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Cluster Bombs

US Air Dispensed Submunitions

Weapon Submunition Submunition

Regardless of its type or purpose, dropped ordnance is dispensed or dropped from an aircraft. Dropped ordnance is divided into three subgroups: bombs; dispensers, which contain submunitions; and submunitions.


Dispensers may be classified as another type of dropped ordnance. Like bombs, they are carried by aircraft. Their payload, however, is smaller ordnance called submunitions. Dispensers come in a variety of shapes and sizes depending on the payload inside. Some dispensers are reusable, and some are one-time-use items.

Dropped dispensers fall away from the aircraft and are stabilized in flight by fin assemblies. Dropped dispensers may be in one piece or in multiple pieces. All dropped dispensers use either mechanical time or proximity fuzing. These fuzes allow the payload to be dispersed at a predetermined height above the target. Multiple-piece dispensers open up and disperse their payload when the fuze functions. Single-piece dispensers eject their payload out of ports or holes in the body when the fuze functions.

Attached dispensers stay attached to the aircraft and can be reloaded and used again. Their payload is dispersed out the rear or from the bottom of the dispenser.


Submunitions are classified as either bomblets, grenades, or mines. They are small explosive-filled or chemical-filled items designed for saturation coverage of a large area. They may be antipersonnel (APERS), antimateriel (AMAT), antitank (AT), dual-purpose (DP), incendiary, or chemical. Submunitions may be spread by dispensers, missiles, rockets, or projectiles. Each of these delivery systems disperses its payload of submunitions while still in flight, and the submunitions drop over the target. On the battlefield, submunitions are widely used in both offensive and defensive missions.

Submunitions are used to destroy an enemy in place (impact) or to slow or prevent enemy movement away from or through an area (area denial). Impact submunitions go off when they hit the ground. Area-denial submunitions, including FASCAM, have a limited active life and self-destruct after their active life has expired. The major difference between scatterable mines and placed mines is that the scatterable mines land on the surface and can be seen. Placed mines may be hidden or buried under the ground and usually cannot be seen.

The ball-type submunitions are APERS. They are very small and are delivered on known concentrations of enemy personnel, scattered across an area. Like a land mine, it will not blow up until pressure is put on it.

The APERS submunition can be delivered by aircraft or by artillery. When it hits the ground, a small fragmentation ball shoots up and detonates about 6 feet above the ground. The area-denial APERS submunitions (FASCAM) are delivered into areas for use as mines. When they hit the ground, trip wires kick out up to 20 feet from the mine. All area-denial submunitions use antidisturbance fuzing with self-destruct fuzing as a backup. The self-destruct time can vary from a couple of hours to as long as several days.

The AMAT and/or AT submunitions are designed to destroy hard targets such as vehicles and equipment. They are dispersed from an aircraft-dropped dispenser and function when they hit a target or the ground. Drogue parachutes stabilize these submunitions in flight so they hit their targets straight on. The submunitions are also used to destroy hard targets such as vehicles and equipment. The only difference is that the fin assembly stabilizes the submunition instead of the drogue parachute.

AT area-denial submunitions can be delivered by aircraft, artillery, and even some engineer vehicles. These FASCAMs all have magnetic fuzing. They will function when they receive a signal from metallic objects. These submunitions, similar to the APERS area-denial submunitions, also have antidisturbance and self-destruct fuzing. AT and APERS area-denial mines are usually found deployed together.

Most airframes are capable of delivering a variety of submunitions. There is no set air delivery mission profile. The hazard area depends on the submunition, mission profile, target type, and number of sorties. Air Force and naval air power employ cluster bomb units (CBUs) containing submunitions that produce hazard areas similar to MLRS/ cannon artillery submunitions. Air delivered canisters contain varying amounts of CBUs. One CBU-58 or three CBU-87/ CBU-52 contain approximately the same number of submunitions as one MLRS rocket with 644 submunitions. A B-52 dropping a full load of 45 CBUs (each CBU-58/CBU-71 contains 650 submunitions) may produce an hazard area that is significantly more dense than an MLRS hazard area. A typical F-16 flying close air support (CAS) against a point target may drop two CBUs per aircraft per run, thus producing a very low-density hazard area.

Saturation of unexploded submunitions has become a characteristic of the modern battlefield. The potential for fratricide from unexploded ordnance [UXO] is increasing. Joint Publication 1-02 defines unexploded explosive ordnance as “explosive ordnance which has been primed, fused, or otherwise prepared for action, and which has been fired, dropped, launched, projected, or placed in such a manner as to constitute a hazard to operations, installations, personnel or material and remains unexploded either by malfunction or design or for any other cause." Although ground forces are concerned with all unexploded ordnance, the greatest potential for fratricide comes from unexploded submunitions.

Submunition function reliability requirement is no less than 95 percent. With a 95 percent submunition function reliability, one CBU-58 (with 650 submunitions) could produce up to 38 unexploded submunitions. A typical B-52 dropping a full load of 45 CBU-58/CBU-71, each containing 650 submunitions, could produce an average of some 1700 unexploded sub-munitions. The numbers of submunitions that fail to properly function and the submunitions’ dispersion determine the actual density of the hazard area.

Studies that show 40 percent of the duds on the ground are hazardous and for each encounter with an unexploded submunition there is a 13 percent probability of detonation. Thus, even though an unexploded submunition is run over, kicked, stepped on, or otherwise disturbed, and did not detonate, it is not safe. Handling the unexploded submunition may eventually result in arming and subsequent detonation.

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Originally Updated Saturday, June 26, 1999 4:21:40 PM