National Transportation Safety Board
Office of Public Affairs
Washington, DC - A combination of pilot mistakes during a special aircraft maneuver, coupled with inadequate flightcrew training and procedures by Airborne Express, led to a fatal accident when one of the company's newly retrofitted DC-8 cargo planes crashed into mountains, the National Transportation Safety Board (NTSB) has determined.
The accident occurred on December 22, 1996, at 6:10 p.m. in the vicinity of Narrows, Virginia, while a team of pilots and technicians were conducting a post-modification functional evaluation flight to check out the aircraft, which had received a major overhaul and upgrades. The functional evaluation flight originated from Piedmont Triad International Airport, Greensboro, North Carolina.
The three flightcrew members and three maintenance-avionics technicians on board were killed. The airplane was destroyed by the impact and a postcrash fire.
At a public meeting, the NTSB determined that the probable causes of the accident were inappropriate control inputs by the flying pilot during a stall recovery attempt; the failure of the non-flying pilot-in-command to recognize, address and correct these inappropriate control inputs; and the failure of Airborne Express to establish a formal, functional evaluation flight program that included adequate program guidelines, requirements and pilot training for performance of these flights.
Contributing to the cause of the accident, the NTSB said, were an inoperative stick shaker stall warning system and the DC-8 flight training simulator's inadequate fidelity in reproducing the airplane's stall characteristics.
This accident might have been prevented, the NTSB said, if the flightcrew had been provided a clear, direct indication of the airplane's angle of attack. The Safety Board also said the accident could have been prevented if Airborne Express had institutionalized -- and the flightcrew had used -- a revised evaluation flight stall recovery procedure agreed upon by Airborne Express and the FAA in 1991 after a similar, but non-fatal incident.
Among its accident conclusions, the NTSB said Airborne Express should have required completion of a functional evaluation flight by sundown or should have established adequate night and weather limitations. Because of delays earlier in the day, the flightcrew conducted these maneuvers when it was dark without a visible natural horizon, depriving them of an important flight attitude reference that would have aided in their recovery from a full stall.
As a result of the accident investigation, the NTSB issued a series of recommendations to the Federal Aviation Administration urging it to:
Ensure that Airborne Express explicitly incorporates the 1991 revised functional evaluation flight stall recovery procedure, or an equivalent procedure, in its DC-8 functional evaluation flight program.
Require Douglas Aircraft Company to review and amend the stall warning test procedures in the DC-8 maintenance manual to include regular calibration and functional checks of the complete stall warning system.
Evaluate available data on stall characteristics of airplanes used in air carrier service and, if appropriate, require the manufacturers and operators of flight simulators to improve them by reproducing airplane stall characteristics to the maximum extent that is practical; then add training in recovery from stalls with pitch attitudes at or below the horizon to the special events training programs.
Provide guidance to air carriers on the appropriate conditions, limitations and tolerances for the performance of functional evaluation flights and the specific maneuvers performed during these flights, including approach to stalls.
Add specific operational guidance, flightcrew training and qualification requirements to federal aviation regulations on training programs for non-routine operations including functional evaluation flights.
Undertake an appropriate level of surveillance of the functional evaluation flight programs of all air carriers, following implementation of NTSB's suggested changes to functional evaluation flight and other non-routine operations.
Modify the operating and airworthiness regulations or issue appropriate guidance material to clarify airworthiness and operational procedural requirements for conducting functional evaluation flights in transport category aircraft.
In addition, the NTSB reiterated a safety recommendation it made in 1996 following the crash of an American Airlines 757 near Cali, Colombia. It again urged the FAA to require that all transport-category aircraft give pilots angle of attack information in a visual format, and train pilots to use the information to obtain maximum possible climb performance.
The NTSB's complete report, PB97-910405, may be purchased from the National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22162, (703) 487-4650.
Media contact: Pat Cariseo
This press release and other NTSB information are available on the World wide Web: http://www.ntsb.gov
The National Transportation Safety Board (NTSB) is an independent federal agency charged with determining the probable cause
of transportation accidents, promoting transportation safety, and assisting victims of transportation accidents and their families.