F-35 test pilots Marine Corps Maj. C. R. Clift and Navy Lt. Cmdr. Michael Burks fly two F-35B flight test aircraft (designated BF-2 and BF-4) during the first formation flying qualities test of the short takeoff/vertical landing variant of the F-35 over the Atlantic Test Range on 22 August 2012. The F-35B is one of the two F-35 variants that will be flown by US Marine Corps. The United Kingdom and Italy will also fly the F-35B.