Cub Crafters Inc CC19-215 N61KT accident near Mccall, Idaho

Probable cause

A loss of directional control during the landing roll due to a fractured brake line fitting on the brake caliper.

NTSB analysis

The pilot reported that he was attending a backcountry flying course and had conducted several off-airport landings on various backcountry airstrips prior to returning to the destination airport. During the landing roll, the left brake “flopped” under his foot with no pressure and the airplane veered to the right. The airplane exited the right side of the runway and traveled down an embankment, where the left wing and tail contacted the down-sloping terrain.

Examination of the brake caliper and brake line components revealed that the brake line fitting had fracture separated. A contact mark was observed on the brake caliper aft of the fitting. Metallurgical examination of the fracture surfaces on the brake line fitting revealed that it had fractured due to overstress. It is likely that, while operating on an unimproved surface, the brake line fitting struck an object that fractured the fitting. The loss of functionality in the left brake caused the loss of directional control during the subsequent landing.

Text from the NTSB. Open the NTSB docket for WPR22LA217 for the full record.