A McDonnell Douglas MD90 was operating a positioning flight from Jeddah to Riyadh (Saudi Arabia). Onboard a crew of 7 for an uneventful (~850 km / 530 miles) flight. During the flight, the captain discussed the use of manual spoilers instead of auto spoilers with the first officer.
As the captain had only landed the MD90 with the use of auto spoilers, he saw this positioning flight as the ideal opportunity to land the aircraft and use the manual spoiler function and "see the effect".
The aircraft after coming to a stop (Source www.avherald.com © Unknown)
During the approach to Riyadh, the Landing Checklist was performed which included the arming of the auto ground spoiler system for landing. After the Landing Checklist was completed the auto ground spoiler system was disarmed in anticipation of the use of manual spoilers on landing. The auto brake system remained off during the flight. The final approach and touchdown on runway 15L at Riyadh were uneventful. The touchdown speed was 135 knots. As briefed the captain manually extended the spoiler/speed brake lever, but did not latch it in the full extend and latch position. The captain then removed his hand to the reverser levers to deploy the reverser. When the co-pilot saw the lever move, he called "Spoilers Deployed". What the crew didn't notice was that the spoiler/speed brake lever retracted (as per design) to the stowed position. And with that the spoilers retracted. For six seconds a "SPD BRK/FLP CONFIG" level1 amber alert was presented as the aircraft was not fully Weight On Wheels, while the Flaps were extended more then 6º and the spoilers (at that time) were not retracted (In flight, flaps in landing configuration wit spoilers not stowed).
The aircraft resting on its left wing (source; www.baaa-acro.com © Unknown)
After touchdownthe aircraft banked right and drifted to th right of the centerline, corrective action was taken but did not have an effect. With an runway exit approaching the captain riappliedght rudder to steer the aircraft on to th exit and off the runway. This caused a sharp turn towards the runway exit, the aircraft left the runway at high speed, crossed the exit and taxiway and left the paved surface. the left main landing gear collapsed and the aircraft came to a halt on a taxiway. There was no post impact fire, and all the crew evacuated the aircraft without injury.
Sources on the internet give the following cause relate findings for this landing accident;
Decision to use manual spilers while the auto function was operational
Actions contravened the airlines Standard Operating Procedures (SOPs) and the Flight Operations Policy Manual (FOPM).
The spoiler/speed brake lever had not been moved completely to the extend position and was released prematurely
The spoiler/speed brake lever retraction swasper design
Lack of spoilers resulted in less deceleration and less loss of lift
Brakes were not used
Large rudder input toward the runway exit
Aircraft was traveling to fast to safely use the exit
The aircraft shortly after the landing (source; Youtube.com © hejaztube)
V2 Aviation Training & Maintenance wrote this blog using open source data. We have been unable to find an official report relating to this incident. If inconsistencies are noticed in this blog don't hesitate tp contact V2 Aviation via the comments section at the bottom of this page, or via the contact page of this website.