F-35B BF-01 completes the first ever aircraft-mounted test-fire of the podded 25mm GAU-22/A cannon at Pax River. The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, all-weather stealth multirole fighters undergoing final development and testing by the United States. The fifth generation combat aircraft is designed to perform ground attack and air defense missions. The F-35 has three main models: the F-35A conventional takeoff and landing (CTOL) variant, the F-35B short take-off and vertical-landing (STOVL) variant, and the F-35C carrier-based Catapult Assisted Take-Off But Arrested Recovery (CATOBAR) variant.