bottle and the ECU are mounted on top of the launcher assembly. A servicing valve is provided, on the left-hand side of the helicopter, for servicing the air bottle. The air bottle should be serviced to 1200-1250 psi. This ensures that the system will be able to launch all 25 sonobuoys. The distributor valve assembly uses a stepping motor to route air pressure to the selected launch tube. A manual selection knob, distribution lock, and tube-selected indicator window are located on the valve. The manual selection knob can be hand rotated to move the rotary valve to vent or to any desired launcher tube position. The valve lock allows the rotary valve to be manually secured to any desired launcher tube position or vent. The tube-selected indicator window displays the position of the rotary valve at any one of 25 tubes or vent. The ECU front panel contains three controls and one indicator. The controls are a AUTO/MANUAL switch, a SELF TEST switch, and a SAFE switch. The indicator is a STATUS display. When the AUTO/MANUAL switch is in the AUTO position, the ECU controls the rotary valve. In the MANUAL position, the rotary valve is controlled by manually turning the manual selection knob. Depressing the SELF TEST switch initiates the BITE testing for the ECU and the launcher. The STATUS indicator displays any faults found during self-test. If more than one fault is found, the failure codes will cycle at 3-second intervals. The SAFE switch causes the rotary valve to move to the vent position. FIXED-WING KILL STORE SYSTEMS The kill store system consists of all equipment necessary to select, arm, and release weapons from the bomb bay(s) and wing stations of the aircraft. The system is divided into two subsystems—the bomb bay and the wing store systems. Bomb Bay System The bomb bay system consists of the units and components necessary for the carrying, arming, and releasing of stores. On the P-3C, these stores are installed on bomb racks suspended from removable pylon assemblies, which are mounted across the center of the bomb bay. On the S-3A, the racks are attached to brackets mounted to the aircraft in a cruciform pattern. Each of these basic installations is assigned a station number. Numbers followed by letters (such as A or B) designate these stations for special capacities or types of stores. In addition, these stations are arranged in pairs: stations 1 and 2, stations 3 and 4, etc. As a further identification feature on the P-3C, the stations are grouped into two layers. Odd numbered stations in the upper layer and even numbered stations in the lower layer. When the bomb bay is loaded with mixed stores, each pair of stations must be loaded with the same type of store to ensure proper clearance between the stores. The S-3A has only one layer of stations because of its much smaller bomb bays. The bomb bay doors are electrically controlled and hydraulically operated. For ground maintenance without power, the doors may be opened or closed internally on the P-3C by a manual control valve and hand pump. On the S-3A, the doors can be operated externally with a 3/8-inch drive crank. Both aircraft have a ground safety pin that is used to disable the door mechanism in the open position. The door safety pin must be inserted when personnel are working in the bays. The release of bomb bay stores is normally accomplished by the computer. In the P-3C, the TACCO performs programming, and the pilot or TACCO controls the release. In the S-3A, the TACCO does both, with the copilot acting as backup. The pilots in both aircraft have final control because they must activate the master arm switch. Wing Store System The wing store system consists of the units and components necessary for carrying, arming, and releasing external stores. On the P-3C, these stores are suspended from 10 wing stations, numbered 9 through 18. On the S-3A, the stores are suspended from two wing stations, W5 (left) and W6 (right). 7-17