Failure analysis and improvement of brake accumulator pressure drops fast for certain type of aircraft

This paper presents a fault analysis of “brake accumulator pressure drops fast” for a certain type aircraft. By statistically analysis of the in-service fault information, combining an in-depth analysis of the accumulator's brake working principle, and conducting internal leakage tests and disassembly analysis on the brake shut-off valve, the root cause of the fault was identified. The fault was ultimately attributed to damage on the sealing surface of the shut-off valve caused by localized contaminants in the hydraulic system, leading to significant leakage between the pressure chamber and the return chamber, resulting in a rapid pressure drop in the brake accumulator. Two possible improvement measures were proposed. This case study can provide a reference for troubleshooting similar faults.