What is the purpose of the landing gear squat switch?

The landing gear squat switch serves a crucial role in determining whether the aircraft is on the ground or in the air. When the aircraft makes contact with the runway upon landing, the squat switch is activated by the weight of the aircraft, signaling that it is on the ground. This switch plays a vital part in the aircraft's systems, as it can influence various functions, such as enabling or disabling certain systems that should only operate when the aircraft is on the ground or in flight.

For instance, the landing gear indication lights and certain hydraulic systems may only be active when the switch indicates that the plane is on the ground, preventing operations when it could be unsafe. Understanding this function is essential for ensuring the proper operation of landing gear systems and overall aircraft safety.