Event Sequence
During the takeoff/initial climb, a "pop-bang" was heard when the main landing gear retracted. The two green main landing gear indicator lights and the red in-transit indicator light remained illuminated. The pilot recycled the landing gear, but could not obtain a down and locked indication for the nose landing gear. During a low approach over the runway, company personnel observed that the nose landing gear was not locked in the down position and was at a 45-degree angle. Subsequently, the nose landing gear collapsed during the landing roll.
Component Examination
The nose landing gear plunger assembly, part number 35-825094-4, had accumulated 10,872.5 hours of service. Stereoscopic and metallurgical examination of the component revealed a fatigue fracture.