GECAL 50 / GAU-19

Design work on the GECAL 50 began in 1982 at General Electric, which conceived the weapon as an enlarged counterpart to the M134 Minigun chambered for the .50 BMG cartridge. The loss of nine helicopters during the 1983 invasion of Grenada prompted General Electric to build prototypes in both three-barrel and six-barrel configurations, the latter intended for far higher cyclic rates. Production passed from General Electric to Lockheed Martin and subsequently to General Dynamics Ordnance and Tactical Systems, with the GAU-19A/B line later acquired by Fulcrum Concepts LLC.

The GAU-19/A is an externally powered, electrically driven rotary gun with three barrels; the six-barrel prototype configuration was not retained for production. It feeds standard NATO M9-linked .50 caliber ammunition, and the cyclic rate is selectable, with the Humvee armament kit fixed at an intermediate setting. Spin-up to maximum rate is brief. Ammunition capacity varies with the installation. The GAU-19/B, announced in January 2012, delivers the same output from a lighter mount optimised for a single firing rate. Both variants are rated to 40,000 mean rounds between failure.

The gun was proposed early on as armament for the V-22 Osprey, with a magazine beneath the cabin floor that could be reloaded in flight, but the installation was dropped. The US Navy issued a letter of qualification for GAU-19/A integration on naval aircraft in December 1992. In 2005 the type was approved for the OH-58D Kiowa, and it was also considered for the cancelled ARH-70. In 1999 the United States transferred 28 GAU-19s to Colombia, where they are used by drug enforcement troops and the Colombian National Police aboard AH-60L ARPIA III/IV helicopters and AC-47T gunships. The Mexican Navy and Air Force operate the system on MD-902 helicopters, UH-60 Black Hawks and Humvees, the latter also in Omani Army service. Further users include Czechia (12 GAU-19/B), Egypt, Iraq, Japan (Coast Guard, Kagayuki-class patrol craft), Saudi Arabia and Thailand (both on the AH-6i), Turkey, the United Arab Emirates (S-70M Black Hawks, Bell 407, naval vessels and Humvees) and the United States. Development of the GAU-19/B began in October 2010 following an urgent needs statement from the Armed Scout Helicopter Program Office; flight testing started in April 2011, the US Army ordered 30 units in January 2012 with delivery completed the following month, and the US Army Evaluation Center issued a safety confirmation for the OH-58D Kiowa Warrior in August 2012. Both variants have been fitted to naval vessels on tripods and remote weapon stations, to vehicles in turret and remotely operated mounts, and to rotary and fixed-wing aircraft as fixed forward underwing installations or door- and ramp-mounted guns. A self-contained gun pod was later developed by Fulcrum Concepts LLC.