Primary finding
Probable cause
The pilot's inability to maintain directional control during the landing roll out due to a binding left brake master cylinder.
Investigator assessment
Analysis narrative
The pilot said that after touchdown he applied some left brake pedal to aid in maintaining directional control as the aircraft slowed. The pilot stated that when he released the brake pressure the left brake pedal remained depressed with that brake still activated. The pilot said he was able to maintain some directional control by using right brake pressure and rudder; however, as the aircraft slowed, the corrective actions became less and less effective and the aircraft eventually ran off the left side of the runway and ground looped. The operator reported that a post accident examination revealed that the left brake master cylinder had malfunctioned and would bind when the pedal was depressed.
Source record
Factual narrative
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