The X-planes are a series of experimental United Statesaircraft and rockets, used to test and evaluate new technologies and aerodynamic concepts. They have an X designator within the US system of aircraft designations, which denotes the experimental research mission.
Not all US experimental aircraft have been designated as X-planes; some received US Navy designations before 1962,[1] while others have been known only by manufacturers' designations,[N 1] non-'X'-series designations,[N 2] or classified codenames.[N 3] This list only includes the designated X-planes.
The first experimental aircraft specification, for a transonic rocket plane, was placed in 1945, and the first operational flight of an X-plane took place when the Bell X-1 made its first powered flight nearly three years later at Muroc Air Force Base, California, now known as Edwards Air Force Base.[3] The majority of X-plane testing has since taken place there.[4]
X-planes have since accomplished many aviation "firsts" including breaking speed and altitude barriers, varying wing sweep in flight, implementing exotic alloys and propulsion innovations, and many more.[2]
New X-planes appeared fairly regularly for many years until the flow temporarily stopped in the early 1970s. A series of experimental hypersonic projects, including an advanced version of the Martin Marietta X-24lifting body, were turned down. Eventually issues with the Rockwell HiMAT advanced UAV led to a crewed X-plane with forward sweep, the Grumman X-29, which flew in 1984.[5]
Some of the X-planes have been well publicized, while others, such as the X-16, have been developed in secrecy.[6] The first, the Bell X-1, became well known in 1947 after it became the first aircraft to break the sound barrier in level flight.[7] Later X-planes supported important research in a multitude of aerodynamic and technical fields, but only the North American X-15rocket plane of the early 1960s achieved comparable fame to that of the X-1.[citation needed] X-planes 8, 9, 11, 12, and 17 were actually missiles[8] used to test new types of engines, and some other vehicles were unoccupied or UAVs (some were remotely flown, some were partially or fully autonomous).
^ a bHarrington, J.D.; Kamlet, Matt; Barnstorff, Kathy (17 June 2016). "NASA Hybrid Electric Research Plane Gets X Number, New Name". NASA.gov. NASA. Retrieved 17 June 2016.
^The Air Force Valkyrie Drone, a Sidekick for Human-Piloted Planes, Will Fly This Year
^Jim, Banke (27 June 2018). "NASA's Experimental Supersonic Aircraft Now Known as X-59 QueSST". NASA. Retrieved 28 June 2018.
^"U.S. Air Force Designates GO1 Hypersonic Flight Research Vehicle as X-60A". generationorbit.com. 4 October 2018. Retrieved 4 October 2018.
^"Earthquake damage delays Gremlins trial". Flight International. 24 September 2019. Retrieved 28 October 2019.
^"Dynetics X-61A Gremlins makes first flight, but destroyed after parachute fails". Flight International. 17 January 2020. Retrieved 13 February 2020.
^Giancarlo Casem (30 Jul 2021) NF-16D VISTA becomes X-62A, paves way for Skyborg autonomous flight tests
^ a b"AFRL's Rocket Lab Past, Present and Future". AFRL. Retrieved 25 August 2024.
^"ABL Space Systems' rocket fails on maiden launch". Reuters. 11 January 2023. Archived from the original on 11 January 2023. Retrieved 11 January 2023.
^Hadley, Greg (16 May 2023). "Meet the X-65: DARPA's New Plane Has No External Control Surfaces". Air & Space Forces Magazine. Retrieved 29 May 2023.
^O’Shea, Claire (12 June 2023). "Next Generation Experimental Aircraft Becomes NASA's Newest X-Plane". NASA. Retrieved 13 June 2023.
Bibliography
Jenkins, Dennis R.; Landis, Tony; Miller, Jay (June 2003). American X-Vehicles: An Inventory—X-1 to X-50 (PDF). Monographs in Aerospace History. Vol. 31 (Centennial of Flight ed.). Washington, DC: NASA History Office. SP-2003-4531. Retrieved 22 January 2024.
Jordan, Holly (2006). "Active Aeroelastic Wing flight research vehicle receives X-53 designation". Wright-Patterson Air Force Base. Archived from the original on 5 June 2011. Retrieved 11 May 2010.
Kaufman, Derek (2009). "Advanced Composite Cargo Aircraft gets X-plane designation". United States Air Force. Retrieved 11 May 2010.
Miller, Jay (1985). The X-Planes: X-1 to X-45 (first UK ed.). Midland Counties. ISBN 0-904597-46-6.
Miller, Jay (2001). The X-Planes: X-1 to X-45 (third ed.). Motorbooks International. ISBN 1-85780-109-1.
Parsch, Andreas (2024). ""Missing" USAF/DOD Aircraft Designations". designation-systems.net. Retrieved 11 May 2010.
Parsch, Andreas (2024). "DOD 4120.15-L - Addendum". designation-Systems.Net. Retrieved 11 May 2010.
Norris, Guy (February 2012). "USAF Reveals Latest X-Plane: X-56A". Aviation Week and Space Technology. Retrieved 11 February 2012.
External links
Media related to Experimental aircraft of the United States at Wikimedia Commons