This September 2010 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Cessna 172RG. Injuries: 1 Serious, 1 Minor. Location: Tulsa, Okla. Aircraft damage: Substantial.
What reportedly happened: According to the CFI, the landing gear was lowered during slow flight, then retracted. When the pilots returned to the airport and lowered the landing gear in preparation for landing, flames erupted from under the instrument panel and the carpet on the floor caught fire.
The pilots declared an emergency before the radio failed. They pulled the mixture control to the idle cutoff position, but the fuel selector could not be turned off due to the flames. The cabin filled with smoke. The CFI, who was sitting in the left seat, took control of the airplane. He opened his door, causing the airplane to yaw to the left, and he used right rudder to compensate, while the rudder pedals were engulfed in flames. In the ensuing forced landing, the instructor was able to avoid power lines but was unable to clear a fence. The airplane collided with a fence.
Examination of the airplane revealed that the terminal lug on the hydraulic pump was improperly covered and had shorted out. Additionally, the installation procedures for the hydraulic pump did not provide clear guidance on the proper method to cap the terminal lug.
Probable cause: A shorted terminal lug on the landing gear hydraulic pump, which resulted in a cabin fire. Contributing to the accident was the lack of clear installation procedures for the hydraulic pump.
For more information: NTSB.gov. NTSB Identification: CEN10LA572