An American Airlines 757-200 that ran off the departure end of a snowy Runway 19 at Jackson Hole Airport on Dec. 29, 2010, actually had a chance of stopping, the NTSB announced Tuesday. None of the 185 aboard Flight 2253 were injured, but the aircraft suffered minor damage and passengers were rattled. (AVweb video.) The NTSB found that the Boeing, flown by the co-pilot, touched down normally about 600 feet beyond the runway threshold. The speedbrakes failed to automatically deploy and when the first officer attempted to deploy the thrust reversers, they did not respond properly. The NTSB found mechanical causes for each mechanical failure. It also noted that the jet could have stopped on the runway even without the reversers if the pilots had reacted differently.
According to the NTSB, the captain, acting as the monitoring pilot, “failed to identify the non-deployment” of the speedbrakes upon landing and instead stated “deployed” shortly after touchdown. Then, when the thrust reversers failed to deploy, the captain joined the first officer in concentrating on that problem. Because of that, said the NTSB, “neither pilot recognized that the speedbrakes had not automatically deployed.” The investigation found that had the captain acted promptly to manually deploy the speedbrakes after landing, the jet could have stopped on the runway with 1900 feet remaining. The Board found that a “latent assembly defect” caused the problem with the speedbrakes. As for the reversers, the investigation determined that that failure was caused by “a rare mechanical/hydraulic interaction” that occurred “as a result of an unloading event at the precise instant that the first officer commanded their deployment.”The NTSB has made safety recommendations to the FAA regarding pilot training and aircraft manufacture relevant to this event.
