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A general-purpose bomb is an air-dropped bomb intended as a compromise between blast damage, penetration, and fragmentation in explosive effect. They are designed to be effective against enemy troops, vehicles, and buildings.
General-purpose (GP) bombs use a thick-walled metal casing with explosive filler (typically TNT, Composition B, or Tritonal in NATO or United States service) comprising about 30% to 40% of the bomb's total weight. The British term for a bomb of this type is "medium case" or "medium capacity" (MC). The GP bomb is a common weapon of fighter bomber and attack aircraft because it is useful for a variety of tactical applications and relatively cheap.
General-purpose bombs are often identified by their weight (e.g., 500 lb or 230 kg). In many cases this is strictly a nominal weight (the counterpart to the caliber of a firearm), and the actual weight of each individual weapon may vary depending on its retardation, fusing, carriage, and guidance systems. For example, the actual weight of a U.S. M117 bomb, nominally 750 lb (340 kg), is typically around 820 lb (370 kg).
Most modern air-dropped GP bombs are designed to minimise drag for external carriage on aircraft lacking bomb bays.
In low-altitude attacks, there is a danger of the attacking aircraft being caught in the blast of its own weapons. To address this problem, GP bombs are often fitted with retarders, parachutes or pop-out fins that slow the bomb's descent to allow the aircraft time to escape the detonation.
GP bombs can be fitted with a variety of fuzes and fins for different uses. One notable example is the "daisy cutter" fuze used in Vietnam War era American weapons, an extended probe designed to ensure that the bomb would detonate on contact (even with foliage) rather than burying itself in earth or mud, which would reduce its effectiveness. (This was not the first instance of such devices. As early as World War II, the Luftwaffe was using extended-nose fuzes on bombs dropped by Stuka dive-bombers and other aircraft for exactly the same reason. A blast several feet above the ground is many times more effective and has a far greater radius than one that is delayed until the bomb is below the surface.)
GP bombs are commonly used as the warheads for more sophisticated precision-guided munitions. Using various types of seeker and electrically controlled fins turns a basic 'iron' bomb into a laser-guided bomb (like the U.S. Paveway series), an electro-optical guided bomb, or, more recently, GPS-guided weapon (like the U.S. JDAM). The combination is cheaper than a true guided missile (and can be more easily upgraded or replaced in service), but is substantially more accurate than an unguided bomb.
During WWII the British adopted a description of general-purpose bombs as medium capacity (MC) bombs. The 1,000 lb (450 kg) MC was developed from 1942 to replace the existing 1000 lb GP (General Purpose) bomb. Initially using most of the components of the 1000 lb GP it was decided to give it a new tail and it was built with a half-inch-thick wall. Fillings could be Amatex, Amatol, Minol, RDX and others. Actual weight was around 1,020 lb (460 kg). [1] It was introduced to service in 1943 and about a quarter of a million were produced by the end of the war.
During the Korean War and Vietnam War the U.S. used older designs like the M65, M117 and M118, which had an explosive content about 65% higher than most contemporary weapons. Although some of these weapons remain in the U.S. arsenal, they are little used and the M117 is primarily carried only by the B-52 Stratofortress.
The primary U.S. GP bombs are the Mark 80 series. This class of weapons uses a shape known as Aero 1A, designed by Ed Heinemann of Douglas Aircraft as the result of studies in 1946. It has a length-to-diameter ratio of about 8:1, and results in minimal drag for the carrier aircraft. The Mark 80 series was not used in combat until the Vietnam War, but has since replaced most earlier GP weapons. It includes four basic weapon types:
Vietnam service showed the Mk 81 "Firecracker" to be insufficiently effective, and it was withdrawn from U.S. service. However, recently, precision-guided variants of the Mk 81 bomb have begun a return to service, based on U.S. experience in Iraq after 2003, and the desire to reduce collateral damage compared to Mk 82 and larger bombs (e.g., when attacking a single small building in a populated area).
Since the Vietnam War and the 1967 USS Forrestal fire, United States Navy and United States Marine Corps GP bombs are distinguished by a thick ablative fire-retardant coating, which is designed to delay any potential accidental explosion in the event of a shipboard fire. Land-based air forces typically do not use such coatings, largely because they add some 30 lb (14 kg) to the weight of the complete weapon.[ citation needed ] Fire is less a danger in a land-based facility, where the personnel can be evacuated with relative ease, and the building be the only loss. At sea, the crew and munitions share a facility (the ship), and thus are in much more danger of fire reaching munitions (which tend to be more closely packed, due to space limitations). Also, losing a munitions storage building on land is far cheaper than sacrificing an entire naval vessel, even if one could easily evacuate the crew.
All Mk 80 bombs have both nose and tail fuze wells and can accept a variety of fuzes. Various nose and tail kits can be fitted to adapt the weapon for a variety of roles.
In the Mk 80 series bomb bodies is also used in the following weapons:
On August 14, 2020, Kaman Precision Products received roughly $57.3 million for a "cockpit-selectable" bomb fuze to be used on Mark 80 warheads (guided and unguided). [2] The contract involved foreign military sales (FMS) to 25 unnamed countries.
Dumb Mk 80 bombs could be converted to smart bombs with attached kits:
The rearder is used to allow the aircraft escape the "blast pattern" in low altitude delivery. [9]
The principal modern British bombs are 540 lb (240 kg) and 1,000 lb (450 kg), and are no longer in service. The smaller 540 lb was retired with the demise of the Harrier GR9 aircraft with the larger 1000 lb being retired in Apr 2019. Currently the UK only uses the 500 lb class Paveway IV weapon system. The warhead is a modified enhanced Mk 82 warhead.
 | This section needs additional citations for verification .(January 2016) |
The Russian term for general-purpose bomb is fugasnaya aviatsionnaya bomba (FAB) and followed by the bomb's nominal weight in kilograms. Most Russian iron bombs have circular ring airfoils rather than the fins used by Western types.
In 1946 the Soviet Union developed a series of freefall bombs in four sizes 550 lb (250 kg), 1,100 lb (500 kg), 3,300 lb (1,500 kg), and 6,600 lb (3,000 kg) and sharing a single nose and a single tail fuze. The bomb could be dropped from up to 39,000 ft (12,000 m) and up to 620 mph (1,000 km/h). The original, 1946-series bombs had poor ballistic characteristics at supersonic speed, and their construction was fragile. As an interim measure, upgraded versions of the bombs were built with thicker walls and no nose fuze. The thick-walled version of the bombs was built until 1956.
The 1954 series of high-drag bombs was built in six sizes: 550 lb (250 kg), 1,100 lb (500 kg), 3,300 lb (1,500 kg), 6,600 lb (3,000 kg), 11,000 lb (5,000 kg), and 20,000 lb (9,000 kg). A feature of the 1954 series of bombs is the ballistic ring on the nose of the bomb which acts as a vortex generator to aid the bomb's stabilizers. [10] The smaller (less than 6,600 lb or 3,000 kg) bombs had a single nose and a single tail fuze, while the larger weapons shared a single nose fuze and two base fuzes. The FAB-9000 (20,000 lb or 9,000 kg) weapon was roughly comparable to the wartime Grand Slam bomb. It was used by Soviet aircraft designers as a substitute for early nuclear weapons when determining the size and clearances of bomb bays.
In 1962 a new series of streamlined, low-drag bombs was introduced, designed for external carriage by fighter-bomber aircraft rather than in internal bays. They come in only two sizes, 550 lb (250 kg) and 1,100 lb (500 kg). Both bombs have a single nose fuze.
Both the 54 and 62 series designs remain in use. The most common of these are the FAB-100, FAB-250, FAB-500, and FAB-1500, roughly corresponding to the U.S. Mark 80 series. These have seen widespread service in Russia, Warsaw Pact nations, and various export countries.
Larger bombs with less streamlined shapes also remained in the Soviet arsenal, primarily for use by heavy bombers. In the Iran–Iraq War, FAB-5000 (11,000 lb or 5,000 kg) and FAB-9000 (20,000 lb or 9,000 kg) bombs were dropped by Iraqi Air Force Tupolev Tu-22 bombers, generally against large, fixed targets in Iran. [11] In Afghanistan in the 1980s, Soviet Tupolev Tu-16 and Tupolev Tu-22M bombers used massive FAB-1500, FAB-3000, FAB-5000NG, and FAB-9000 bombs to devastating effect during the Panjshir offensives. More recently, many Russian FAB-500 and FAB-1500 general-purpose bombs were converted to precision munitions through the addition of mass-produced so-called UMPK kits, which add battery-powered electrically-actuated pop-out wings and flight control surfaces as well as guidance electronics, all of whose addition turns unguided gravity bombs into smart bombs with a glide ratio comparable to that of the Space Shuttle.
France produces or has produced numerous types of general-purpose bombs with weights ranging from 50 kg (110 lb) to 1,000 kg (2,200 lb), including US Mark 80 models.
Until 2011, bomb casings were made by the Société des Ateliers Mécaniques de Pont-sur-Sambre. The acronym “SAMP” identifies these bombs, along with various type codes such as EU2 and T200. [19] Since 2019, bomb casings are made at a new factory in Rouvignies and are filled with explosives at another factory in Sorgues. [20] [21]
India's Defence Research and Development Organisation (DRDO) has developed the High Speed Low Drag Bomb or HSLD series of general-purpose bombs. Size variations of these bombs are 100 kg (220 lb), 250 kg (550 lb), 450 kg (990 lb) and 500 kg (1,100 lb). The 450 kg and 500 kg bombs have precision-guided versions as well. The bombs are manufactured by Munitions India Limited.
Other countries, including Australia, [22] Azerbaijan, Brazil, Chile, Greece, [23] Israel, Pakistan, Poland, Portugal, Romania, South Africa, Spain, Sweden, and Turkey, manufacture their own bombs, most of which are either licensed versions of the U.S. Mark 80 series or close copies.
The KAB-500Kr is an electro-optical TV-guided fire and forget bomb developed by the Soviet Air Force in the 1980s. It remains in service with the CIS and various export customers.
The KAB-500L is a laser-guided bomb developed by the Soviet Air Force, entering service in 1975. It remains in service with the CIS and post-Soviet Russian Aerospace Forces.
The GBU-10 Paveway II is an American Paveway-series laser-guided bomb, based on the Mk 84 general-purpose bomb, but with laser seeking capabilities and wings for guidance. Introduced into service c. 1976, it is used today by USAF, US Navy, US Marine Corps, Royal Australian Air Force and various NATO air forces.
The GBU-12 Paveway II is an American aerial laser-guided bomb, based on the Mk 82 500-pound (227 kg) general-purpose bomb, but with the addition of a nose-mounted laser seeker and fins for guidance. A member of the Paveway series of weapons, Paveway II entered into service c. 1976. It is currently in service with the U.S. Air Force, U.S. Navy, U.S. Marine Corps, and various other air forces.
The GBU-28 is a 4,000-pound (1814.3 kg) class laser-guided "bunker busting" bomb produced originally by the Watervliet Arsenal, Watervliet, New York. It was designed, manufactured, and deployed in less than three weeks due to an urgent need during Operation Desert Storm to penetrate hardened Iraqi command centers located deep underground. Only two of the weapons were dropped in Desert Storm, both by F-111Fs. One GBU-28 was dropped during Operation Iraqi Freedom.
The Mark 84 or BLU-117 is a 2,000-pound (900 kg) American general-purpose bomb. It is the largest of the Mark 80 series of weapons. Entering service during the Vietnam War, it became a commonly used US heavy unguided bomb to be dropped. At the time, it was the third largest bomb by weight in the US inventory behind the 15,000-pound (6,800 kg) BLU-82 "Daisy Cutter" and the 3,000-pound (1,400 kg) M118 "demolition" bomb. It is currently sixth in size due to the addition of the 5,000 lb (2,300 kg) GBU-28 in 1991, the 22,600 lb (10,300 kg) GBU-43/B Massive Ordnance Air Blast bomb (MOAB) in 2003, and the 30,000 lb (14,000 kg) Massive Ordnance Penetrator.
The Mark 83 is a 1,000 pounds bomb, part of the Mark 80 series of low-drag general-purpose bombs in United States service.
GBU-24 Paveway III or simply GBU-24 is a family of laser-guided bombs, a sub-group of the larger Raytheon Paveway III family of weapons. The Paveway guidance package consists of a seeker package attached to the nose of the weapon, and a wing kit attached to the rear to provide stability and greater range.
The Mark 82 is a 500 pound unguided, low-drag general-purpose bomb, part of the United States Mark 80 series. The explosive filling is usually tritonal, though other compositions have sometimes been used.
The Joint Direct Attack Munition (JDAM) is a guidance kit that converts unguided bombs, or "dumb bombs", into all-weather precision-guided munitions. JDAM-equipped bombs are guided by an integrated inertial guidance system coupled to a Global Positioning System (GPS) receiver, giving them a published range of up to 15 nautical miles (28 km). JDAM-equipped bombs range from 500 to 2,000 pounds. The JDAM's guidance system was jointly developed by the United States Air Force and United States Navy, hence the "joint" in JDAM. When installed on a bomb, the JDAM kit is given a GBU identifier, superseding the Mark 80 or BLU nomenclature of the bomb to which it is attached.
Paveway is a series of laser-guided bombs (LGBs).
The Mark 81 is a general-purpose 250-pound (110 kg) bomb. It's the smallest of the Mark 80 series of low-drag general-purpose bombs.
The M118 is an air-dropped general-purpose or demolition bomb used by United States military forces. It dates back to the time of the Korean War of the early 1950s. Although it has a nominal weight of 3,000 pounds (1,400 kg), its actual weight, depending on fuse and retardation options, is somewhat higher. A typical non-retarded configuration has a total weight of 3,049 pounds (1,383 kg) with an explosive content of 1,975 pounds (896 kg) of tritonal. This is a higher percentage than in the more recent American Mark 80 series bombs thus the designation as a demolition bomb.
The "SPICE" is an Israeli-developed, EO/GPS- guidance kit used for converting air-droppable unguided bombs into precision-guided bombs.
A guided bomb is a precision-guided munition designed to achieve a smaller circular error probable (CEP).
The Sukhoi Su-30MKM is a twin-engine supermaneuverable fighter of the Royal Malaysian Air Force. It is a variant of the Su-30 series fighters, with many significant improvements over the original Su-30MK export version. The Su-30MKM was developed by the Sukhoi Design Bureau and is based on the Su-30MKI of the Indian Air Force. Both aircraft have common airframe, thrust vectoring engines and a digital fly-by-wire system, however the MKM version differs from the MKI mainly in the composition of the onboard avionics. It can carry up to 8,000 kg (17,637 lb) payload over a 1,296 km un-refueled combat radius.
LT PGB is an abbreviation for a family of Chinese built precision guided munitions named Fury Precision-guided munition Development NORINCO. Alternatively, LT PGB is also referred by its laser guidance, as Fury laser-guided bomb, or LT LGB.
A precision-guided munition is a guided munition intended to precisely hit a specific target, to minimize collateral damage and increase lethality against intended targets. During the First Gulf War guided munitions accounted for only 9% of weapons fired, but accounted for 75% of all successful hits. Despite guided weapons generally being used on more difficult targets, they were still 35 times more likely to destroy their targets per weapon dropped.
The FAB-500 is a Soviet-designed 500-kilogram (1,100 lb) general purpose air-dropped bomb with a high-explosive warhead, primarily used by the Russian Aerospace Forces, former Soviet republics and customer countries. The original M-54 model was rolled out in 1954, shaped for internal carriage by heavy bombers, a low-drag M-62 version in 1962 was intended for fighter bomber external hardpoint carriage. The bomb is unguided, features a single nose fuze, and is compatible with most models of Soviet aircraft.