LAU-7/A

LAU-7/A (SERIES) GUIDED MISSILE LAUNCHER

The LAU-7/A (series) guided missile launcher is a reusable launcher that provides a complete launching system for use with the AIM-9 Sidewinder (series) missiles. The launcher (fig. 3-17) has four major assemblies—the housing assembly, nitrogen receiver assembly, mechanism assembly, and power supply.

Housing Assembly

The housing assembly is the main structural member of the launcher. It is an extruded, machined aluminum member that provides structural rigidity to the launcher and includes provisions for mounting all other assemblies. It also includes provisions for mounting the launcher to the aircraft.

Nitrogen Receiver Assembly

The nitrogen receiver assembly stores the high-pressure nitrogen (3,200 psig) used to cool the missile's IR detector in the guidance system. Two nitrogen receiver assemblies are available for use with the launcher. One is a cylindrical fiber glass container with a corrosion-resistant metal liner, and the other is a plain cylindrical steel container. The receiver mounts in the aft section of the housing assembly and screws into the aft end of the mechanism assembly. All receivers contain a charging valve (for refilling), relief valve, and a pressure indicator mounted in the aft end of the cylinder. The pressure indicator is color coded to ensure correct readings as follows:

• Red 0 to 2.2 psi

• Yellow 2.2 to 2.8 psi

• Green 2.8 to 3.5 psi

• White 3.5 to 5 psi

All readings listed must be multiplied by 1,000 psi.

Mechanism Assembly

The mechanism assembly is an electromechanical device that holds the missile for takeoffs and landings and releases the missile for launching. It mounts in the center of the housing assembly forward of the receiver assembly. The subassemblies of the mechanism assembly are discussed in the following paragraphs.

ELECTRICAL HARNESS ASSEMBLY

The electrical harness assembly consists of the appropriate connectors and wiring to interconnect between the aircraft power and firing circuits and the launcher.Also, the nitrogen system supply tube is routed through the electrical wiring harness to the power supply.

DETENT, DETENT LOCK, DETENT-LOCK SOLENOID, AND SNUBBERS

The detent, detent lock, detent-lock solenoid, and forward snubbers make up an electromechanical system that restricts longitudinal and lateral motion of the mounted missile. This system prevents accidental launch or release during catapult takeoff or arrested landings. A slotted detent wrench/safety pin is installed through the mechanism assembly to prevent movement of the aft detent and to safe the launcher firing circuits. It is also used to raise the aft detent lug sufficiently to clear the missile hanger during loading. The slotted detent wrench/safety pin is removed before flight. When the detent is down (normal), the striker points make contact with the buttons (contacts) on the forward hanger of the missile. The forward striker point does not have a function for the missile; the aft striker point makes contact between the missile and the firing safety switch.

NITROGEN CONTROL VALVE

The nitrogen control valve is a solenoid-operated shutoff valve that controls the flow of nitrogen from the receiver assembly to the missile. The pilot controls operation of the control valve from the cockpit.

Power Supply

One power supply is available for use in the launcher. Power supply PP-2581/A is a single-phase power supply. It is a self-contained unit with connectors on each end. The aft connector links the power supply and the mechanism assembly. The forward connector provides the connection to the missile's umbilical cable.

Forward Fairing Assembly

The forward fairing assembly is an aluminum casting that mounts to the forward end of the outer housing to provide an aerodynamic nose to the front of

Umbilical Hook Support Assembly

The umbilical hook support assembly mounts to the forward housing rails and, during missile loading, is connected to the missile umbilical shear block. At missile launch, the mechanism snaps up, retracting the sheared end of the umbilical cable into the launcher to prevent interference with the missile hangers.

Fin Retainer Assemblies

Two fin retainer assemblies are mounted to the forward end of the housing assembly beneath the forward fairing assembly. The fin retainer is a small, U-shaped bracket that contains two spring retainers that snap over the missile fins to prevent movement during captive flight.

Snubber Mount Fitting Assembly, Aft Fairing Latch Assembly, and Aft Fairing Assembly

The aft snubber mount fitting assembly, aft snubber assembly, and aft fairing latch are assembled together as a group and mounted to the aft end of the housing assembly. When the aft fairing latch assembly

is in the open position, you can access the nitrogen receiver. It also releases the aft snubbers to allow missile loading. When in the closed position, it allows the snubbers to spring over the aft missile hanger, locking it in place. For further information on the LAU-7/A (series) guided missile launcher, refer to Guided Missile Launcher LAU-7/A, NAVAIR 11-75A-54.