McDonnell Douglas MD-11 accident at Newark, New Jersey, 31 Jul 1997

Accident narrative

On July 31, 1997, about 0132 eastern daylight time, a McDonnell Douglas MD-11 operated by Federal Express, Inc. (FedEx) as flight 14 crashed while landing on runway 22R at Newark International Airport in Newark, New Jersey. After an initial touchdown, the airplane bounced, touched down a second time on its right main landing gear, and sustained a structural failure of the right wing. The airplane rolled inverted, slid off the runway, and was destroyed by impact and a postcrash fire. All five occupants received minor injuries.

### The flight

Flight 14 was a regularly scheduled cargo flight that originated in Singapore on July 30, with intermediate stops in Penang, Malaysia; Taipei, Taiwan; and Anchorage, Alaska. The final leg from Anchorage to Newark was conducted on an instrument flight rules flight plan. On board were the captain, the first officer, one jumpseat passenger, and two cabin passengers.

The captain, 46, had logged 11,000 total flying hours, including 1,253 hours in the MD-11, with 318 hours as pilot-in-command. The first officer, 39, had 3,703 total flying hours, including 95 hours in the MD-11.

The airplane was dispatched from Anchorage with the No. 1 (left engine) thrust reverser inoperative, which was approved under the minimum equipment list. The flight to the Newark area was routine.

During the descent, the flight crew discussed the approach and the airplane's landing performance. Using the airport performance laptop computer (APLC), the first officer determined that the stopping distance would be approximately 6,080 feet using medium autobrakes. The crew compared this to the 6,860-foot after-glideslope touchdown distance provided on the approach plate, calculating a 780-foot margin. They then compared the maximum autobrake stopping distance of 5,030 feet to the same 6,860-foot figure, calculating a 1,830-foot margin. Based on these calculations, the first officer suggested using maximum autobrakes. The captain agreed, stating they had "a lot of stuff going against us here." The Board noted that the crew misinterpreted the data; the stopping distance should have been compared to the total APLC runway distance of 7,760 feet, which would have provided a 1,680-foot margin for medium brakes.

During the approach, the captain also noted that the left landing light was inoperative. He asked the first officer to remind him to use only the No. 2 and No. 3 thrust reversers during the landing.

### The sequence of events

The Newark tower controller cleared flight 14 to land at 0129:45, advising of winds from 250 degrees at 5 knots. The captain disengaged the autopilot at an altitude of 1,200 feet and hand-flew the airplane, leaving the autothrottles engaged. The approach was stabilized on the glideslope and localizer, with an airspeed of about 158 knots.

Flight data recorder (FDR) information indicated that the captain initiated the landing flare at 38 feet radio altitude. Pitch attitude increased to 4.9 degrees, and engine thrust decreased. As the airplane descended through 17 feet, the captain initiated an airplane nose-down elevator deflection. The pitch attitude and vertical acceleration began to decrease.

At 0132:17.6, as the airplane descended through 7 feet, the FDR recorded an airplane nose-up elevator deflection of up to 26 degrees, a nose-left rudder deflection, a right-wing-down aileron deflection, and a throttle increase to 74 degrees.

The airplane touched down at 0132:18.6, 1,126 feet beyond the displaced threshold, with a 7-degree nose-up pitch attitude and a vertical speed of about 7.6 feet per second. Vertical acceleration peaked at 1.67 g. About one-half second later, the FDR recorded an 18-degree nose-down elevator deflection and a throttle decrease. Ground spoilers did not deploy because the throttle lever angle was greater than 49 degrees.

Following the initial touchdown, the airplane became airborne again. As its altitude increased, it pitched nose-down and rolled right-wing-down. The airplane reached an altitude of about 5 feet above ground level and began to descend. As it descended, the FDR recorded about 23 degrees of nose-up elevator, 12 degrees of nose-left rudder, and additional right-wing-down aileron deflections.

The airplane touched down a second time at 0132:21.6, about 1,889 feet from the displaced threshold. It impacted with a 9.5-degree right-wing-down roll angle, a 7-degree-per-second right roll rate, and a 0.70-degree nose-down pitch attitude. The peak vertical speed at the right main landing gear was about 13.5 feet per second.

The right wing failed upon impact. The airplane rolled to the right, inverted, and slid down the runway, coming to rest 5,126 feet beyond the threshold and 580 feet to the right of the runway centerline. A fuel-fed fire erupted. The occupants evacuated through a cockpit window.

### What the investigation found

The Board found no evidence of preexisting structural damage or degradation to the airplane, systems, or components. The right main landing gear separated from its attach points in an overload failure, with no evidence of fatigue cracking or corrosion. Electronic flight control systems operated normally before the accident.

The investigation determined that the airplane's approach before the landing flare was stabilized, and the captain's initial flare maneuver was normal. However, the Board found that the captain's nose-down elevator input at 17 feet was not consistent with FedEx guidance. The Board concluded this input was consistent with an attempt to control the point of touchdown due to the captain's concerns about runway length. The crew's earlier miscalculation of the APLC data had created a sense of urgency to touch down early.

The nose-down input at 17 feet increased the sink rate. The Board concluded that the captain then made a nearly full nose-up elevator input and a large throttle increase to compensate. At the time of the first touchdown, the captain made a full nose-down elevator input, which the Board found consistent with his desire to avoid a long landing and a tailstrike. This sequence of rapid, opposing elevator inputs constituted a pilot-induced oscillation.

The Board concluded that the accident airplane performed normally in response to the captain's flight control inputs until after the second touchdown. The energy transmitted into the right main landing gear during the second touchdown was 3.2 times greater than the MD-11's maximum certificated landing energy. This energy was sufficient to fully compress the right main landing gear strut and cause the structural failure of the right wing rear spar, which ruptured the fuel tanks and caused the fire.

The Board evaluated other factors and ruled them out as causes. The inoperative left landing light did not impede the captain's ability to land. The MD-11's known tendency to pitch up at ground spoiler deployment did not contribute to the accident, nor did the throttle-driven ground spoiler knockdown feature.

The Board concluded that air carrier pilots' performance would be improved by additional guidance and training in landing techniques. The Board also concluded that handling changes incorporated in a newly developed flight control computer software upgrade (FCC-908) would provide valuable safety improvements during MD-11 landings by decreasing pitch sensitivity.

The investigation also noted issues with the dissemination of hazardous materials information. Emergency responders did not receive a complete list of the specific hazardous materials on board until more than four and a half hours after the initial request. However, the incident commander had assumed hazardous materials were present and took appropriate precautions, which the Board concluded minimized risks to responders and the community.

### Probable cause

The National Transportation Safety Board determined that the probable cause of this accident was the captain’s overcontrol of the airplane during the landing and his failure to execute a go-around from a destabilized flare. Contributing to the accident was the captain’s concern with touching down early to ensure adequate stopping distance.