Accident Sequence
On August 1, 2018, about 1215 mountain daylight time, a Champion 7GCBC, registration N57477, veered off the runway and collided with a fence during the landing roll at Big Creek Airport (U60), Big Creek, Idaho. The airline transport pilot and passenger were not injured. The airplane sustained substantial damage to the right wing struts. The aircraft was owned and operated by the pilot under Title 14 Code of Federal Regulation Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The personal cross-country flight originated from Flying B Ranch, Cascade, Idaho at 1136 with a planned destination of Big Creek.
The pilot stated that after a normal landing on runway 19, he applied wheel brakes. The airplane immediately turned left, and despite application of brakes and right rudder, it veered off the left side of the runway. The airplane continued over a water sprinkler system, through a wood fence, and came to rest in a stand of small trees. The pilot noted he had never before had to brake as aggressively with this airplane.
A witness observed the airplane make a normal landing remaining aligned with the runway centerline. When he looked back momentarily, he saw the airplane in a gradual left turn at slow speed in a 3-point attitude. The airplane then collided with an airport perimeter fence and came to rest about 600 ft past the touchdown point.
Aircraft and Airport Information
The Champion 7GCBC was manufactured in 1993. The tandem seat, tail dragger design was equipped with flight controls in the rear seat, including rudder pedals. Brake pressure could be applied from either seat. Big Creek Airfield is an uncontrolled, public use airport. The dirt runway 01/19 is 3,550 ft long and 110 ft wide. When landing on runway 19, there is an uphill grade of 0.3 degrees. Runway 19 is the recommended landing runway. The runway surface was examined and found to be in good condition with no holes or defects.
Investigation Details
The pilot believed the brakes were malfunctioning by not applying equal brake pressure to the two brake calipers. He stated he was applying equal force to both brakes when the airplane veered left. The left brake line was breached during the accident sequence. A Federal Aviation Administration inspector from the Boise Flight Standards District Office monitored the replacement of the left brake line, then tested the left brake afterward. He reported the left brake functioned normally. A visual inspection of the left brake puck revealed normal conditions. There were no indications of brake anomalies present. The airplane was loaded onto a trailer at the time of the examination, so no other tests of the brakes could be performed. After the airplane was removed from the trailer, the owner, with authorization of the investigator-in-charge, checked both brakes and reported normal operation. A video of the accident sequence, as viewed from inside, shows the airplane landing, veering left, and coming to a stop in the stand of small trees.