This October 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: Grumman G164. Injuries: None. Location: Edson, Ga. Aircraft damage: Substantial.
What reportedly happened: During a routine agricultural application flight, the pilot noted that the right rudder pedal felt soft. He returned to the airport at the conclusion of the flight and, just after touchdown, applied pressure to both brake pedals to stop the airplane. While the left brake operated normally, the right brake was ineffective and the plane went off the runway.
A post-accident examination revealed evidence of brake fluid leakage at the internal fuselage hydraulic line fitting. No reliable determination of the brake fluid quantity prior to the accident could be made as the right brake system had been compromised during the accident, but testing of the system with replacement fluid lines showed normal operation.
Probable cause: Leakage of hydraulic fluid from the internal fuselage line fitting, resulting in a subsequent loss of the right brake’s effectiveness.
For more information: NTSB.gov. NTSB Identification: ERA11LA011