Accident Details
Following a routine landing, the pilot observed that the left wheel brake provided no braking response, and the brake pedal depressed fully to the floor. Attempts to maintain directional control were unsuccessful, and the airplane veered to the right, departing the paved surface and entering the grass area. Subsequently, the landing gear collapsed, bringing the airplane to a stop. Postaccident examination revealed structural damage to the left wing spar.
Examination Findings
A postaccident inspection of the aircraft's braking system confirmed that the left brake was inoperative. Investigators located a small hydraulic fluid leak at the shaft of the parking brake valve within the pressurized section of the cabin. The leak allowed air to enter the left brake line while the cabin was pressurized, which rendered the left brake ineffective during the landing roll.
Probable Cause
The official probable cause was determined to be a leaking parking brake valve, which allowed air to enter the left brake line and resulted in the eventual failure of the left wheel brake during the landing roll.