Perhaps the most widely used gun pod developed by the US military, fitted with a single GAU-2 7.62×51mm Minigun. This weapon was produced in three generations, with separate designations applied by both the US Army and US Air Force.
The first was the XM18 and SUU-11/A, which featured a standard version of the weapon encased in an aerodynamic pod. This weapon was unmodified and fired at a rate of 6,000 rpm. The fact that the weapon only fed from a drum containing 1,500 rounds of ammunition meant that a slower rate of fire was desired.
The second set of subvariants, designated XM18E1 (and standardized as the M18) and SUU-11A/A, featured an aircraft-to-pod electric connection, allowing aircraft internal power to be used in providing better starting torque, a de-energized solenoid allowing for better round clearing at low rates of fire, and circuitry that allowed for selectable rates of fire. The options were either 2,000 rpm or 4,000 rpm, both significantly lower than the base rate of fire.
The last set of subvariants were designated M18A1 (development of the M18E1) and SUU-11B/A. These featured a slightly higher set of selectable rates of fire, either 3,000 rpm or the high 6,000 rpm.
These pods were used on a wide array of US aircraft, primarily during the Vietnam War, including the A-1 Skyraider, A-37 Dragonfly, AC-47 Spooky, AC-119G Shadow, and the T-28 Trojan. It was also tested on the ACH-47A "Guns A-Go-Go" by the US Army and on the UH-1E Iroquois by the US Marine Corps, and were part of standard armament fits for the AH-1 Cobra with both services. List of U.S. aircraft gun pods - Wikipedia