Figure 10–5. Gravity Refueling/Defueling Major Component Location

TM 1-1520-238-T-7 10–14 10–2. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (cont) 10–2 d. Nitrogen Inerting System. The nitrogen inerting system (fig. 10–4) consists of the nitrogen inerting unit (NIU), the NITROGEN INERT MONITOR indicator and associated lines and fittings. (1) NIU. The NIU, located in the ammunition bay, utilizes pressurized air from the pressurized air manifold and purges about 70% of the oxygen present. This air is then regulated into the aft fuel cell and onward into the forward fuel cell. (2) NITROGEN INERT MONITOR Indicator. The NITROGEN INERT MONITOR indicator, located on the aft avionics bay, displays normal system operation or system failure. It also provides a PRESS TO TEST pushbutton for simulated system testing. e. Gravity Refueling/Defueling System. The gravity refueling/defueling system (fig. 10–5) consists of the gravity filler ports is located on the right side of the fuselage. The gravity filler port consists of a cap assembly that provides access to the gravity filler port, a gravity filler neck which provides an attachment point for the cap assembly, and a refuel/defuel check valve which has a flapper valve (installed within the valve housing) that is spring-loaded to the closed position. The flapper valve provides a means of sealing the gravity port to allow for pressurizing the fuel cell with nitrogen. M70-289A GRAVITY FILLER NECK CAP ASSEMBLY GRAVITY FUELING REFUEL/DEFUEL CHECK V ALVE REFUEL/DEFUEL CHECK V ALVE CAP ASSEMBLY Figure 10–5. Gravity Refueling/Defueling Major Component Location f. Pressure Refueling/Defueling System. The pressure refueling/defueling system (fig. 10–6) consists of the refueling panel, the pressure refueling/defueling manifold, the fuel transfer (refuel) valve, the fuel level control valve, the air/vent pressure relief valve, and the fuel vent shutoff valve. (1) Refueling Panel. The refueling panel, located on the right side of the fuselage, provides a means of controlling refuel operations and monitoring fuel quantity during refueling, and allows the crew to pre-check automatic fuel shutoff. To allow refueling operations without having to gain access to the crew station, power is supplied by the battery to the FUEL QTY indicator switch and REFUEL VALVE switch.