Phalanx close-in weapons system
A final anti-air warfare defense against sea-skimming anti-shipping missiles in the performance range of the AGM-84 Harpoon and French Exocet, the Phalanx close-in weapons system is an autocannon firing depleted uranium 20mm shells. The kinetic energy of the massive shells is intended not just to destroy, but to deflect the incoming missile.
It is not long-ranged enough to deal with supersonic threats such as the Russian Moskit series (NATO: SS-N-22 SUNBURN, and the RIM-116 Rolling Airframe Missile is being introduced as the final defense against such missiles. British Goalkeeper 30mm and 35mm Oerlikon Skyguard and Oerlikon Millenium have similar functions and limitations.
The Phalanx is fast enough to engage and defeat unguided rockets such as the Russian GRAD series, the descendant of the World War II Katyusha rockets. Phalanx systems have shot down rockets, and possibly mortar shells, aimed at U.S. bases in Iraq and Afghanistan.
System control
The original version, placed in automatic mode, uses radar to locate and engage incoming missiles, tracking both the missiles and its own stream of fire, to bring them into collision. It had been left in standby mode when Iraqi Exocet missiles struck the USS Stark.
Block 1B's adds man-in-the-loop system control, as well as a forward-looking infrared (FLIR) tracker to complement the radar. Block 1B can engage littoral threats including small, high-speed boats, small terrorist aircraft, helicopters and surface mines. This new version also incorporates new Optimized Gun Barrels which provide improved barrel life, decreased round dispersion and increased engagement ranges.
Deployment
Phalanx production started in 1978 and was first deployed in 1980 on the USS Coral Sea (CV 43). It has been sold to 14 nations.
Presumably operated by U.S. Army air defense artillery personnel, they are being used in the counter rocket, artillery and mortar (C-RAM) in Iraq and Afghanistan. There have been reports that Israel is interested in Phalanx or a similar system for protecting against rocket attack on cities, until a laser system in development is operational.