Defense Technology International - September 2007 - (Page 56) WEAPONS PRECISION U.S. AIR FORCE Inert bombs are an option for destroying targets in densely populated areas. howitzer shells fired by AC-130 gunships. These also have carbonfiber casings and DIME charges. They are for use on precise-point targets, allowing gunships to destroy a vehicle or weapon but leave nearby objects intact. For multi-story structures in urban areas, the Hardened Surface Target Ordnance Package, or HardSTOP an AFRL weapon, neutralizes tar, gets in buildings without collateral damage. In a scenario where enemy leaders meet on, say, the top floor of a four-story residential building, a 2,000-lb. bomb might have been used to destroy the structure, to the detriment of civilians and adjacent buildings. HardSTOP utilizes a munitions dispenser filled with 54 penetrating charges in two sizes. Seconds before impact the penetrators are released in a preset pattern 20-100 ft. in diameter. INS/GPS components assure precise impact. “The large penetrators can penetrate through more levels of the target than the small [ones],” says Ken West, AFRL Munitions Directorate engineer. “By using two different sizes, you get the optimum combination of penetration capability and pattern density, such that you can saturate the entire structure.” Each penetrator has a programmable fuze and a small explosive. Electronic time delay allows a penetrator to attack a specific floor. Fuzes can be set to detonate on every floor or to explode on only one level. “Each fuze has a slightly different detonation time, which produces a different blast effect,” says West. “This, [and] the fact that the detonations are distributed throughout the structure, greatly reduces the potential for major damage within and beyond the target.” HardSTOP is similar externally to existing munitions dispensers, and is compatible with launch systems. Perhaps its biggest hurdle is public relations: It may be perceived as a cluster bomb and deemed unacceptable by some policy-makers. AFRL CONCEPT Tactical Munitions Dispenser INS/GPS Aided guidance Mini-Penetrators with HE Warheads 2 sizes Multi-story target interior saturated with small explosive charges Selectable pattern size HardSTOP’s penetrating charges are preset to explode at various times in patterns to minimize destruction. 56 DEFENSE TECHNOLOGY INTERNATIONAL SEPTEMBER 2007 The simplest way of reducing collateral damage is to remove explosives altogether. The weapon then relies on kinetic energy for destruction, becoming in effect a giant cannonball. This technique was pioneered in Iraq by Lt. Gen. David Deptula, then a USAF colonel and commander of Operation Northern Watch, which enforced the no-fly zone in Iraq. In 1998, mobile Iraqi surface-to-air missile launchers were increasingly located near schools, mosques and residential areas to deter attacks against them. Deptula ordered the use of inert laser-guided practice bombs on such targets. The bombs made direct—and devastating—hits. Deptula has described the effect of the impact as akin to “500 lb. of concrete going 500 kt. [that] will ruin your day.” Inert 500- and 2,000lb. bombs have been effective against lightly armored vehicles without damaging nearby buildings. The CBU-107 Passive Attack Weapon (PAW), manufactured by General Dynamics, Lockheed Martin and Textron Systems, extends the kinetic approach to a wide-area target. The precisionguided weapon is loaded with 3,750 tungsten and steel flechettes 2-14 in. long. The mixture of sizes balances penetration and coverage, producing a “hurricane of metal” within a 200-ft. area. The largest darts weigh 1.5 lb. PAW is for use where there is a need to pinpoint targets. In the weapon’s first mission, during Operation Iraqi Freedom, two were employed to destroy only the antennae on Iraq’s information ministry building. The main targets, though, are stockpiles of fuel or chemical and HardSTOP canister biological weapons (CBW). The releases projectiles flechettes puncture metal drums. prior to impact. This weapon is a safer option than explosives, which could spread the contents over a wide area. After PAW releases CBW agents from containers, they can be neutralized with incendiaries. One flexible small munition, the GBU-44 Viper Strike, a 40-lb. glide bomb with a 2-lb. warhead, was developed by Northrop Grumman as an offshoot of its Brilliant Anti-Tank weapon. It is designed for soft targets. Released from a UAV at 10,000 ft., Viper Strike is laser guided and, with a circular error probable of just 3 ft., can hit a target moving at 25 mph. or a specific window in a building. The attack profile is nearly vertical, so shrapnel from the shaped-charge warhead tends to go straight into the ground, limiting the damage radius to about 50 ft. “We can drop this between a mosque and a busload of nuns and not hurt [either],” says a deputy product manager for Viper Strike. A further development will give Viper Strike a less lethal mode due to an inert warhead. The kinetic energy of the weapon provides enough punch to put a vehicle’s engine out of action—supposedly without harming the occupants. The weapon is being developed for Special Operations Command and the U.S. Army. Efforts to limit collateral damage increasingly mean that some target opportunities may have to be abandoned or at least deferred because the risk of incidental casualties and destruction is too high. “If we cannot neutralize our enemy today without harming civilians, our enemy will give us the opportunity tomorrow,” de Hoop Scheffer told the Financial Times. “If that means going after a Taliban not on Wednesday but on Thursday, we will get him then.” I AFRL www.aviationweek.com/dti http://www.aviationweek.com/dti
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