Small Diameter Bomb

The GBU-39 Small Diameter Bomb (SDB) is a 250 lb (110 kg) precision-guided glide bomb that is intended to provide aircraft with the ability to carry a higher number of more accurate bombs. Most US Air Force aircraft will be able to carry (using the BRU-61/A rack) a pack of four SDBs in place of a single 2,000 lb (907 kg) bomb.

The Small Diameter Bomb II (SDB-II) / GBU-53/B, scheduled to enter production in January 2014, will add a tri-mode seeker (radar, infrared homing, and semiactive laser guidance) to the INS and GPS guidance of the original SDB.

Description

The original SDB is equipped with a GPS-aided inertial navigation system to attack fixed/stationary targets such as fuel depots, bunkers etc. The second variant (Raytheon's GBU-53 SDB II) will include a thermal seeker and radar with automatic target recognition features for striking mobile targets such as tanks, vehicles, and mobile command posts.

The small size of the bomb allows a single strike aircraft to carry more of the munitions than is possible utilizing currently available bomb units. The SDB carries approximately 38 lb (17 kg) of AFX-757 high explosive. It also has integrated "DiamondBack" type wings which deploy after release, increasing the glide time and therefore the maximum range. Its size and accuracy allow for an effective munition with less collateral damage. Warhead penetration is 3 feet (0.91 m) of steel reinforced concrete and the fuze has Electronic safe and fire (ESAF) cockpit selectable functions, including air burst and delayed options.

Air force

An air force, also known in some countries as an air army, is in the broadest sense, the national military organization that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an army, navy, or a marine corps. Typically, air forces are responsible for gaining control of the air, carrying out strategic and tactical bombing missions, and providing support to land and naval forces.

The term "air force" may also refer to a tactical air force or numbered air force, which is an operational formation either within a national air force or comprising several air components from allied nations. Air forces typically consist of a combination of fighters, bombers, helicopters, transport planes and other aircraft.

Many air forces are also responsible for operations of the military space, intercontinental ballistic missiles (ICBM), and communications equipment. Some air forces may command and control other air defence assets such as anti-aircraft artillery, surface-to-air missiles, or anti-ballistic missile warning networks and defensive systems. Some nations, principally Russia, the former Soviet Union and countries who modelled their militaries along Soviet lines, have an air defence force which is organizationally separate from their air force.

Bomb

A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanical stress, the impact and penetration of pressure-driven projectiles, pressure damage, and explosion-generated effects. Bombs have been in use since the 11th century in Song Dynasty China.

The term bomb is not usually applied to explosive devices used for civilian purposes such as construction or mining, although the people using the devices may sometimes refer to them as a "bomb". The military use of the term "bomb", or more specifically aerial bomb action, typically refers to airdropped, unpowered explosive weapons most commonly used by air forces and naval aviation. Other military explosive weapons not classified as "bombs" include grenades, shells, depth charges (used in water), warheads when in missiles, or land mines. In unconventional warfare, "bomb" can refer to a range of offensive weaponry. For instance, in recent conflicts, "bombs" known as improvised explosive devices (IEDS) have been employed by insurgent fighters to great effectiveness.