The General Dynamics GAU-12/U Equalizer is a five-barrel 25 mm Gatling-type rotary cannon . The GAU-12/U is used by the United States, Italy and Spain, which mount the weapon in their attack jets such as the AV-8B Harrier II , airborne gunships such as the Lockheed AC-130 , and land-based fighting vehicles. A lighter four-barrel version, designated GAU-22/A , is mounted on F-35 Lightning II fighter jets.
17-444: The five-barrel Equalizer cannon was developed in the late 1970s, based on the mechanism of the 30mm GAU-8/A Avenger cannon, but firing a new NATO series of 25 mm ammunition. The GAU-12/U cannon is operated by an 11 kW (15 hp) electric motor , or in external mounts supplied by a bleed air driven pneumatic system. Its rate of fire is normally 3,600 rounds per minute, with a maximum of 4,200 rounds per minute. For use in
34-418: A Close-In Weapon System , as the gun was not automatic nor did it use radar tracking. Instead the gun was manually aimed using a digital gun sight and fire control. Sea Vulcan consisted of a 540-round helical drum magazine, a one-piece aluminum turret that can be opened with just a screwdriver, and the main gun. One unique advantage of the system was that it was capable of operating independently of ship's power;
51-417: A variety of measuring devices, and each different pressure is a different set point for a valve. A typical standard signal is 20–100 kPa. For example, a valve could be controlling the pressure in a vessel that has a constant out-flow, and a varied in-flow (varied by the actuator and valve). A pressure transmitter will monitor the pressure in the vessel and transmit a signal from 20–100 kPa. 20 kPa means there
68-639: Is also used in the AC-130U Spooky gunship , where one cannon is mounted on the port side, and the U.S. Marine Corps LAV-AD air-defense vehicle. Other applications have been planned for the GAU-12/U, including a mounting for the AH-1 Cobra attack helicopter . The Equalizer was also used as the basis for the Sea Vulcan 25 , a turret mounted gun for naval ship self-defense, although not as
85-418: Is no pressure, 100 kPa means there is full range pressure (can be varied by the transmitters calibration points). As the pressure rises in the vessel, the output of the transmitter rises, this increase in pressure is sent to the valve, which causes the valve to stroke downward, and start closing the valve, decreasing flow into the vessel, reducing the pressure in the vessel as excess pressure is evacuated through
102-553: The AC-130 gunship, the fire rate is limited to 1,800 rounds per minute in order to conserve ammunition and reduce barrel wear. The GAU-22/A is a four-barrel version of the GAU-12/U designed for use on the F-35 Lightning II . The GAU-22/A's major difference is the use of four barrels, rather than the GAU-12/U's five barrels. The GAU-22/A is lighter and has a reduced rate of fire of 3,300 rounds per minute, but maintains
119-463: The magazine , weighs 900 lb (410 kg) empty and 1,230 lb (560 kg) loaded. The detachable pods are located and shaped to be interchangeable with the usual ventral strakes or fences under the Harrier, both serving to help trap a cushion of high-pressure air under the aircraft to add lift while in hover mode. The strakes can easily be removed and the pods attached in their place, serving
136-425: The valve stem to fail. This pressure is transferred to the valve stem, which is connected to either the valve plug (see plug valve ), butterfly valve etc. Larger forces are required in high pressure or high flow pipelines to allow the valve to overcome these forces, and allow it to move the valves moving parts to control the material flowing inside. The valve's input is the "control signal." This can come from
153-536: The Wikimedia System Administrators, please include the details below. Request from 172.68.168.133 via cp1102 cp1102, Varnish XID 572106660 Upstream caches: cp1102 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 07:45:10 GMT Pneumatic actuator A pneumatic control valve actuator converts energy (typically in the form of compressed air ) into mechanical motion. The motion can be rotary or linear , depending on
170-433: The fuselage underside, with the cannon in the port pod and 300 rounds of ammunition in the starboard pod, fed through a bridge at the aft ends of the pods that also contains the drive system for the gun (unlike previous Harriers which used dual cannons, with each pod containing a 30mm ADEN gun and its own ammunition supply). The complete installation, which includes a double-ended feed system that returns empty cartridges to
187-582: The gun and ammunition magazine were powered by a 3,000 psi (21 MPa) pneumatic drive and the turret motor by twin lead–acid batteries . Intended as a higher-firepower alternative to conventional deck-mounted machine guns and cannon, the weapon employs the Navy's Mk 24 target designator and laser range finder for enhanced accuracy. The gun was developed in the mid-1980s as a cost-effective protection for ships smaller than frigate or corvette or patrol boats, but did not enter this service. The GAU-12
SECTION 10
#1732779910017204-435: The piston, the larger the output pressure can be. Having a larger piston can also be good if the air supply is low, allowing the same forces with less input. These pressures are large enough to crush objects in the pipe. On 100 kPa input, you could lift a small car (upwards of 1,000 lbs) easily, and this is only a basic, small pneumatic valve. However, the resulting forces required of the stem would be too great and cause
221-611: The presence of a clockworking inertia-driven mechanical fuze in the mid-body, protects the round from shocks, misfires and cookoffs, making it safer to handle and fire. The current principal application for the Equalizer is the AV-8 Harrier IIs of the United States Marine Corps , Italian Navy and Spanish Navy . The Harrier II carries the Equalizer system in a pair of detachable pods mounted on
238-453: The same function while adding useful firepower. RAF and Fleet Air Arm Harriers did not adopt the Equalizer for their Harrier GR7 and GR9s. The British had originally planned a pair of ADEN 25 guns (using the same ammunition as the GAU-12/U, but based on the 30 mm ADEN cannon ). That gun was canceled in 1999 after protracted development problems, and British Harrier GR7/9s were without gun armament until retirement. The Equalizer
255-549: The same, high accuracy of 5 milliradians , 80% circle of the GAU-12 and A-10's GAU-8. The weapon is produced by General Dynamics Ordnance and Tactical Systems. The Nammo 25 mm PGU-47/U APEX (Armor Piercing with Explosive) projectile has been developed for the GAU-22/A. It features a tungsten carbide penetrator in the tip and an explosive fragmentation body, to be multi-purpose against both hardened and soft targets. Also,
272-408: The type of actuator. A pneumatic actuator mainly consists of a piston or a diaphragm which develops the motive power. It keeps the air in the upper portion of the cylinder, allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element. Valves require little pressure to operate and usually double or triple the input force. The larger the size of
289-759: Was utilized as the principal armament for the Rutan ARES . The four-barrel GAU-22 is carried internally by the F-35A (the CTOL version of the F-35) on the port side of the fuselage, with 181 PGU-47/U APEX rounds. In contrast, the F-35B STOVL and C CATOBAR aircraft mount the GAU-22 in a stealthy external gun pod under the fuselage, together with 220 rounds. GAU-8 Too Many Requests If you report this error to
#16983