What happened
During the initial climb phase following takeoff, the pilot received an unsafe gear warning immediately after the landing gear was retracted. The crew attempted to rectify the situation by recycling the gear four times. During these initial cycles, the pilot maintained down and lock indications for all three landing gear components.
However, following the fourth cycle, all gear indications were lost. The pilot attempted to deploy the nose gear using the emergency gear extension system, but the indication did not return. To verify the status of the aircraft, the pilot performed a low pass over the airport, during which air traffic control personnel visually confirmed that the nose gear was not extended. Consequently, the pilot proceeded to land the aircraft with the nose gear up.
The investigation
An examination of the nose gear assembly revealed that the nose gear shock strut was collapsed approximately three-quarters of an inch from its full extension. This partial collapse prevented the strut from engaging the uplock during the retraction sequence and prevented the deactivation of the unsafe warning during extension attempts. It was also determined that the partially extended strut could make improper contact with the uplock, which restricted the movement of the strut. Further disassembly of the assembly confirmed the incorrect installation of two internal seals, a condition that prevented the strut from extending to its full length.