Which hydraulic system controls the normal extension and retraction of the gear?

The hydraulic system responsible for the normal extension and retraction of the landing gear in the C-17 is the No. 3 hydraulic system. This system is specifically designed to manage landing gear operations, ensuring safe deployment and retraction when required during takeoff and landing phases of flight.

Understanding the functional distribution among the different hydraulic systems is crucial for pilots and crew members, as each system operates distinct components of the aircraft. The No. 1, No. 2, and No. 4 systems have their specific designated functions, which do not include the landing gear operation. Thus, effective management of the No. 3 hydraulic system is vital for the aircraft's ground handling capabilities.