History of the Flight
On 10 May 2008, at approximately 1030 UTC, the pilot of a Cessna 310Q (registration N850KF) was conducting a private flight and approaching Jersey Airport. While on an ILS/DME approach about 3.5 miles out, the pilot selected the landing gear down. The green gear-down-and-locked light for the right main landing gear failed to illuminate.
The pilot initiated a go-around and, when safe, replaced the light bulb, but the light remained off. He then attempted to lower the gear using both the normal and emergency extension systems, and tried sideslipping the aircraft to lock the gear down. These efforts were unsuccessful, and the green light for the right main gear stayed off, leading the pilot to conclude the gear had not locked down.
The pilot made a visual approach to Runway 27 with full flap and reduced speed to the blue-line figure. On rounding out, he held off until the stall warning occurred to achieve a gentle touchdown. He kept the aircraft straight, allowing it to slow without braking, hoping the right main gear would continue to support the aircraft. As he moved the mixture controls toward fully closed, the right wing began to drop. He then turned off the fuel, electrics, and magnetos. After the aircraft came to a halt, he exited via the main door.
Examination and Findings
Post-accident examination revealed that a link securing the right leg in the extended position had suffered an overload failure. The damage was consistent with the component, designed to carry only retraction and extension loads, being subjected to ground loads due to the landing gear not reaching the locked position. During retraction and extension tests after repairs, considerable stiffness in the operation of the right leg was noted. This stiffness was attributed to inadequate lubrication of the pivot bearings.
The right wingtip, flap, aileron, and propeller contacted the runway and were damaged.
Probable Cause
The right main landing gear failed to lock down due to stiffness in operation caused by inadequate lubrication of the pivot bearings, preventing the leg from reaching the fully extended position.