What happened
On 10 May 2008, a Cessna 310Q, registration N850KF, was performing a private flight approach to Jersey Airport via an ILS/DME approach to Runway 27. During the approach, approximately 3.5 miles from the airfield, the pilot noticed that the green light indicating the right main landing gear was locked down failed to illuminate.
Following the lack of visual confirmation, the pilot initiated a go-around. After ensuring it was safe, the pilot replaced the light bulb, but the indication remained unchanged. Subsequent attempts to deploy the gear using both the standard and emergency extension systems were unsuccessful. In an effort to force the gear into the locked position, the pilot attempted to sideslip the aircraft, but the gear remained unconfirmed.
Believing the gear had not locked, the pilot proceeded with a visual approach using full flaps and a reduced speed. To avoid applying brakes that might cause the aircraft to veer, the pilot held the aircraft straight during the touchdown. However, as the mixture controls were moved toward the closed position, the right wing began to drop. The aircraft subsequently made contact with the runway, causing damage to the right wingtip, flap, aileron, and propeller.
The investigation
Investigators examined the landing gear mechanism to determine why the right main gear failed to lock. The inspection revealed that a specific link within the retraction and extension mechanism had failed. This component was designed to withstand only the loads associated with the movement of the gear, rather than the stresses of ground operations.
Post-accident testing of the gear's movement showed that the right leg operated with significant stiffness. This difficulty in movement was traced back to inadequate lubrication of the pivot bearings.
Findings
- A link in the right main landing gear mechanism suffered an overload failure.
- The failure occurred because the component was subjected to ground loads it was not designed to sustain, as the gear had failed to reach the fully locked position.
- The right landing gear was operating stiffly due to poor lubrication of the pivot bearings, which prevented the leg from reaching its fully extended position.