The picture shows a fighter F-35B with suspended under the fuselage gun installation GAU-22 / U.
Suspended installation armed 4-barrel 25 mm Gatling gun-type with a rate of 3300 rounds / min. This system has been specifically designed for F-35B by General Dynamics and has a much inflated fire accuracy than previous GAU-12 / U of the same caliber (5 ctvolnaya gun with a rate of 4200 rounds / min).
The fact that the F-35B unlike F-35A do not have sufficient interior volume to accommodate integrated guns. Unfortunately, this scheme reduces the stealth F-35B, the newspaper notes gizmodo.com. Photo was made June 14, 2012.
Mounted cannon installation GAU-22 / U 220 with ammunition shells is also designed to equip deck variant F-35C for the Navy. Integrated ammunition gun GAU-22 / A fighter F-35A — 182 projectile.