Accident Overview
On June 20, 2008, at 1020 eastern daylight time, a Cirrus SR-20, registration N381CP, experienced a wheel brake fire at Williston Municipal Airport (X60), Williston, Florida. The aircraft was operating on a solo instructional cross-country flight under Title 14 Code of Federal Regulations Part 91, conducted by Commercial Airline Pilot Training, LLC. Visual meteorological conditions prevailed, and a visual flight rules flight plan had been filed. The student pilot reported no injuries, and the airplane sustained substantial damage.
Landing and Takeoff Sequence
The student pilot, who had accumulated 82 hours in the Cirrus SR-20, had departed from Flagler County Airport in Palm Coast, Florida. Upon arriving at X60, he completed two full-stop landings and then taxied back to the runway intending to perform three additional landings. The pilot aborted the initial takeoff attempt and taxied back to the runway for a second attempt. During the second takeoff roll, he aborted again. When attempting to stop, he noticed that the brakes were not functioning properly. As he exited the runway, smoke was observed coming from under the wings. He quickly secured the fuel and avionics, grabbed the onboard fire extinguisher, and exited the airplane. Despite efforts by the pilot, the airport supervisor, and the fire department, the right main landing gear was completely destroyed by the fire. The fire burned through the bottom of the fuselage, extended up the right side of the cabin behind the wing, and caused thermal damage to the lower surface of the right wing. The left main landing gear also sustained thermal damage on top of the wheel pant assembly.
Examination Findings
The left main landing gear assembly and the remaining components from the right main landing gear assembly were sent to the Parker Hannifin Wheel and Brake Division in Avon, Ohio, for a teardown examination with Federal Aviation Administration oversight. The examination revealed that the O-rings from the left-hand brake cylinder had deformed and taken on a square appearance. A subsequent functional inspection demonstrated that the brake assembly held pressure in accordance with established production parameters. The right-hand landing gear assembly was destroyed by the magnesium fire, and the remnants could not be tested.
Avionics Data
The aircraft was equipped with an Avidyne avionics system, including a primary flight display (PFD) and a multi-function display (MFD), each capable of storing data. The data from the PFD and MFD were extracted and analyzed by the National Transportation Safety Board's Vehicle Recorder Division. Analysis indicated that within a time frame of 22 minutes, the pilot executed two landings at X60 followed by two aborted takeoffs. Ground taxi speeds between events ranged from 35 knots to 73 knots, while engine speed during taxi ranged from 920 RPM to 1270 RPM.
According to the Cirrus SR-20 Pilot Operating Handbook (POH), the maximum continuous engine speed for taxiing is 1000 RPM. The POH noted that if engine speed is exceeded and proper braking procedures are not observed, wheel brake damage or fire could occur. At the time of the accident, there were no references to high-speed aborted takeoff limitations in the POH.