The first F-35B test flight with external weapons was carried out on 22 February 2012 at the Naval Air Warfare Center Aircraft Division test facility at NAS Patuxent River Maryland. The test mission, flown by Lockheed Martin test pilot Dan Levin, measured flying qualities with external pylons, inert AIM-9X Sidewinder air-to-air missiles, and the removable centerline 25mm gun pod. The four-barrel GAU-22/A Gatlin-type gun, built by General Dynamics Armament and Technical Products, is a derivative of the currently fielded GAU-12/U Equalizer. The missionized gun system designed for the F-35B and F-35C includes the F-35A-common GAU-22/A gun, a gun system control unit, and drive assembly. A helical linear linkless ammunition feed system is also contained in the pod.
