Final Report: Pilot pushed spoileron circuit breaker

 - February 27, 2009, 10:33 AM

Bombardier Learjet 35A, Goodland, Kan., Oct. 17, 2007–The pilot’s failure to maintain control of the Learjet was the cause of its running off the runway on landing at Renner Field, according to the NTSB. The jet had broken out of the clouds at 250 feet agl, and when the pilot tried to align the airplane with the centerline, he experienced an uncontrolled left and right rolling motion and noticed that the aileron augment (spoileron) annunciator light was on. The right tip tank hit the runway and the aircraft ran off the right side of the runway; the aircraft then banked left and the left tip tank hit the runway. Neither pilot was injured.

Maintenance records revealed that the aircraft’s spoileron system was not “working properly” and maintenance was done on October 2. The customer recalled the airplane while the spoileron system was being troubleshot and the system had been “deactivated” in accordance with the Learjet minimum equipment list procedure. The circuit breaker was pulled and secured with a tie wrap and a decal
was installed on the instrument panel indicating the system was deactivated. Investigators found neither the tie wrap nor decal after the accident and both the spoiler and spoileron circuit breakers were in the closed position.

According to the pilot, the “aug/ail” circuit breaker had been pulled during the entire flight except for a short time in cruise when he attempted to reset the system. The system would not reset so he pulled the circuit breaker and it remained in that position for the rest of the flight.