certification without determining whether pilots could
attain the ditching parameters without engine thrust, (2) the lack
of industry flight crew training and guidance on ditching
techniques, and (3) the captain’s resulting difficulty
maintaining his intended airspeed on final approach due to the task
saturation resulting from the emergency situation."
In addition to the decisions and actions of the flight
crewmembers, overwater safety equipment likely saved lives that
might have otherwise been lost to drowning, the NTSB said.
The board met Tuesday to conclude its 15-month investigation
into the January 15, 2009, accident.
Photo Credit Gregory Lam
Though it wasn't required on the New York to Charlotte flight,
the A320 was certified for Extended Over Water (EOW) operations,
meaning it carried forward slide/rafts and other specialized safety
gear. Investigators said that, had the airplane not been so
equipped, many of the 64 occupants of those rafts would likely have
been submerged in the 41-degree Hudson River, potentially causing a
phenomenon called “cold shock,” which can lead to
drowning in as little as five minutes.
Good visibility, calm waters, and proximity of passenger
ferries, which rescued everyone on flight 1549 within 20 minutes,
were other post-accident factors the Safety Board credited with the
survival of all aboard the aircraft.
“Once the birds and the airplane collided and the accident
became inevitable, so many things went right,” said NTSB
Chairman Deborah A.P. Hersman. “This is a great example of
the professionalism of the crewmembers, air traffic controllers and
emergency responders who all played a role in preserving the safety
of everyone aboard.”
Photo Credit Gregory Lam
The report adopted by the Safety Board Tuesday validated the
Captain’s decision to ditch into the Hudson River saying that
it “provided the highest probability that the accident would
be survivable.” Contributing to the survivability of the
accident was the crew resource management between the captain and
first officer, which allowed them to maintain control of the
airplane, increasing the survivability of the impact with the
water.
In addressing the hazards that birds pose to aircraft of all
sizes, the report noted that most bird strike events occur within
500 feet of the ground while flight 1549 struck geese at 2700 feet.
Investigators said that this difference demonstrates that
“bird strike hazards to commercial aircraft are not limited
to any predictable scenario.”
Concluding that engine screens or changes to design would not be
a viable solution to protect against bird ingestion events on
commercial jetliners, the Board made it clear that the potential
for significant damage from encounters with birds remains a
challenge to the aviation community.
Photo Credit Gregory Lam
As part of its extensive examination into the behavior of the
passengers and crewmembers from the time the plane left the gate at
LaGuardia to the moment the last person was rescued in the river,
the Board noted that since most of the passengers indicated that
they had not paid attention to the preflight oral safety briefing,
“more creative and effective methods of conveying safety
information to passengers” was needed. Survival factors
investigators also found that passengers had significant problems
in donning the life vests that were stowed under each seat.
The Board made 35 safety recommendations on engine and aircraft
certification standards, checklist design, flight crew training,
airport wildlife mitigation, cabin safety equipment, and preflight
passenger briefings.
“I believe the safety recommendations that have come out
of this investigation have an extraordinary origin -- a very
serious accident in which everyone survived,” said Chairman
Hersman (pictured). “Even in an accident where everyone
survives, there are lessons learned and areas that could use
improvement. Our report today takes these lessons learned so
that, if our recommendations are implemented, every passenger and
crewmember may have the opportunity to benefit from the advances in
safety.”
Among the other recommendations from the NTSB:
- Require manufacturers of 14 Code of Federal Regulations Part
25-certificated aircraft to develop a checklist and procedure for a
dual-engine failure occurring at a low altitude.
- Require 14 Code of Federal Regulations Part 121, Part 135, and
Part 91 Subpart K operators to include a dual-engine failure
scenario occurring at a low altitude in initial and recurrent
ground and simulator training designed to improve pilots’
critical-thinking, task-shedding, decision-making, and
workload-management skills.
- Require Airbus operators to amend the ditching portion of the
Engine Dual Failure checklist and any other applicable checklists
to include a step to select the ground proximity warning system and
terrain alerts to OFF during the final descent.
- Require Airbus operators to expand the
angle-of-attack-protection envelope limitations ground school
training to inform pilots about alpha-protection mode features
while in normal law that can affect the pitch response of the
airplane. Require applicants for aircraft certification to
demonstrate that their ditching parameters can be attained without
engine power by pilots without the use of exceptional skill or
strength.
- Require, on all new and in-service transport-category
airplanes, that cabin safety equipment be stowed in locations that
ensure that life rafts and/or slide/rafts remain accessible and
that sufficient capacity is available for all occupants after a
ditching.
- Require Airbus to redesign the frame 65 vertical beam on A318,
A319, A320, and A321 series airplanes to lessen the likelihood that
it will intrude into the cabin during a ditching or gear-up landing
and Airbus operators to incorporate these changes on their
airplanes.
The NTSB also recommends that the U.S. Department of Agriculture
"(d)evelop and implement, in conjunction with the Federal Aviation
Administration, innovative technologies that can be installed on
aircraft that would reduce the likelihood of a bird strike."