Final answer:
The Type III hydrant system lockout key is a specialized tool used in airport fueling operations to engage a lockout mechanism, ensuring the safety of personnel and aircraft by preventing unauthorized fuel system operation.
Step-by-step explanation:
The Type III hydrant system lockout key is a specialized tool used in airport fueling operations. This key is designed to engage a lockout mechanism on Type III hydrant pits, preventing unauthorized or accidental operation of the fueling system.
The safety of personnel and aircraft during refueling operations is the primary concern, and the lockout key ensures that fuel flow cannot be initiated unless the proper procedures are followed and the system is secured. In essence, the lockout key serves as a form of access control, allowing only trained and authorized personnel to operate the hydrant system.