Rocket motors currently used in the 2.75 inch and 5.00 inch include the following components: motor tube, igniter, propellant grain, stabilizing rod, and nozzle and fin assembly.

Motor tube - Made from aluminum stock. Forward end contains the head closure and threaded portion for attachment of the warhead. The center section is the combustion chamber. Aft end is grooved internally to accept a lockwire which attaches the nozzle and fin assembly.

Igniter: Ignites the propellant grain.

Propellant grain: An internal burning, star perforation grain made from a double base propellant. Produces a nearly constant thrust level. External portion of the grain is covered with an inhibitor to prevent burning on the surface.

Stabilizing rod: Salt coated stabilizing rod in the perforation of the motor propellant grain prevents unstable burning of the propellant reduces flash and after-burning, which contributes to compressor stall and flame out of jet aircraft engines.

The nozzle and fin assembly basically consists of a: nozzle plate, four nozzle inserts, fin-actuating mechanism, four fins, fin retainer, and contact disc.

The 2.75 inch rocket uses three types of rocket motors the MK 4 mods, the MK 40 mods and the MK 66 Mod 2.

MK 4 Mods - Fired from fixed-wing aircraft.

MK 40 Mods - Fired from helicopters only.

MK 66 Mod 2 - Fired from helicopters and fixed-wing aircraft.

The 5.0 inch rocket uses one type of rocket motor the MK 71 Mods. Fired from fixed wing low and high speed aircraft and helicopters.

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