What safety device is actuated by the compression and extension of the landing gear strut

What safety device is actuated by the compression and extension of the landing gear strut

• A. Elevator trim
• B. Pitot heater
• C. ground safety switch
• D. Flap position sensor

Answer: (C)

When the landing gear strut is compressed by weight on the wheels, it actuates a ground safety switch (also called a squat switch). This switch provides a signal that the aircraft is on the ground, so systems that should operate only on the ground—such as engine start interlocks or ground-warning protections—can engage. When the gear is extended and there’s no weight on the wheels (in flight), the switch returns to its other state, indicating a flight condition. The other devices aren’t tied to the gear’s up/down movement: elevator trim controls pitch, the pitot heater keeps the pitot tube from icing, and the flap position sensor monitors flap angle.

When the landing gear strut is compressed by weight on the wheels, it actuates a ground safety switch (also called a squat switch). This switch provides a signal that the aircraft is on the ground, so systems that should operate only on the ground—such as engine start interlocks or ground-warning protections—can engage. When the gear is extended and there’s no weight on the wheels (in flight), the switch returns to its other state, indicating a flight condition.

The other devices aren’t tied to the gear’s up/down movement: elevator trim controls pitch, the pitot heater keeps the pitot tube from icing, and the flap position sensor monitors flap angle.