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PB97-910401 NTSB/AAR-97/01
NATIONAL TRANSPORTATION SAFETY BOARD
WASHINGTON, D.C. 20594
AIRCRAFT ACCIDENT REPORT
WHEELS-UP LANDING
CONTINENTAL AIRLINES FLIGHT 1943
DOUGLAS DC-9 N10556
HOUSTON, TEXAS
FEBRUARY 19, 1996
EXECUTIVE SUMMARY
On February 19, 1996, at 0902 Central Standard Time, Continental
Airlines (COA) flight 1943, a Douglas DC-9-32, N10556, landed
wheels up on runway 27 at the Houston Intercontinental Airport,
Houston Texas. The airplane slid 6,850 feet before coming to rest
in the grass about 140 feet left of the runway centerline. The
cabin began to fill with smoke, and the captain ordered the evacuation
of the airplane There were 82 passengers, 2 flightcrew members,
and 3 flight attendants aboard the airplane. No fatal or serious
injuries occurred; 12 minor injuries to passengers were reported.
The airplane sustained substantial damage to its lower fuselage.
The regularly scheduled passenger flight was operating under Title
14 Code of Federal Regulations Part 121 and had originated from
Washington National Airport 3 hours before the accident. An instrument
flight rules flight plan had been filed; however, visual meteorological
conditions prevailed for the landing in Houston.
The National Transportation Safety Board determines that the probable
cause of this accident was the captain's decision to continue
the approach contrary to COA standard operating procedures that
mandate go-around when an approach is unstabilized below 500 feet
or a ground proximity warning system al continues below 200 feet
above field elevation. The following factors contributed to the
accident: (1) the flightcrew's failure to properly complete the
in-range checklist, which resulted in a lack of hydraulic pressure
to lower the landing gear and deploy the flaps; (2) the flightcrew's
failure to perform the landing checklist and confirm that the
landing gear was extended; (3) the inadequate remedial actions
by COA ensure adherence to standard operating procedures; and
(4) the Federal Aviation Administration's (FAA) inadequate oversight
of COA to ensure adherence to standard operating procedures.
Safety issues discussed in this report include checklist design,
flightcrew training, adherence to standard operating procedures,
adequacy of FAA surveillance, and flight attendant tailcone training.
Safety recommendations concerning these issues were made to the
FAA.
CONCLUSIONS
Findings
- The two-member flightcrew and three flight attendants were
trained and qualified to conduct the flight accordance with Federal
regulations. There was no evidence of any medical condition that
might have affected the flightcrew's performance.
- The air traffic control request to maintain 190 knots to the
outer marker did not contribute to the accident because it did
not affect crew actions, decisionmaking, or situational awareness.
- The airplane was certificated and equipped and maintained
in accordance with Federal regulations approved procedures. There
is no evidence that mechanical malfunctions or failures of the
airplane structures, flight control systems, or powerplants contributed
to the accident.
- Because the captain omitted the "Hydraulics" item
on the in-range checklist and the first officer failed to detect
the error, hydraulic pressure was not available to lower the landing
gear and deploy the flaps.
- The "Hydraulics" item is placed too low on the in-range
checklist, rendering it vulnerable to omissions.
- The captain's distraction from his duties as pilot-in-command
and his disregard for the sterile cockpit rule contributed to
the pilots' failure to detect their hydraulic system configuration
error when they selected 5º of flaps.
- Both the captain and the first officer recognized that the
flaps had not extended after the flaps were selected to 15º.
- The pilots' lack of previous exposure, either through training
or during line operations, to the consequences of improper hydraulic
system configuration contributed to their failure to detect their
hydraulic system configuration error.
- The pilots failed to perform the landing checklist and to
detect the numerous cues alerting them to the status of the landing
gear because of their focus on coping with the flap extension
problem and the high level of workload as a result of the rapid
sequence of events in the final minute of the flight.
- Had the landing checklist been properly performed, the flightcrew
would have detected the failure the landing gear to extend.
- Although the first officer was unwilling to overtly challenge
the captain's decision to continue the approach, he did attempt
to communicate his concern about the excessive speed of the approach
to the captain.
- There was no compelling reason for the captain's decision
to land the airplane; multiple signals and guidance indicated
that the approach should be discontinued, as did Continental Airlines'
standard operating procedures.
- The flightcrew's degraded performance is consistent with the
effects of fatigue, but there is insufficient information to determine
the extent to which it contributed to the accident.
- There were deficiencies in Continental Airlines' (COA) oversight
of its pilots and the principal operations inspector's oversight
of COA. COA was aware of inconsistencies in flightcrew adherence
to standard operating procedures within the airline; however,
corrective actions taken before the accident had not resolved
this problem.
- This accident demonstrates the need for all air carriers to
bring their checklists that apply to all phases of ground and
flight operations into compliance with the contemporary human
factors principles of checklist design outlined in the FAA's report,
"Human Performance Considerations in the Use and Design of
Aircraft Checklists."
- The "C" flight attendant was unable to completely
remove the tailcone access plug door, because one of the aft jumpseat
shoulder harness straps was buckled to the lap belt, which tied
the plug door to the cabin bulkhead. Fortunately, the lack of
availability of the tailcone exit did not preclude a timely and
successful evacuation.
- Continental Airlines flight attendants received inadequate
information and training on the operation of the DC-9 tailcone
access plug door.
Probable Cause
The National Transportation Safety Board determines that the probable
cause of this accident was the captain's decision to continue
the approach contrary to Continental Airlines (COA) standard operating
procedures that mandate a co-around when an approach is unstabilized
below 500 feet or a ground proximity warning system alert continues
below 200 feet above field elevation. The following factors contributed
to the accident: (1) the flightcrew's failure to properly complete
the in-range checklist, which resulted in a lack of hydraulic
pressure to lower the landing gear and deploy the flaps; (2) the
flightcrew's failure to perform the landing gear checklist and
confirm the landing gear was extended; (3) the inadequate remedial
actions by COA to ensure adherence to standard operating procedures;
(4) the Federal Aviation Administration's inadequate oversight
of COA to ensure adherence to standard operating procedures.
RECOMMENDATIONS
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 DC-9 and MD-80 operators with the "HI, LOW, OFF"
hydraulic switch configuration to revise their checklists to emphasize
the importance of the "Hydraulics" item by placing it
as the first item on the in-range checklist (or equivalent), and
requiring that both pilots verbally verify hydraulic pump switch
settings and system pressures. (A-97-3)
Require all principal operations inspectors of 14 CFR Part 121
operators using DC-9 and MD-80 airplanes with the "HI, LOW,
OFF" hydraulic switch configuration to ensure that operating
manuals and training programs include information about the consequences
of improper hydraulic system configuration, specifically that
the flaps and landing gear will not function normally if the engine-driven
hydraulic pumps are not set to "HI." (A-97-4)
Require all principal operations inspectors of 14 CFR Part 121
carriers to ensure that the carriers establish a policy and make
it clear to their pilots that there will be no negative repercussions
for appropriate questioning in accordance with crew resource management
techniques of another pilot's decision or action. (A-97-5)
Require all principal operations inspectors of 14 CFR Part 121
carriers to ensure that crew resource management programs provide
pilots with training in recognizing the need for, and practice
in presenting, clear and unambiguous communications of flight-related
concerns. (A-97-6)
Require Continental Airlines to audit its internal oversight process
and correct deficiencies in that oversight process that allow
deviations from standard operating procedures and violations of
Federal regulations to go uncorrected, and to develop a specific
plan to reinforce the importance of adherence to standard operating
procedures among pilots. (A-97-7)
Audit its surveillance of Continental Airlines (COA) en route
operations to determine if the surveillance is adequate to identify
procedural deficiencies in COA s operations. (A-97-8)
Require that principal operations inspectors review the checklists
of air carriers operating under 14 CFR Parts 121 and 135 to ensure
that they comply with the guidance presented in the Federal Aviation
Administration report entitled "Human Performance Considerations
in the Use and Design of Aircraft Checklists," and require
that any checklists that do not comply with the guidance be revised
according (A-97-9)
Amend Flight Standards Handbook Bulletin 96-02, "Guidelines
for Crewmember Training on Aircraft Tailcones and Approval of
Tailcone Training Devices," to include a requirement that
if any portion of a restraint system is attached to the tailcone
access plug door in the aircraft that might interfere with the
opening of the door, the plug door training device must be equipped
with the entire restraint system. (A-97-10)
BY THE NATIONAL TRANSPORTATION SAFETY BOARD
JAMES E. HALL
Chairman
ROBERT T. FRANCIS II
Vice Chairman
JOHN A. HAMMERSCHMIDT
Member
JOHN J. GOGLIA
Member
GEORGE W. BLACK
Member
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