 More advanced drones are made from large, older missiles which have had their warheads removed.In the United Kingdom, obsolete Royal Air Force and Royal Navy jet and propeller-powered aircraft (such as the Fairey Firefly, Gloster Meteor and de Havilland Sea Vixen used at RAE Llanbedr between the 1950s and 1990s) have also been modified into remote-controlled drones, but such modifications are costly.With a much larger budget, the U.S. military has been more likely to convert retired aircraft or older versions of still serving aircraft (e.g., QF-4 Phantom II and QF-16 Fighting Falcon) into remotely piloted targets for US Air Force, US Navy and US Marine Corps use as Full-Scale Aerial Targets.