AGM-86 ALCM

The AGM-86 ALCM (AGM-86A, AGM-86B, AGM-86C CALCM, AGM-86D CALCM) is an American subsonic air-launched cruise missile (ALCM) built by Boeing and operated by the United States Air Force. The missiles were developed to increase the effectiveness and survivability of Boeing B-52H Stratofortress bombers. In combination, they dilute an enemy's forces and complicate defense of its territory.

Examples of the Boeing AGM-86A and AGM-86B are on display at the Steven F. Udvar-Hazy Center of the National Air and Space Museum near Washington D.C.

Design
All variants of the AGM-86 missile are powered by a Williams F107 turbofan jet engine that propels it at sustained subsonic speeds and can be launched from aircraft at both high and low altitudes. The missile deploys its folded wings, tail surfaces and engine inlet after launch.

AGM-86B/C/D missiles increase flexibility in target selection. AGM-86B missiles can be air-launched in large numbers by the bomber force. B-52H bombers carry six AGM-86B or AGM-86C missiles on each of two externally mounted pylons and eight internally on a rotary launcher, giving the B-52H a maximum capacity of 20 missiles per aircraft.

An enemy force would have to counterattack each of the missiles, making defense against them costly and complicated. The enemy's defenses are further hampered by the missiles' small size and low-altitude flight capability, which makes them difficult to detect on radar.

AGM-86B
The nuclear armed AGM-86B uses a terrain contour-matching guidance system (TERCOM) to fly to its assigned target.

AGM-86C/D
The AGM-86C/D CALCM differs from the AGM-86B air-launched cruise missile in that it carries a conventional blast/fragmentation payload rather than a nuclear payload. The AGM-86C/D uses an onboard Global Positioning System (GPS) coupled with its inertial navigation system (INS) to navigate in flight. This allows the missile to guide itself to the target with pinpoint accuracy. Litton Guidance and Control, and Interstate Electronics Corp. were the guidance contractors for the C-model.

AGM-86A/B
In February 1974, the U.S. Air Force entered into contract to develop and flight-test the prototype or proof-of-concept vehicle AGM-86A air-launched cruise missile, which was slightly smaller than the later B and C models. The 86A model did not go into production; it was designed to fit the weapon bay of the B-1A, which was cancelled (to be later resurrected as the B-1B). Now being free of the length restriction of the B-1A weapon bay, the Air Force began full-scale development of the AGM-86B in January 1977, which greatly enhanced the B-52's capabilities and helped the USA maintain a strategic deterrent.

Production of the initial 225 AGM-86B missiles began in fiscal year 1980 and production of a total 1,715 missiles was completed in October 1986. The air-launched cruise missile had become operational four years earlier, in December 1982. More than 100 launches have taken place since then, with a 90% approximate success rate. The missile's flight path is pre-programmed and it becomes totally autonomous after launch.

In June 1986 a limited number of AGM-86B missiles were converted to carry a high-explosive blast/fragmentation warhead and an internal GPS. They were redesignated as the AGM-86C CALCM. This modification also replaced the B model's terrain contour-matching guidance system (TERCOM) and integrated a GPS capability with the existing inertial navigation computer system.

AGM-86C/D
The AGM-86C is a Conventional Air-Launched Cruise Missile (CALCM) and is a conventional blast/fragmentation derivative of the nuclear armed AGM-86B. The AGM-86D is the Penetrator version of the CALCM which is designed to attack deeply buried targets.

In 1996 and 1997, 200 additional CALCMs were produced from excess ALCMs. These missiles, designated Block I, incorporate improvements such as a larger and improved conventional payload (3,000 pound blast class), a multi-channel GPS receiver and integration of the buffer box into the GPS receiver. The upgraded avionics package was retrofitted into all existing CALCM (Block 0) so all AGM-86C missiles are electronically identical.

Operations
The CALCM became operational in January 1991 at the onset of Operation Desert Storm. Seven B-52Gs from Barksdale AFB launched 35 missiles at designated launch points in the U.S. Central Command's area of responsibility to attack high-priority targets in Iraq. These "round-robin" missions marked the beginning of the operation's Air Force component and are the longest known aircraft combat sorties in history (more than 14,000 miles and 35 hours of flight).

CALCM's next employment occurred in September 1996 during Operation Desert Strike. In response to Iraq's continued hostilities against the Kurds in northern Iraq, the Air Force launched 13 CALCMs in a joint attack with the Navy. This mission has put the CALCM program in the spotlight for future modifications. Operation Desert Strike was also the combat debut of the B-52H and the carriage of the CALCM on the weapons bay-mounted Common Strategic Rotary Launcher (CSRL). During the Operation Desert Storm, the CALCM had been carried on the B-52G and wing-mounted pylons.

The CALCM was also used in Operation Desert Fox in 1998, Operation Allied Force in 1999, and Operation Iraqi Freedom in 2003. Operation Iraqi Freedom was also the combat debut of the AGM-86D, a further development of the missile which replaced the blast/fragmentation warhead of the AGM-86C with a penetrating warhead.

Future of the ALCM
The Air Force in 2008 maintains an arsenal of 1,140 AGM-86 Air Launched Cruise Missiles and 460 newer and stealthy AGM-129 ACM (Advanced Cruise Missiles). The B-52 Stratofortress is the only delivery bomber for these missiles.

In 2007, the USAF announced its intention to retire all of its AGM-129 ACMs, and to reduce the ALCM fleet by more than 500 missiles, leaving 528 nuclear cruise missiles. The ALCM force will be consolidated at Minot Air Force Base, North Dakota, and all excess cruise missile bodies will be destroyed.

The reductions are in part a result of the Strategic Offensive Reductions Treaty requirement to go below 2,200 deployed nuclear weapons by 2012, with the AGM-129 ACM chosen because it has reliability problems and also higher maintenance costs.

Even with the SLEP, the remaining AGM-86s will reach their end of service by 2020, leaving the B-52 without a nuclear mission. However in 2012, the USAF announced plans to extend the useful life of the missiles until at least 2030.

The USAF plans to award a contract for the development of the replacement Long-Range Stand-Off (LRSO) weapon in 2015. The technology development contracts are to be submitted before the end of 2012.