The F-35B Lightning II has achieved initial operating capability with the U.S. Marine Corps, which has authorized its worldwide deployment and use in combat. The short takeoff and vertical landing (STOVL) variant of the fifth-generation fighter is designed to transition in 15 seconds between forward flight and hover, according to developer Lockheed Martin. With STOVL, the F-35B can take off vertically with a light payload or launch from a short runway with a heavier payload. The Marines declared the initial capability July 31 for the first 10 F-35Bs in Marine Fighter Attack Squadron 121 (VMA-121), based in Yuma, Ariz. VMA-211 is scheduled to transition to the F-35B in fiscal year 2016. In 2018, VMA-311 will conduct its transition to the F-35B.