GAA15CA242

The pilot reported that after a simulated rope break maneuver while towing a glider, he maneuvered to the runway and landed "normal". The pilot reported that during the landing roll the airplane "yawed" to the left; he applied right rudder inputs to correct the yaw, but it was ineffective. The pilot reported that he "quickly applied right brake", but "felt no brake pressure in the pedal". He "pressed the brake pedal 4-5 times as the aircraft continued to yaw", subsequently the airplane ground looped to the left. The airplane sustained substantial damage to the right wing and the fuselage. The pilot reported that when he applied the right brake he "heard the pedal click against something behind it, creating a metallic sound." A post-accident examination of the right brake system components revealed, that the brake disc was within limits, and brake pads were within limits. The aluminum hydraulic brake line tube which is lead along the aft edge of the gear leg from the brake caliper toward the master cylinder was broken about halfway down the gear leg, under the retaining bracket. The retaining bracket was canted and the brake line and rubber padding had been secured with a zip tie. There were no signs of impact damage at the break. In a statement from the airplane's type certificate holder to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) dated October 14, the holder reported that at the point where the zip tie had been installed, the brake line was supposed to be held in place by a green bracket, with the small section of rubber tube protecting the line from direct contact with the other metal parts. The green bracket should be positioned perpendicular to the aft contour line of the gear leg. It is likely that the canted bracket and zip tie created a pinch point on the flexing gear leg and resulted in the failure of the brake line.

The pilot reported that after a simulated rope break maneuver while towing a glider, he maneuvered to the runway and landed "normal". The pilot reported that during the landing roll the airplane "yawed" to the left; he applied right rudder inputs to correct the yaw, but it was ineffective. The pilot reported that he "quickly applied right brake", but "felt no brake pressure in the pedal". He "pressed the brake pedal 4-5 times as the aircraft continued to yaw", subsequently the airplane ground looped to the left. The airplane sustained substantial damage to the right wing and the fuselage. The pilot reported that when he applied the right brake he "heard the pedal click against something behind it, creating a metallic sound." A post-accident examination of the right brake system components revealed, that the brake disc was within limits, and brake pads were within limits. The aluminum hydraulic brake line tube which is lead along the aft edge of the gear leg from the brake caliper toward the master cylinder was broken about halfway down the gear leg, under the retaining bracket. The retaining bracket was canted and the brake line and rubber padding had been secured with a zip tie. There were no signs of impact damage at the break. In a statement from the airplane's type certificate holder to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) dated October 14, the holder reported that at the point where the zip tie had been installed, the brake line was supposed to be held in place by a green bracket, with the small section of rubber tube protecting the line from direct contact with the other metal parts. The green bracket should be positioned perpendicular to the aft contour line of the gear leg.