The development of the GBU-12 traces back to the
Vietnam War. The U.S. Air Force wanted a greater variety of
laser-guided bombs, especially a lighter and more maneuverable one to be able to hit moving targets on the
Ho Chi Minh trail. Earlier designs of guided bombs such as the
BOLT-117 were quickly superseded by the Paveway series of add-on kits for conventional bombs. GBU-12 bombs entered service in 1976 The GBU-12 has been used in numerous conflicts such as the
Gulf War;
F-111s destroyed 920 Iraqi tanks and APCs with GBU-12s. It is among the most commonly used guided munitions, and as such is able to be dropped from a very wide variety of aircraft, such as the
F-111,
B-52,
A-10,
F-15E,
F/A-18,
B-1B,
F-16C/D, and
F-35 (
GBU-49).
Guidance The
US Department of Defense has upgraded GBU-12 production versions to include
GPS guidance modes. Lockheed Martin is the sole source for US Navy purchases of this version. Raytheon sells upgraded GBU-12s to the US Government and 23 other nations.
Laser-guided bombs are often labeled "
smart bombs" because they are able to follow a non-ballistic trajectory when
laser designation of the intended target is undertaken. According to Raytheon's fact sheet for the Paveway II, 99 deliveries of
guided munitions will yield a
circular error probable (CEP) of only , versus a CEP of for 99
unguided bombs dropped under similar conditions. Paveway II laser-guided bombs use what is known as "
bang bang" guidance. This means the bomb's
fins deflect fully, rather than proportionally when attempting to guide to the laser spot. For example, if the laser spotting determines that change need to be made, the fins deflect until over-correction and then deflect back in the opposite direction, creating a
sinusoidal type of flight path. This type of guidance may be less efficient at times, however is more cost-effective and allows the use of simpler electronics in the guidance system. ==Operators==