AIRCRAFT ROCKET LAUNCHERS

Aircraft rocket launchers (pods) carry and provide a platform to fire rockets. Launcher design permits multiple loading and launching of 2.75-inch and 5.0-inch rockets. Rocket pods let rocket motors (and, in some cases, completely assembled rounds) stay in the same container from their manufacture, through stowage, to their final firing. Aircraft rocket launchers are classified as either 2.75-inch or 5.0-inch. They may be further classified as either reusable or nonreusable. Launcher tubes that are constructed of metal are considered reusable and are usually returned for reloading. Under certain conditions, they may be jettisoned at the pilot's discretion. The 2.75-inch rocket launchers currently in use are the LAU-61C/A and LAU-68D/A. Characteristics and specifications for these launchers are listed in table 2-4. For detailed information about the LAU-61 and LAU-68 series launchers, refer to Aircraft Rocket Systems 2.75-inch and 5.0-inch NAVAIR 11-75A-92. The 5.0-inch rocket launchers are the LAU-10B/A, LAU-10C/A, and the LAU-10D/A. Characteristics and specifications for these launchers are listed in table 2-5. For detailed information on the LAU-10 series launchers, you should refer to Aircraft Rocket Systems 2.75-inch and 5.0-inch NAVAIR 11-75A-92.

The rocket launcher-shipping configuration shown in figure 2-16 is typical of all launcher-shipping configurations, except for the RF barriers.

The launcher center section is a cylindrical construction of 4, 7, or 19 tubes held together by a supporting framework, and it is covered with an aluminum skin. The center section houses or supports ll other components of the launcher. The center section for the LAU-10 (series) allows either 14-inch or 30-inch suspension. The center section for the LAU-61 and LAU-68 (series) provides for 14-inch suspension only.

The shipping ends are a multipurpose arrangement that consists of a shockpan assembly, a shockpan cover assembly, and/or locking ring assembly. An alternate hole and pin arrangement on the top and bottom is arranged so that the shockpans interlock when the launchers are stacked. The cover is equipped with a rubber seal ring that, when compressed by the locking ring assembly,  forms a watertight closure over the end of the launcher.

RF/Thermal barriers consist of a molded, expanded, polystyrene bead base with an aluminum foil coating cemented to the outer surface. RF/Thermal barriers are used on 2.75-inch pods to prevent the entry of electromagnetic radiation into the rocket igniter circuit. Equally important is the barrier on the aft end of the pod. It prevents exposure of the igniter lead contact. The LAU-61 and LAU-68 use the aft barrier only. The barriers remain installed for flight and are removed by impact or blast when the rocket is fired.

Rocket launcher packages have several components that are common to all or most launcher packages. Any notable differences are pointed out in the following discussion. 

Fairings

Frangible fairings (fig. 2-17) are made of an impregnated molded fiber designed with a waffle- or grenade-type structure that shatters readily upon rocket impact or from a blast. The fairings fit flush with the outside surface of the center section and form an aerodynamically smooth joint. The forward fairing consists of a one-piece molded section that disintegrates on rocket impact. The tail fairing for the LAU-10 (series) (fig. 2-17, view A) is molded in two sections (nose and base). The rocket blast shatters the nose portion. The base section remains on the launcher and acts as a choke or funnel to direct debris away from the aircraft. The tail fairings for the LAU-61 and LAU-68 (series) are distinctively different in appearance (fig. 2-17, view B). They are made of aluminum and are open on both ends. They function in the same manner as the base section of the tail fairing for the LAU-10 (series). Fairings are not shipped with the rocket launcher packages. They must be ordered separately and are received in sets packaged in cylindrical-shaped cardboard fairing containers (fig. 2-16). Fairings are not used in all applications. You should review the specific aircraft tactical manual for any restrictions in their use.

A breaker switch is used on all rocket launchers.The breaker switch is a safe-arm device that prevents loaded rockets from firing. It is usually located on the top of the center section of the launcher between the aft end and the aft electrical receptacle. With the detent pin installed in the breaker switch, the electrical system is grounded in the safe position and the rockets won't fire. The detent pin has a REMOVE BEFORE FLIGHT red streamer attached. Pull the pin immediately before the aircraft takes off and install it immediately after the aircraft lands. Install the detent pin in the breaker switch before loading the launcher with rocket motors. Keep detent pin installed, except during actual flight, until the launcher is downloaded and/or verified as being empty.

The mode selector switch is used on all launchers. The switch is located in the aft bulkhead of the launcher. The switch permits preflight selection of either ripple or single firing of the rockets by controlling the functioning of the pod intervalometer. 

Intervalometer

The intervalometer for the LAU-10 (series) pods is located in the forward bulkhead of the center section and in the aft bulkhead for the LAU-61 and LAU-68 (series). Intervalometers, whether installed in 5.0-inch or 2.75-inch launchers, perform the same function. If the mode selector switch is in the SINGLE fire position, the intervalometer fires one rocket on each firing pulse. If the mode selector switch in the 19-shot pod is in the SINGLE fire position, the intervalometer fires the rockets in pairs. If the mode selector switch is

The LAU-10 (series) launchers are reusable launchers intended for shipping (without warheads), stowing, and firing four 5.0-inch rockets. When loaded with four completely assembled rounds, the total weight varies with rocket configuration from 500 to 550 pounds. The rockets are retained in the launcher tubes during shipping, handling, and flight by engagement of a spring-loaded detent pawl in the rocket detent groove (fig. 2-18). When the rocket is loaded and unloaded, a detent lift tool is used to raise and lower the detent pawl by rotating the detent lift handle, which is located at the forward end of the launcher. The detent also supports the firing pin. Each firing pin (fig. 2-18) is part of the detent assembly and is raised and lowered concurrent with the pawl. The firing pin extends into the tube and contacts the rocket firing contact band, which is located aft of the rocket detent groove. When the switch in the aircraft firing circuit is closed, electrical current flows from the aircraft firing circuit through the electrical receptacle, safety switch, mode selector switch, intervalometer, and the firing pin in the launcher to the contact band in the forward end of the motor, and through the lead wire to the squib in the igniter. The current entering the rocket squib heats the squib primer mixture, which, in turn, ignites the igniter charge. Pressure within the igniter unseats a blowout plug, permitting the burning charge to ignite the propellant grain. The whole process of ignition requires about 0.005 second. Pressure of the hot propellant gases from the burning grain bursts the nozzle seal and provides the thrust to propel the rocket. Thrust overrides the detent spring, releasing the pawl from the rocket detent groove. The thrust then pushes the rocket out the forward end of the tube. The impact from the first rocket out shatters the forward fairing and the blast removes the tail fairing.

The 2.75-inch (series) launchers are intended for shipping (in some cases, with warheads installed) stowing, and firing the 2.75-inch rockets. The weight of loaded launchers varies, depending upon the number of rockets installed and rocket configuration. The rockets are retained in the launcher tubes during shipping, handling, and flight by engagement of a leaf-spring type of detent with integral blast paddles.

 During loading, the rocket motor depresses the detent until the detent  snaps into the detent grooves located on the aft end of the motor. To remove rocket motors, use a rocket loading and release tool to depress the detent. A spring-loaded firing contact (fig. 2-20) is located in the end of each tube. The principles of operation for the 2.75-inch launcher are basically the same as the 5.0-inch launcher. The 2.75-inch launcher can be loaded with less than 7 or 19 rockets when tactical requirements exist. However, you should refer to the specific tactical manual and aircraft-loading manual. Also, since the rockets are fired in a definite sequence, the rockets must be loaded into the launcher tubes in the proper sequence. Airborne rocket loading procedures, including electrical test procedures, are covered later in this manual.