US Navy's Lockheed Martin F-35B stealth fighter has completed in-flight firing trials of its external under fuselage mounted 25 mm g...
US Navy's Lockheed Martin F-35B stealth fighter has completed in-flight firing trials of its external under fuselage mounted 25 mm gun.
The General Dynamics GAU-22/A gun is attached externally on a centerline station in a conformal pod and is intended to be used during close-range ground air support missions.
The final airborne gun fire testing took place on May 8, 2017 at the Naval Air Station (NAS) Patuxent river.
The removable or “missionized” externally mounted gun system will arm the US Marine Corps F-35B Short Takeoff and Vertical Landing and U.S. Navy's F-35C Carrier-Based aircraft variants, while U.S. Air Force F-35A Conventional Takeoff and Landing aircraft variant have an internally mounted gun system.
The four-barrel, externally powered Gatling gun weighs 735 pounds (334 kg) and can reach a fire rate of up to 3,300 shots per minute.
Derived from the 5-barrel 25 mm GAU-12/U gun used by U.S. Marine Corps AV-8B Harrier II aircraft, the GAU-22/A is over 40 pounds lighter and occupies 20 percent less volume than the GAU 12.
One of the major disadvantage of external gun mounting is the degraded low observable characteristics of the stealth fighter, while it also induce weight and drag penalty like an external store.
F-35's gun system has been controversial due to its delayed development period and limited fire power.
A big problem is that the gun system still cannot be aimed due to a delayed software development. The capability is slated to be released with the Block 3F software in 2019.
Also with its current fire rate, the 220 rounds ammo in external pod gun and 189 rounds in the internal version (F-35A) will be expended within 4 to 5 seconds, lasting for just 1 or 2 shots.
