CBU-87 Combined Effects Munition

The CBU-87 Combined Effects Munition (CEM) is a cluster bomb used by the United States Air Force, developed by Aerojet General/Honeywell and introduced in 1986 to replace the earlier cluster bombs used in the Vietnam War. CBU stands for Cluster Bomb Unit. When the CBU-87 is used in conjunction with the Wind Corrected Munitions Dispenser guidance tail kit, it becomes much more accurate, and is designated CBU-103.

The basic CBU-87 is designed to be dropped from an aircraft at any altitude and any air speed. It is a free-falling bomb and relies on the aircraft to aim it before it drops; once dropped it needs no further instruction, as opposed to guided munitions or smart bombs. The bomb can be dropped by a variety of modern-day aircraft. It is 7 ft long, has a diameter of 16 in, and weighs roughly 951 lb. The price is US$14,000 per bomb.

Each CBU-87 consists of an SUU-65B canister, a fuze with 12 time delay options and 202 submunitions (or bomblets) designated BLU-97/B Combined Effects Bomb. Each bomblet is a yellow cylinder with a length of 20 centimeters and a diameter of 6 centimeters. The BLU-97/B bomblets are designed to be used against armor, people and soft skinned targets and consist of a shaped charge, a scored steel fragmentation case and a zirconium ring for incendiary effects. The CBU-87 can also be equipped with an optional FZU-39/B proximity sensor with 10 altitude selections.

When dropped from an aircraft, the bomb starts spinning. There are 6 speeds that can adjust the bomb's rate of spin. After it drops to a certain altitude, the canister breaks open and the submunitions are released. Each bomblet has a ring of tabs at the tail end; these orient the bomblet and deploy an inflatable decelerator to decrease the falling speed of the bomblet. When the submunitions hit the ground, they will cover a large area and the CBU-87 can be adjusted so it can cover a smaller or wider area. Depending on the rate of spin and the altitude at which the canister opens, it can cover an area between 20×20 meters (low release altitude and a slow rate of spin) to 120×240 meters (high release altitude and a high rate of spin).

Manufacturers and the Department of Defense have claimed that each bomb's failure rate is about 5%. This equates to about 10 bomblets not exploding on impact of the 202 bomblets dropped. Landmine Action claimed the failure rate of the BLU-97/Bs used in the Kosovo campaign was higher, between 7 and 8 percent.

Operational use
During Operation Desert Storm, the US Air Force dropped 10,035 CBU-87s. During Operation Allied Force, the US dropped about 1,100 cluster bombs, mostly CBU-87s.

On 7 May 1999, a CBU-87 was used in one of the most serious incidents involving civilian deaths and cluster bombs, the Niš cluster bombing.