There was a US project to produce a fission powered plane, starting in 1946: https://en.wikipedia.org/wiki/Aircraft_Nuclear_Propulsion https://en.wikipedia.org/

There was a US project to produce a fission powered plane, starting in 1946: https://en.wikipedia.org/wiki/Aircraft_Nuclear_Propulsion https://en.wikipedia.org/wiki/Aircraft_Nuclear_Propulsion There were recently some rumours about the Russians producing a nuclear powered cruise missile. I'm not sure a fusion powered plane would be any less crazy. At least with D-T fusion you have a MUCH higher neutron radiation requiring more shielding. OTOH if the plane crashes there's less worry about nuclear waste spreading over the landscape.