McDonnell Douglas DC-10-30 accident at Fort Worth International Airport, Texas, 14 Apr 1993

Accident narrative

On April 14, 1993, about 0659 central daylight time, American Airlines flight 102, a McDonnell Douglas DC-10-30, departed the right side of runway 17 left after landing at Dallas/Fort Worth International Airport, Texas. The flight was a nonstop, overnight trip from Honolulu International Airport, Hawaii. It was raining at the time of the landing, and there were numerous thunderstorms in the area. Of the 202 persons aboard, two passengers received serious injuries during the evacuation, and 35 passengers, one flightcrew member, and two cabincrew members received minor injuries. The airplane sustained substantial damage.

### The flight

The flightcrew consisted of a captain, a first officer, and a flight engineer. The captain had 12,562 flight hours, including 555 hours in the DC-10. The first officer had 4,454 flight hours, with 376 in the DC-10. The flight engineer had 20,000 flight hours, all as a flight engineer, including 4,800 in the DC-10.

Prior to departure from Honolulu, the flightcrew received a weather briefing indicating possible thunderstorms and turbulence upon arrival at Dallas/Fort Worth. During the predeparture briefing, the captain told the flight attendants that possible turbulence was expected.

### Sequence of events

About 30 minutes prior to landing, the captain announced on the public address system that the radar showed numerous areas of rain showers around the airport and that they would be deviating to pick a path through the cells.

At 0634, the captain asked the Fort Worth Center controller about the possibility of landing to the north. The controller later advised that southbound departures would preclude landing to the north. Around 14 miles from the airport, the flightcrew saw a brilliant flash of light and heard a rumble that sounded like thunder. The flight engineer found no system malfunctions. The captain described the lightning to air traffic control and again requested a landing to the north, which was denied.

At 0644, the flight engineer received the terminal arrival information, which reported a measured ceiling of 1,400 feet overcast, visibility of two and one half miles, thunderstorms, rain showers, and fog.

At 0649, approach control advised the flightcrew that radar showed weather all down the final approach course. The captain stated that it was a "pretty big red area" on their scope and that they would have to "wait around to see what's goin' on." The controller then informed them that a heavy DC-8 eight miles south of them was joining the final approach and reporting a smooth ride. The captain replied, "OK, we'll head down that way then."

The airplane was cleared for the approach. The first officer requested that the captain and flight engineer be alert for windshear, and the captain encouraged him to carry 10 to 15 knots of extra airspeed. At 0653, the cockpit microphone recorded a click, which the crew discussed as another possible lightning strike.

At 0655, the captain reported a 10- to 15-knot gain in airspeed. Approach control informed them that the DC-8 had reported airspeed fluctuations on its approach. The flight was transferred to the Dallas/Fort Worth tower and cleared to land at 0656, with the controller reporting the wind as calm.

The airplane was in a crab due to a crosswind from the right on final approach. On short final, at 0659:17, less than one second after the automated voice called out "fifty" feet, the first officer stated, "I'm gonna go around." The captain stated, "No, no, no, I got it." The first officer responded, "You got the airplane." The captain took control and landed the airplane.

The sound of touchdown was recorded at 0659:29. At 0659:36, the first officer called out 120 knots. Two seconds later, the captain uttered an expletive. At 0659:41, the first officer called out 100 knots, then stated, "OK, we're off the grass." At 0659:53, the captain ordered an emergency evacuation.

### What the investigation found

The airplane came to rest upright in the soft soil about 2,607 feet from the departure end of runway 17 left and about 250 feet from the right edge of the runway. The left main gear strut was fractured, and the nose gear strut was folded aft. A large fire developed aft of the left wing, which was extinguished soon after emergency vehicles arrived.

Tire marks on the runway showed that the airplane touched down 4,303 feet from the beginning of the runway. The tracks paralleled the runway centerline for about 1,700 feet, then turned gradually to the right until they departed the runway.

Flight data recorder information showed that the airplane touched down at 143 knots. After touchdown, the captain applied maximum reverse thrust on all three engines. About six seconds after touchdown, the airplane heading began to move to the right. The flight data recorder showed that the rudder, elevator, and ailerons moved toward the neutral position. There was basically no movement of the elevator or ailerons from the neutral position prior to the airplane departing the runway.

During postaccident interviews, the captain stated that the airplane "weathervaned" about 5 degrees to the right after touchdown. He stated that he acted "instinctively" to return to the centerline and used the nosewheel steering handwheel control, noting that he did not use asymmetric reverse power.

The Board noted that the intended use of the handwheel is to make turns at low speeds. The airplane manufacturer had published information restricting handwheel use at high speeds and emphasizing the need for forward pressure on the control column to maintain the nosewheel firmly on the ground for maximum directional control. The Board found that American Airlines did not have procedures for holding forward pressure on the yoke after touchdown, for not using the handwheel steering at high speeds, or for coming out of reverse thrust to regain directional control. American Airlines addressed regaining directional control in an "Operating Technique" section rather than as a required procedure.

Examination of the engines revealed that two of the 32 thrust reverser cascades on the center engine were the incorrect part numbers and styles. This misconfiguration altered the reverse thrust airflow, reducing the nose-down pitching moment and creating a small nose-right yawing moment. However, the Board calculated that the available flight controls were more than sufficient to offset the change due to the misconfigured cascades.

The Board found several inoperative, damaged, or out-of-tolerance valves in the flight controls, brakes, or antiskid system. The broken nosewheel steering cables were determined to be a result of overload during the crash. The Board also found no evidence of tire hydroplaning, noting that the tire marks on the runway were erasure marks on the wet surface.

Weather analysis indicated that a line of moderate to heavy rain showers and thunderstorms was crossing the runway as the airplane landed. The airplane was subjected to cross-track winds of about 15 knots. The Board found that no microbursts or hazardous low-level windshears affected the airplane.

During the evacuation, the cabin emergency lighting did not operate properly, leaving the aft cabin dark. Testing revealed that the emergency lighting battery packs had been reassembled improperly during maintenance, with individual cells out of sequence. This resulted in sufficient power to indicate a fully charged system on the flight engineer's console, but insufficient power to illuminate the lights.

### Probable cause

The National Transportation Safety Board determined that the probable cause of the accident was the failure of the captain to use proper directional control techniques to maintain the airplane on the runway.