What happens when all three landing gear are down?

When all three landing gear are down, the hydraulic pump typically turns off to prevent unnecessary strain and to conserve hydraulic fluid. This is because the hydraulic system is primarily activated when the landing gear is being retracted or extended. Once the landing gear reaches the fully extended position and the landing gear lock sensors confirm that the gears are safely down and locked, there is no need for the hydraulic system to remain active, thus allowing the pump to turn off.

This mechanism plays a crucial role in maintaining the efficiency and longevity of the hydraulic system. Keeping the pump running when not needed can lead to increased wear and potential overheating, so it is designed to deactivate once the landing gear is secured in its down position.