What happened
During a repositioning flight from Jeddah to Riyadh, the crew of a Saudi Arabian Airlines MD-90 decided to perform a landing using manual spoilers instead of the automated system. The captain, noting his limited experience with this specific aircraft type, intended to test the effects of manual spoiler deployment under ideal weather and dry runway conditions. Following the completion of the landing checklist, the captain intentionally disarmed the auto ground spoiler system and did not arm the auto braking system.
Upon touchdown on runway 15 Left at a speed of 135 knots, the captain manually moved the speed brake lever but failed to latch it in the fully extended position. After releasing the lever to operate the thrust reversers, the lever automatically returned to the retracted position. This caused the ground spoilers to stow before they were fully deployed, triggering a configuration alert.
As the aircraft continued along the runway, it began to drift toward the right side of the centerline. The crew attempted to correct the drift using left rudder and aileron inputs, but these actions were ineffective. In an effort to avoid overshooting the G4 taxiway exit, the captain applied right rudder, which initiated a sharp turn. The aircraft exited the runway at high speed, crossed the G4 taxiway, and entered a sandy area. During the excursion, the left main landing gear collapsed, and the MD-90 eventually came to a stop on taxiway GOLF. There were no fatalities among the seven crew members, and no post-impact fire occurred.
Findings
- The crew intentionally operated the aircraft with the auto ground spoiler and auto braking systems disarmed to test manual deployment.
- The failure to latch the speed brake lever in the fully extended position caused the spoilers to retract prematurely during the landing roll.