Notes Airbus Maveric EU UAV Experimental 2019 Prototype 1 [17][18] Boeing X-45 USA UAV Experimental 2002 Prototype 2 Boeing X-48 (C) USA UAV Experimental 2013 Prototype 2 Two engine Boeing X-48 (B) USA UAV Experimental 2007 Prototype 2 Three engine Lockheed A-12, M-21 and YF-12 US Jet Reconnaissance 1962 production 18 YF-12 was a prototype interceptor Lockheed SR-71 Blackbird US Jet Reconnaissance 1964 production 32 Northrop Grumman Bat US Prop/electric Reconnaissance 2006 production 10 McDonnell XP-67 USA Propeller Fighter 1944 Prototype 1 Aerofoil profile maintained throughout.