Incident Overview
On September 11, 2019, at 1315 mountain daylight time, a Piper PA-28-181 airplane, registration N8384E, experienced a left main landing gear fire during landing rollout at City of Colorado Springs Municipal Airport (COS), Colorado Springs, Colorado. The commercial pilot and a passenger were uninjured. The airplane's left wing sustained substantial damage. The aircraft was registered to G & M Aircraft Inc, used as a rental by Rocky Mountain Flight School, and operated under Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed. The flight originated from Tradewind Airport (TDW), Amarillo, Texas, at 1131 central daylight time.
Pilot Report
The pilot stated that after landing on runway 35R, he taxied off at E5. Air traffic control (ATC) cleared him to taxi to general aviation via taxiways E and H and to cross runway 35L. Unfamiliar with the airport, he taxied north on taxiway E. ATC asked him to pick up the pace if able; he responded that he could make room ahead if needed. As the airplane exited taxiway E onto H near taxiway P, he noticed the brakes were no longer available. He tried the emergency (parking) brake, but it was unresponsive. He planned zig-zags to slow down and make turns. During two shallow zig-zags, he heard a loud bang and the airplane veered left. Stomping on the rudder had little effect. Shortly after, the passenger yelled "fire." Upon exiting, the pilot saw the left main landing gear was on fire. He attributed the event to a mechanical malfunction/failure of the brakes.
According to the Federal Aviation Administration (FAA) inspector, the pilot initially stated that he probably rode the brakes longer than he should have, but later stated it was a normal landing and he hardly touched the brakes. After the factual report was issued, the pilot denied making that statement, calling it "incorrect."
Brake System Description
The airplane brake system consisted of toe brakes on each rudder pedal with brake cylinders. The left toe brake master cylinder independently controlled the left main landing gear wheel brake, and the right toe brake master cylinder independently controlled the right main landing gear wheel brake. The parking brake cylinder simultaneously controlled both main landing gear wheel brakes.
Post-Accident Examination
Post-accident examinations by an FAA inspector and the National Transportation Safety Board (NTSB) Investigator-in-Charge (IIC) revealed fire damage from the left main landing gear wheel brake assembly extending to the left wing structure, and thermal damage from the right main wheel brake assembly. Examination of the brake system components showed no mechanical anomalies that would have precluded normal operation. All rudder pedal brake cylinders and the parking brake cylinder were attached and secure. When exercised by hand pressure, there was no binding in movement of the actuator springs, and all springs returned to their uncompressed positions. The FAA's Airplane Flying Handbook (FAA-H-8083-3B) notes that safe taxiing requires positive control and avoidance of undue reliance on brakes, but no specific link to this accident was established.