Incident
The aircraft, registered as N508US and operating as Northwest Airlines Flight 150, experienced an abrupt pitch-up during landing. According to the captain, the flight had been uneventful until the landing phase. Upon touchdown and deployment of the spoilers, the aircraft pitched up suddenly to an attitude of 10 degrees. The landing was completed without further incident.
Aircraft Examination
Post-landing inspection of the aircraft revealed damage to the underside of the fuselage belly. No other details regarding the extent or specific location of the damage were provided.
Boeing Service Bulletin
Boeing issued a service bulletin in response to the incident. The bulletin stated that spoiler deployment on touchdown would produce a nose-up aerodynamic moment. To address this, the bulletin recommended two solutions: a modification to the spoiler deployment sequence and the use of autobraking during landing.