How is the nose gear locked in the down position?

The nose gear is locked in the down position through an actuator and over-center action. This system ensures that when the nose gear is extended, the actuator pushes the gear into a position that locks it securely. The over-center action refers to the design whereby once the gear passes a certain point in its travel, it moves into a position that mechanically prevents it from retracting without intentional action. This design is crucial for ensuring the gear remains safely extended during landing and taxiing.

In aircraft systems, mechanisms like these are essential for reliability and safety, allowing pilots to have confidence in gear position during critical phases of flight. The use of an actuator means that hydraulic or electric energy operates the movement, while the over-center mechanism functions to provide a fail-safe locking mechanism that operates even if power is lost.