The U.S. Army has a new version of the Hellfire II air-to-ground missiles, that can go after targets directly below, or behind, the aircraft firing it. This solves a particular problem with UAVs, because the vidcam on board can spot targets directly below, or even behind, the aircraft, while the Hellfire was designed to only go after targets in front of it. The new Hellfire accomplished all this with a multifunction guidance system. The new guidance system is also more accurate against moving targets.
The AGM-114 (Hellfire II) missiles use either an armor-piercing or blast/fragmentation (for use against non-armored targets and bunkers) warhead. The ones fired from UAVs usually have the blast warhead. The Hellfire II weighs 106 pounds, carries a 20 pound warhead and has a range of 8,000 meters. In addition to UAVs, the missile is most commonly used by the AH-64 helicopter gunship. An AH-64 can carry up to sixteen Hellfires at once. Predator, Reaper and Sky Warrior UAVs also use the Hellfire. The missile is popular for use in urban areas, because the small warhead (only a few pounds of explosives) reduces civilian casualties. The missile is accurate enough to be sent through a window (OK, you have to be really good, and lucky, to do this) because of its laser guidance. Hellfire is the most frequently used missile during the war on terror.