X43 or X-43 may refer to:
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Lancashire bus route X43, or The Witch Way, long-standing bus route in England
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NASA X-43
The NASA X-43 was an experimental unmanned hypersonic aircraft with multiple planned scale variations meant to test various aspects of hypersonic flight. It was part of the X-plane series and specifically of NASA's Hyper-X program. It set severa ...
, unmanned experimental hypersonic aircraft
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