Excessive wear on the aircraft adapter and the fuel nozzle poppet will result if the handle is allowed to float in the unlocked position. Once fuel flow has been established, test the aircraft’s precheck system (qualified squadron person- nel). Fuel the aircraft as directed by the plane captain. The plane captain monitors aircraft vents, tank pressure gage(s), and/or warning lights as necessary. When directed by the plane captain, release the dead man control. Rotate the nozzle flow control handle into the OFF and fully locked position (nozzle operator, and verified by the station operator). Failure to lock the flow control handle in the OFF position might result in a fuel spray or spill. Disconnect the nozzle from the aircraft adapter (nozzle operator). Stow the pantograph or hose (nozzle operator and station operator). · · Complete the paperwork (nozzle and station op- erator). Make sure the area is clear of equipment and personnel. MULTIPLE-SOURCE REFUELING Normally only one refueling truck at a time is used to service aircraft. However, there are situ- ations when multi-truck or truck and hydrant serv- icing is considered desirable, especially when very large aircraft must be refueled. The advantage of multiple-source refueling is reduced aircraft turn- around time. The aircraft’s NATOPS manual or equivalent aircraft servicing manual should be con- sulted for specific guidelines and instructions on multiple-source refueling before such operations are performed. PIGGYBACK REFUELING Piggyback refueling is a special refueling process sometimes used to refuel very large aircraft such as C-5As or E-6As. Two or more refueling trucks are used. One truck is attached to the aircraft’s refueling adapter, and other trucks are used to refuel this truck while it continuously refuels the aircraft, This is a potentially dangerous operation and will be con- ducted only with properly configured vehicles and under the direct supervision of the Fuels Maintenance Officer. REFUELING AIRCRAFT WITH AUXILIARY POWER UNIT (APU) RUNNING The aircraft’s APU may be used to supply elec- trical power for pressure refueling on military air- craft so equipped. This operation is not considered “hot refueling.”   However, the following precau- tions are observed in addition to the normal refuel- ing procedures: One man remains outside the aircraft within 10 feet of the APU exhaust with a fire extin- guisher of the size specified by the station’s Fire Chief. The fuels operator verifies that the aircraft is grounded. One person is at the GTC controls in the cockpit. Communications are established between the cockpit and the personnel performing the refuel- ing, to ensure immediate shutdown in an emer- gency. Personnel near the aircraft must wear sound-attenu- ating ear protectors. DEFUELING AIRCRAFT As was stated in chapter 5, defueling is one of the most technically demanding and potentially danger- ous operations performed by fuels personnel. The following rules apply to every defueling operation performed on shore stations: 1. Aircraft defueling must be requested by an authorized representative of the squadron’s CO, using an Aircraft defueling Certificate similar to the one 7-23