WPR20LA172

Shortly after landing, the airplane veered left. The pilot used right rudder and applied right brake to counteract the turn, and the airplane began to straighten out. Immediately after, he felt that the right brake was not working, and the airplane again made an immediate turn to the left. The airplane exited the left side of the runway, the left-wing tip impacted the ground, and the airplane spun to the left, which resulted in a collapse of the left main landing gear and substantial damage to the left wing. An examination of the right brake assembly revealed that the center piston O-ring was damaged, and the right brake hydraulic fluid reservoir was empty. These discrepancies resulted in the loss of brake pressure and subsequent failure of the right brake.

On May 9, 2020, about 1210 Pacific daylight time, an Ayres Corporation S2R-G1 airplane, N2245S, was substantially damaged when it was involved in an accident near Imperial, California. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. The pilot reported that he had completed eight crop-dusting application loads and a rinse-load before returning to the home base of Imperial County Airport (IPL), Imperial, California. During the approach to runway 32, he entered the airport traffic pattern at a 45° right base entry and stated that everything was normal up to this point. Shortly after crossing the runway threshold, both main landing gear touched down on the runway and the airplane made an immediate turn to the left. He applied pressure to the right rudder pedal and right brake to counteract, and the airplane started to straighten out. Shortly after he felt that the right brake was not working, and the airplane again made an immediate turn to the left and exited the runway. The pilot then reported that after exiting the runway, the left wing tip impacted the ground, the airplane spun to the left, and the left main landing gear collapsed. The pilot also reported that the right main brake assembly had been leaking prior to the accident. The pilot provided a pre-accident photograph that showed a small puddle of brake fluid near the right main landing gear, where the airplane is normally parked. Examination of the accident site revealed that the airplane traveled over soft terrain and the left main landing gear struts buckled near the fuselage attach points. The left wing contacted the ground and was buckled across the midsection of the upper surface. The left wing had two ribs that were distorted, and the right main tire showed evidence of fluid streaks, consistent with a leaking brake assembly. During the examination of the brake assemblies, the right brake assembly had a damaged O-ring located on the center piston (see figure). The reservoir for the right brake assembly was also empty of brake fluid. Figure - Brake assembly disassembled. The pilot did not submit the National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report Form 6120.1.