The  Mk  71  Mods  spring-loaded  fin  (fig.  2-11)  deploy after emerging from the rocket launcher tube. They lock in place (open) by sliding into a locking slot in the flange at the aft end of the fin nozzle assembly. When not actually installed in the launcher, the fins are held in the closed position by a fin retainer band, which must be removed when the rocket is installed into the launcher tube. REVIEW NUMBER 1 Q1. List the two rockets currently used by the Navy. Q2. If a rocket does not fire when the firing circuit is energized, it is known as a _________ . CLOSED  -  IN  LAUNCHER  TUBE Q3. Q4. Q5. Q6. Q7. Q8. Q9. Q10. Q11. Q12. What is meant by the rockets thrust? In  rocket  propulsion,  the  Venturi  nozzle decreases  turbulence  of  escaping  gases  and increases   thrust.   Gas   pressure   inside   the container  provides  about  _______,    and  the escaping gases provide about ______ to move the container  forward. List the three components of a rocket. List  the  components  of  rocket  motors. What is the purpose of the inhibitor? What rocket component is salt coated to prevent unstable  burning  of  the  rocket  propellant? When   are   rockets   most   susceptible   to radio-frequency (RF) energy? Name the type of nozzle installed in the Mk 40 rocket motor. Explain the difference between the Mk 16 and Mk 71 rocket motors. When should you remove the fin retainer band on a Mk 71 rocket motor? Warheads     Different tactical requirements demand different types of rocket warheads be used with airborne rockets. Warheads are classified as either 2.75 inch or 5.0 inch warheads.  They  may  be  further  classified  as PARTIALLY  OPEN  -  LAUNCHED FULLY OPEN - SPINNING 60 RPS Figure 2-11.—Mk 71 Mods motor, nozzle, and fin assembly. high-explosive,  flechette,  smoke,  flare,  or  practice. Warheads  for  2.75-inch  rockets  are  normally  received with the fuzes installed. There are many different warheads, fuzes, and motor combinations available. Therefore, the following discussion   is   general. For   specific   component information,  you  should  refer  to  Airborne   Rockets, NAVAIR  11-85-5. High-explosive warheads contain high-explosive material (generally comp-B) surrounded by a metal case.  An  internally  threaded  nose  fuze  cavity  permits the installation of a nose fuze or an inert nose plug, depending on tactical requirements. Some warhead configurations require the use of a base fuze. Base fuzes are installed at the factory and should never be removed. High-explosive warheads are painted olive drab and may have a narrow yellow band around the nose. There are several types of high-explosive warheads, and each is designed for a specific type of target. HE-FRAG   WARHEADS.—   High-explosive fragmentation (HE-FRAG) warheads (fig. 2-12) are 2-8