Accident Overview
A private pilot experienced a loss of braking effectiveness after landing on runway 27, a turf strip measuring 2,088 feet by 130 feet. The approach and touchdown were uneventful, but when the pilot depressed the toe brake pedals, the airplane did not decelerate. Although he felt pressure through the pedals, braking performance was absent. He repositioned his feet and tried again with the same result.
Sequence of Events
Realizing the airplane would run off the end of the runway, the pilot shut down the engine and turned off the master electrical switch. He reported "standing on the brakes as hard as possible" as the airplane impacted an airport perimeter fence, traversed a ditch, and came to rest on a nearby road. Subsequently, the airplane was struck by a vehicle traveling on the road.
Damage and Examination
The airplane sustained substantial damage to both wings and the engine firewall. Examination of the turf runway after the accident revealed no skid marks that could be associated with the airplane's ground track. Local law enforcement determined that the airplane touched down with 1,072 feet of runway remaining.
Performance Considerations
According to the airplane's operating handbook, at maximum gross weight, the airplane required about 600 feet to stop on a paved, level, dry runway. The handbook did not provide landing performance data for a turf runway. Local weather observations indicated a surface wind from the west-northwest at 9 knots.
Brake System Details
The airplane was equipped with a hand brake and dual toe brakes. The hand brake could also be used as a parking brake in conjunction with a locking ratchet system. When the hand brake lever is engaged, the use of toe brakes becomes ineffective. During a postaccident examination, with the hand brake fully disengaged, the left brake system functioned properly when its corresponding toe brakes (pilot and co-pilot positions) were depressed. The right brake assembly had impact damage that prevented a functional test.
Pilot Statement
The pilot stated that he had used the parking brake earlier in the day, but he had alternatively used the toe brakes during the engine run-up before departing on the accident flight. He concluded that the parking brake must have "partially engaged" sometime during the flight.