Ground Launched Cruise Missile

BGM-109G Gryphon (GLCM)
BGM-109G Gryphon Transporter Erector Launcher (TEL) showing 4 missile launch tubes
Type	long-range, all-weather, subsonic tactical/strategic cruise missile
Service history
In service	1983–1991
Production history
Manufacturer	General Dynamics
Unit cost	$1.3 mil
Specifications
Weight	1,200 kilograms (2,600 lb)
Length	Without booster:5.56 metres (18.2 ft)
Diameter	0.52 metres (1.7 ft)
Engine	Williams International F107-WR-400 turbofan using TH-dimer fuel and a solid-fuel booster
Wingspan	2.67 metres (8.8 ft)
Operational range	2,500 kilometres (1,600 mi)
Speed	Subsonic—880 kilometres per hour (550 mph)
Guidance system	Inertial, TERCOM
Launch platform	Transporter erector launcher

The Ground Launched Cruise Missile, or GLCM, (officially designated BGM-109G Gryphon) was a ground-launched cruise missile developed by the United States Air Force in the last decade of the Cold War.

The BGM-109G was developed as a counter to the mobile medium- and intermediate- range ballistic nuclear missiles (SS-20 Saber) deployed by the Soviet Union in Eastern Bloc European countries. The GLCM and the U.S. Army's Pershing II may have been the incentives that fostered Soviet willingness to sign the Intermediate-Range Nuclear Forces Treaty (INF treaty), and thus possibly reduced the threat of nuclear wars in Europe. GLCM is also a generic term for any ground-launched cruise missile. Since the U.S. deployed only one modern cruise missile in the tactical role, the GLCM name stuck. The GLCM was built by General Dynamics.

A conventionally configured cruise missile, the BGM-109 was essentially a small, pilotless flying machine, powered by a turbofan engine. Unlike ballistic missiles, whose aimpoint is usually determined by gravitic trajectories, a cruise missile is capable of complicated aerial manoeuvres, and can fly a range of predetermined flight plans. Also, it flies at much lower altitudes than a ballistic missile, typically with a terrain-hugging flight plan. The trade-off for this low-observability flight is strike time; cruise missiles travel far more slowly than a ballistic weapon, and the GLCM was typical in this regard.

GLCM was developed as a ground-launched variant of the Tomahawk missile in use by the U.S. Navy (along with an undeveloped air-launched version, the Medium Range Air to Surface Missile [MRASM].) Unlike other variants of the Tomahawk, the GLCM carried only a W84 thermonuclear warhead ; no conventional capability was provided. The W84 warhead was a 0.2-150kt variable-yield weapon. This yield contrasts with the yield of the W80 warhead found on other versions of the Tomahawk and on the ALCM from which the W84 was derived, which had a selectable yield of 5 or 150 kt.The Pentagon credited the GLCM with a range of 2000–2500 kilometers. Like other U.S. cruise missiles of this period, accuracy after more than 2000 km of flight was within half the width of an American football field or 100 ft (approximately 30 meters). The missile was entirely subsonic, powered by a turbofan engine with a rocket booster assisting at launch.