Incident Overview
During the initial climb after takeoff, the pilot reported that when the landing gear was retracted, an unsafe gear warning activated. After several unsuccessful attempts to correct the condition, including recycling the gear four times, the flight diverted to an alternate airport.
Gear Indication and Confirmation
Although the pilot had down-and-lock indications for all three gears during the recycling, after the fourth cycle there was no gear indication despite attempts to extend it using the emergency gear extension system. The pilot performed a low pass over the airport, where air traffic control personnel confirmed that the nose gear was not extended.
Landing and Examination
The pilot subsequently landed with the nose gear retracted (nose gear up). Examination of the nose gear assembly revealed that the nose gear shock strut was collapsed about three-quarters of an inch from full extension. This condition prevented the strut from engaging the uplock during retraction and prevented the deactivation of the unsafe warning during extension.
Further Findings
It was also determined that the partially extended strut could improperly contact the uplock, restricting the movement of the strut. Further disassembly confirmed the incorrect installation of the two internal seals, which would prevent the strut from extending fully.
Conclusion
The investigation concluded that the incorrect installation of internal seals led to the shock strut not extending fully, causing the unsafe gear warning and subsequent inability to confirm gear extension.