GAA18CA432

According to the pilot receiving instruction, during instrument training, she and the flight instructor noted that the left brake was less effective than the right brake during landing. Following the training, the pilot receiving instruction returned to her home airport, and during landing on the wet, grass runway, she executed a go-around because there was insufficient runway to safely stop the airplane. During the second landing, the airplane touched down with about two-thirds of the 2,600-ft-long runway remaining. During the landing roll, the pilot receiving instruction ensured that the throttle was in the idle position, and she retracted the flaps and applied aft pressure to the yoke. She applied the foot brakes and then the hand brake and again noted that the left brake was less effective than the right brake, and the airplane continued to slide on the wet grass. The airplane overran the runway and impacted a drainage culvert. Subsequently, the right wing struck a barn, and the left wing struck a trailer. The airplane sustained substantial damage to both wing's spars and ribs. According to the Federal Aviation Administration aviation safety inspector who examined the airplane, there was a pool of hydraulic fluid on the ground that appeared to be consistent with an O-ring failure or displacement. He affirmed that, although degraded, the brake would still have been functional but would have required more input by the pilot to build pressure within the brake line.

According to the pilot, she had flown from her home airfield to another airport to receive instrument training. The departure to, and arrival at, the other airport had been uneventful, however during the training she and the instructor noted that the left brake was less effective than the right brake. The brakes had been serviced two days prior to the flight. Following the training, she returned to her home airport, and during landing on the wet grass runway, she aborted the landing because there was insufficient runway to safely stop the airplane. During the second landing she touched down with about 2/3 of the 2,600-foot-long runway remaining. During the landing roll she ensured that the throttle was in the idle position, and she retracted the flaps, and applied aft pressure to the yoke. She applied the foot brakes and then the hand brake, and again noted that the left brake was less effective than the right, but the airplane continued to slide on the wet grass. The airplane overran the runway and encountered a drainage culvert. Subsequently, the right wing struck a barn, and the left wing struck a trailer. The airplane sustained substantial damage to both wing's spars and ribs. According to the Federal Aviation Administration, Aviation Safety Inspector that examined the airplane, there had been a pool of hydraulic fluid on the ground that appeared to be consistent with an O-ring failure or displacement. He affirmed that although degraded, the brake would have been functional yet requiring a pumping action by the pilot to build pressure within the brake line. Two days prior to the accident, the pilot's grandfather noticed that the airplane had a "soft left brake." He flew the airplane to a maintenance facility and the brakes were serviced by adding brake fluid to the brake system and the brakes were blead. The grandfather flew the airplane home and was satisfied with the brake operation.