AIR-TO-GROUND  MISSILES The  Navy  is  currently  developing  two  new  air- to-ground  missiles,  the  Tacit  Rainbow  missile,  and the IR Maverick missile. However, these missiles are not yet operational. Air-to-ground missiles in current inventory include the Harpoon and Harm missiles. Harpoon The Harpoon missile discussed previously in this  chapter  under  surface-to-surface  missiles  can also  be  used  as  an  air-to-ground  missile.  Many naval  aircraft  are  capable  of  carrying  the Harpoon. Harm The Harm missile was designed to destroy or suppress   enemy   electronic   emitters.   It   was designed especially to suppress those associated with radar sites used to direct antiaircraft guns and surface-to-air missiles. Harm is a high-speed antiradiation  missile  that  succeeds  the  Shrike  and Arm  missiles  as  the  Navy’s  primary  defense- suppression   air-to-surface   missile.   The   Harm missile proved effective against Libyan targets in the  Gulf  of  Sidra  in  1986. Characteristics  of  Harm: Length: 13 feet, 8 inches Diameter: 10  inches Wing  span: 3 feet, 8 inches Weight: 807  pounds Speed: More than 760 miles per hour Range: More  than  50  nautical  miles OTHER  AIRBORNE  WEAPONS Other  airborne  weapons  used  by  naval  aircraft include  20-mm  guns,  rockets,  and  bombs. 20-mm Guns The only 20-mm gun now used by operational fleet  aircraft  is  the  internally  mounted,  six-barrel, M61A1   20-mm   gun. It   has   an   electrically controlled  and  hydraulically  operated  ammunition drum. The gun fires at a rate of 6,000 rounds per minute in the GUNHI position and 4,000 rounds per minute in the GUNLOW position. The AV-8B Harrier  uses  a  similar  25-mm  gun. Aircraft Rockets and Bombs The Navy is currently developing new rockets and   bombs   to   meet   today’s   operational   re- quirements.  The  new  advanced  rocket  system will  provide  a  high  volume  of  air-to-ground fire  from  standoff  ranges  against  a  broad target spectrum. The new advanced bomb family (ABF)   will   provide   two   bombs   to   meet   the general-purpose   bombing   requirements   for increased  blast,  fragmentation,  and  penetra- tion  effects.  The  ABF  will  replace  the  Mk 80-series   bomb   with   a   500-pound-class   bomb optimized  for  blast  fragmentation  and  a  1,000- pound-class   bomb   with   improved   penetration capabilities. ANTISUBMARINE   WARFARE WEAPONS The  Navy’s  primary  operational  weapons are  (1)  antisubmarine  rockets  (ASROCs),  (2) submarine   rockets   (SUBROCs),   and   (3)   tor- pedoes. ASROC The ASROC missile is a subsonic, shipboard- launched,  solid-fuel,  rocket-propelled,  anti- submarine  ballistic  projectile.  The  missile  has  two configurations-one  with  a  depth  charge  and  one with  a  torpedo. The purpose of the ASROC is the destruction of submarines at long ranges. To achieve this, it delivers a torpedo or nuclear depth charge through the  air  to  a  specific  point  in  the  water.  From that  point,  it  can  either  attack  under  the  most favorable  circumstances  or  have  the  submarine within  its  lethal  radius.  Because  of  its  stand- off   range,   the   ASROC   enables   the   antisub- marine  warfare  (ASW)  ship  to  launch  its  weapons before   the   submarine   discovers   it   is   under attack. ASROC launchers are installed in FFs, DDs, DDGs, and CGs. On most ships, the launcher is 20-11