What happened
On 8 October 2003, a Cessna P210N Centurian, registration G-VMDE, was conducting a private flight from Cardiff Airport, Wales, to Abbeyshrule Airport, Eire. Following a routine takeoff and successful landing gear retraction, the aircraft climbed to approximately 3,000 feet. While northwest of Cardiff, the pilot experienced a loud bang and a physical thump originating from the rear of the fuselage.
Upon inspection via the port wing mirror, the pilot observed that the left main landing gear door was partially open. Simultaneously, the electrically driven hydraulic pump began operating continuously. To prevent further loss of hydraulic fluid, the pilot deactivated the pump via its circuit breaker and declared an emergency to return to Cardiff. The pilot successfully deployed the landing gear using the manual hand pump; however, the pump became limp immediately after the gear indicators showed green. The aircraft landed safely at Cardiff Airport.
The investigation
Post-flight inspections of the Cessual P210N Centurian revealed that the end cap of the main gear door accumulator had detached. This detachment caused a dent in the internal fuselage structure and displaced the accumulator body from its mounting. The investigation confirmed that the hydraulic reservoir was empty, with significant evidence of fluid leakage within the landing gear bay and on the fuselage side.
Findings
- The end cap of the main gear door accumulator, which is typically secured by a circlip, became detached during flight.
- The detachment of the accumulator end cap caused a loss of hydraulic fluid from the system.
- There was no evidence of recent maintenance performed on the accumulator component.
- The specific cause for the failure of the cap to remain in place was not established.