NTSB Identification: DCA09FA047
Scheduled 14 CFR Part 121: Air Carrier Northwest Airlines
Accident occurred Monday, May 04, 2009 in Denver, CO
Probable Cause Approval Date: 04/22/2010
Aircraft: AIRBUS A320, registration: N311US
Injuries: 4 Minor,150 Uninjured.
NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The flight crew was conducting a straight-in approach during visual meteorological conditions. The approach was backed up by an instrument landing system and was stable at 1000 feet above touchdown. During the final approach the crew noted an increasing tailwind. As the first officer (FO) entered the flare, the “retard” automatic callout sounded; this automatic call-out is designed to remind the pilot to move the thrust levers to idle. Despite the callout, the thrust levers remained at climb and the autothrust system commanded increased engine power in an attempt to recover airspeed. The airplane touched down, but then bounced as a result of excess thrust and the position of the thrust levers forward of idle, which prevented deployment of the spoilers. The FO then retarded the thrust levers, which allowed spoiler deployment, and the airplane touched down firmly. During the second touchdown, the FO began pitching the airplane nose up to about 12.5 degrees, which is greater than the specified maximum pitch angle and which resulted in the tailstrike. The captain attempted to add nose-down pitch to prevent the tailstrike but was too late. The aircraft experienced heavy abrasions, dents, and perforations of the skin; the aft galley drain mast and two aircraft antennas were broken; the auxiliary power unit air intake sustained damage and the rear pressure bulkhead was buckled and cracked.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The first officer’s excessive pitch-up of the airplane while landing with a tailwind, which resulted in a tailstrike following a bounced landing. Contributing to the bounced landing were a high descent rate and excessive thrust resulting from the first officer’s delay in retarding the thrust levers to idle, thereby providing residual thrust and preventing spoiler deployment. Full narrative available
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