NTSB Factual Report

On January 24, 2011, at 1100 eastern standard time, a Cirrus SR-22, N690KY, registered to Functional Pathways Preferred of Tennessee LLC, and operated by an airline transport pilot had a brake and wheel fire during taxi at the Pittsburgh International Airport (PIT), Pittsburgh, Pennsylvania. The personal flight was operated under the provisions of 14 Code of Federal Regulations Part 91 and an instrument flight rule (IFR) flight plan was filed. Visual meteorological conditions prevailed. The airline transport pilot and passenger were not injured, and the airplane received substantial damage. The flight was originating at the time of the accident.

According to the pilot, after conducting a preflight inspection he obtained his IFR clearance. He was given taxi instructions to taxi from the fixed base operator to runway 10R. During the taxi the pilot stated that he did not have any indication of trouble from the brakes, and normal braking pressures were used to control the aircraft. Upon reaching runway 10R, the takeoff checklist was started. The pilot increased the engine rpm as per the checklist and the airplane moved forward slightly. As pressure was applied to the brakes, the right brake "popped" and the right pedal lost all pressure. The airplane started a 180° turn to the left and the engine was shutdown. Smoke was coming from under the right wing and the tower was alerted. As the pilot and passenger exited the airplane they observed that the smoke was coming from the right wheel pant. Flames began to show around the base of the wheel pant and the pilot attempted to extinguish the fire unsuccessfully. The airport fire fighting crew arrived and extinguished the fire.

According to a Federal Aviation Administration inspector who subsequently examined the airplane, the right wheel assembly was heavily fire damaged and broken away from the strut. The strut coating was burnt to the fibers, and the underside of the wing was heavily blistered. Further examination revealed that the remaining wheel assembly components were destroyed by fire. Examination of the left brake assembly did not revealed any evidence of mechanical failure.

The airplane was equipped with an Avidyne avionics system which consisted of a multi-function display (MFD). The data from the MFD was extracted and analyzed by the National Transportation Safety Board's Vehicle Recorder Division. The data indicated that the pilot reached ground speeds of 30 knots and engine power during taxi ranged from 1,100 to 1,900 rpm. Review of the airplane's pilot operating handbook revealed that the maximum recommended continuous engine power for taxiing is 1,000 rpm. If the engine power is exceeded and proper braking procedures are not observed during taxi, wheel brake damage or fire could occur.

NTSB Probable Cause

The pilot’s excessive engine rpm and speed during taxi and subsequent braking, which resulted in a wheel brake fire.