Mandatory Credit: Photo by REX/Shutterstock (8659953a) An F-35B Lightning II with Marine Fighter Attack Squadron (VMFA) 121, lands at Marine Corps Air Station Iwakuni, Japan, Jan. 18, 2017. VMFA-121 conducted a permanent change of station to MCAS Iwakuni, from MCAS Yuma, Ariz., and now belongs to Marine Aircraft Group 12, 1st Marine Aircraft Wing, III Marine Expeditionary Force. The F-35B Lightning II is a fifth-generation fighter, which is the world's first operational supersonic short takeoff and vertical landing aircraft. The F-35B brings strategic agility, operational flexibility and tactical supremacy to III MEF with a mission radius greater than that of the F/A-18 Hornet and AV-8B Harrier II in support of the U.S. ? Japan alliance. US military operations