As used here, an experimental or research and development aircraft, sometimes also called an X-plane, is one which is designed or substantially adapted to investigate novel flight technologies.[1][2][3]
Solar Impulse Project – Solar power technology demonstrator
United Kingdom
Avro 707 research aircraft in formation with Avro Vulcan bomber prototypesFairey Delta 2 research aircraftGloster E.28/39 jet engine research aircraftMiles M.35 Libellula canard research aircraft
Bell X-1 supersonic research aircraftBell X-5 variable-sweep wing testbedNorth American X-15 hypersonic rocket-powered research aircraftGrumman X-29 forward swept wing and stability research aircraftMcDonnell Douglas X-36 in flightBoeing X-48B from above
US Army Bell 533 high speed helicopter research aircraftXFV-12A on ramp at NAA in Columbus, OhioScaled Composites Proteus in flight during 2002 for US Department of Energy ARM-UAV program