Final Report: Slushy runway factor in overrun

 - February 8, 2007, 5:11 AM

DASSAULT FALCON 20, PUEBLO, COLO., JAN. 21, 2004. The captain of the Jet Ex Falcon 20 said he had no indication of runway problems from notams or from a low pass over Runway 8L at the Pueblo Memorial Airport. He landed and the airplane initially decelerated with normal braking.

When the airplane encountered snow and ice patches, the pilot deployed the thrust reversers. The airplane began to yaw to the left and differential braking failed to straighten the airplane. The captain said the airplane ran off the left side of the runway and rotated counterclockwise before coming to rest. A witness said, “I heard the [thrust] reversers go on and then off, and then on again. As they came back on for the second time, that’s when the airplane started making full circles on the runway. This happened two, maybe three times before [it went] off the side of the runway.”

The airplane’s right main landing gear collapsed on leaving the runway, causing substantial damage to the right wing, right main landing gear and aft pressure bulkhead. There were no injuries. The right engine thrust reverser was found partially deployed, while the left was fully deployed with the blocker doors extended. An examination revealed a stuck solenoid on the right engine thrust reverser.

Approximately 33 minutes before the accident, the pilot requested weather for the airport. Denver Center included in the conditions “at least a half inch of slush on all surfaces.” The pilot acknowledged the information. The airport notam stated there was “one-half inch wet snow all surfaces.”

The NTSB determined the probable cause was the pilot’s improper in-flight planning/decision to land on the contaminated runway; the stuck thrust reverser solenoid, resulting in partial deployment of the right engine thrust reverser; and the pilot’s inability to maintain directional control of the airplane due to the asymmetric thrust combined with a contaminated runway. Factors contributing to the accident were the wet, snow-covered runway, the airport’s failure to remove the snow from the runway and the pilot’s failure to recognize the hazardous runway conditions reported by air traffic control.