Review of NTSB Investigations of Cessna 210 Hydraulic Actuator Fractures from Fatigue

The National Transportation Safety Board is an independent federal agency charged with investigating transportation accidents across aircraft, rail, pipeline, marine, highway, and hazardous materials platforms. Among these events, the agency has investigated multiple accidents of hydraulic actuators of Cessna 210 landing gear systems. Several of these components have fractured, causing a loss of hydraulic fluid pressure, resulting in the inoperability of landing gear systems required in emergency landings that often result in substantial damage to airplanes. While no pilots or passengers have been critically injured to date, the failure of these actuators presents a safety-of-flight issue. This presentation will detail the fatigue cracking that initiated from corrosion pits along a retaining ring groove of the actuator, leading to crack propagation and longitudinal splitting of the actuator piston barrel. The presentation will also discuss safety improvements and recommendation development to prevent the fracture sequence from reoccurring.