Incident Description
During the landing sequence, the pilot moved the landing gear handle to the extend position prior to touchdown. All three green gear-down indicator lights illuminated, indicating that the landing gear was extended and locked. However, after the main wheels touched down, as the nose was lowered, the nose gear collapsed.
Investigation Findings
An investigation was conducted to determine the cause of the collapse. It was found that the rod end (part number MS2124254K) on the nose gear actuator had failed due to fatigue. Further examination revealed that the failed component was not manufactured to meet the required specification. The microswitch that provides the nose gear down indication is located on the nose gear actuator and is activated when the actuator extends to the down position. This means that even though the microswitch was activated—giving a green light—the rod end was already weakened and subsequently failed under load during the landing roll.
The failure of the rod end allowed the nose gear to retract or collapse when weight was applied, despite the earlier indicator showing the gear as down and locked.