CBU-97 Sensor Fuzed Weapon

Model of the SFW displayed at the Textron Defense Systems booth, Singapore Airshow 2008

Developed and produced by Textron Defense Systems, the CBU-97 Sensor Fuzed Weapon is a United States Air Force 1,000-pound-class (450 kg) non-guided (freefall) cluster bomb, hence the name CBU (Cluster Bomb Unit).

Overview

The CBU-97 consists of an SUU-66/B tactical munition dispenser that contains 10 BLU-108 submunitions. Each submunition contains four hockey-puck-shaped sensor-fused projectiles called Skeets. These detect targets, such as tanks, armored personnel carriers, trucks and other support vehicles, and fire an explosively formed penetrator.

Operation

The 40 Skeets scan an area of 1,500 feet by 500 feet (460 m × 150 m) using infrared and laser sensors until it finds a target, or failing that, self-destructs 50 feet (15 m) above the ground. This harasses dismounted troops and prevents any rounds that do not explode immediately from hurting civilians later. There is also a back-up timer that enables the Skeet to time-out seconds after hitting the ground. These two redundant self-destruct modes results in an unexploded-ordnance rate of less than 1%.

As the CBU-97 approaches its designated aim-point, the dispenser skin is severed into three panels by an explosive cutting charge. The slipstream peels away these panels, exposing the 10 BLU-108 submunitions. An airbag ejects the forward five submunitions, then five in the aft bay. Following a preset timeline, the submunitions deploy parachutes so that they are spaced about 100 feet (30 m) apart. Then each submunition releases its chute, fires a rocket motor that stops its descent and spins it on its longitudinal axis, and releases pairs of Skeets 90 degrees apart. Each spinning Skeet makes a coning motion that allows it to scan a circular area on the ground.

The laser sensor detects changes in height such as the distinctive contour of a vehicle. At the same time, infrared sensors detect heat signatures, such as those emitted by the engine of a target vehicle. When the combination of height contours and heat signatures indicative of a target are detected, the Skeet detonates, firing an explosively formed penetrator (EFP) into the target vehicle at high speed, enabling it to penetrate armor plating and destroy what is underneath the armor plating. Note that SFW disables targets using the kinetic energy of the EFP, not the blast of an explosive charge.

The weapon is deployed by US Air Force tactical aircraft from altitudes of 200 feet (60 m) Above Ground Level (AGL) to 20,000 feet (6100 m) Mean Sea Level (MSL) at speeds of 250 to 650 knots.

The CBU-97 was first deployed during Operation Allied Force when the United States and NATO entered the Kosovo War, but were not used. Sensor-fused weapons were first fired in combat during the 2003 invasion of Iraq.

When the CBU-97 is used in conjunction with the Wind Corrected Munitions Dispenser guidance tail kit, it is designated as CBU-105.

The Pentagon has notified the US Congress of its offer to sell India CBU-105 Sensor Fuzed Weapons (SFW)

General characteristics

• Type: Freefall bomb
• Weight: 927lbs (420 kg)
• Name: CBU-97 Sensor Fused Weapon (SFW)
• Length: 92 inches (234 cm)
• Diameter: 15.6 inches (40 cm)
• Dispenser: SW-65 tactical dispenser
• Bomblets: 10 × BLU-108/B
• Warhead: Armour Piercing
• Unit Cost: $360,000 - baseline

External links

• Sensor Fuzed Weapon (SFW) - Textron Defense Systems
• Federation of American Scientists article about SFW's
• GlobalSecurity.org: CBU-97 Sensor Fuzed Weapon
• GlobalSecurity.org: CBU-105 Wind Corrected Munition Dispenser (WCMD)
• GlobalSecurity.org: BLU-108/B Submunition
• Animated Video of SFW Deployment