Thursday, January 07, 2010

Jamaica Civil Aviation Authority preliminary report on American Airlines Flight 331 accident in Kingston

by B. N. Sullivan

Jamaica Civil Aviation AuthorityThe Jamaica Civil Aviation Authority (JCAA) has released preliminary information regarding the investigation into the American Airlines Flight 331 accident at Kingston, Jamaica. The aircraft, a Boeing 737-800 (registration N977AN), overran the runway at Kingston's Norman Manley International Airport (MKJP) late on the evening of Tuesday, December 22, 2009 as it was arriving from Miami. There were no fatalities among the six crew members and 148 passengers on board, although there were some injuries.

The brief factual report (link below) notes that instrument meteorological conditions prevailed in the area and heavy rain was reported at the airport at the time of the accident. The aircraft was flying on an Instrument Flight Rules Flight Plan.

Quoting from the report:
According to the Norman Manley Tower Controller, as the aircraft was approaching Jamaica the Automatic Terminal Information Service (ATIS) for MKJP, which relays recorded airport and weather information, was broadcasting Runway 12 as the runway designated for arrivals.

The crew contacted Jamaican Air Traffic Control and requested the Instrument Landing System (ILS) approach for Runway 12. The controller advised the crew of tailwind conditions on Runway 12 and offered them a circling approach for landing on Runway 30. The crew repeated their request for Runway 12 and were subsequently cleared to land on that runway, with the controller further advising the crew that the runway was wet. The Captain, who was the pilot flying, reported that he used the Heads Up Display (HUD) during the approach and landing.

The crew reported that after descending through the cloud cover, they made visual contact with the runway at between 1000 feet and 700 feet above ground level. According to the Flight Data Recorder (FDR), the aircraft was traveling at the Vref (landing) airspeed of 148 knots, with a groundspeed of 162 knots, i.e. with a tailwind component of 14 knots, when the wheels made initial contact at about 4,000 feet down the 8,900-foot runway. The FDR further indicated that the aircraft bounced once, then settled onto the runway; the autobrakes then engaged, and reverse thrust and the spoilers were deployed.

The crew reported that at that point they felt that the aircraft did not decelerate normally, and they subsequently applied maximum manual (pedal) braking. The FDR indicates that the aircraft decelerated normally for an autobrake 3 setting.

The FDR indicates that during the landing rollout the aircraft veered to the left of centerline and departed the end of the runway at a groundspeed of 63 knots. Examination of the crash site indicates that the aircraft then exited the runway, went through the perimeter fence, crossed a road, and came to rest on a rock-strewn beach about 175 feet beyond the departure end of Runway 12 and about 40 feet from the water line.
The report goes on to describe the wreckage, stating that the aircraft's fuselage was broken into three major pieces; the right engine, right inboard aft trailing edge flap and the right main landing gear separated from the aircraft; and the left winglet "was almost broken off the wing."

Preliminary examination of the Flight Data Recorder (FDR) contents revealed no "anomalies or malfunctions with the operation of the brakes, spoilers or thrust reversers." The rate of deceleration "appears normal for a wet runway." In short, "no mechanical problems have been found with any aspect of the aircraft."

Grand Cayman was the designated alternate airport for the flight, and the aircraft "had sufficient fuel on board to reach that destination." Also noted: The aircraft was below the maximum permitted landing weight.

Investigators are evaluating runway surface conditions at the time of landing "to determine the effect of this on the braking forces."

The report also mentions that "ground-based navigation and landing aids were evaluated by a check aircraft after the accident, and were determined to be functioning normally."

The wreckage of the accident aircraft will be shipped to the U.S. where it will be held in a secure location while the investigation continues.

Link to the JCAA report: American Airlines Flight 331 Accident Update, Jan. 5, 2010 - 4-page 'pdf' file