NASA a écrit:Other X-planes will demonstrate specific technologies related to ultra-efficient subsonic aircraft designs in flight – possibilities include very long but narrow wings, forms of electric propulsion, a double-wide fuselage, or engines embedded into the vehicle.
And in a world “first,” another X-plane will be a business-jet-sized supersonic vehicle that burns low carbon bio-fuels and generates such quiet sonic booms that people on the ground will barely hear them.
The New Aviation Horizons X-planes will typically be about half-scale of a production aircraft, although some may be smaller or larger, and are likely to be piloted. Design-and-build will take several years, with vehicles going to flight starting around 2020 depending on funding.
Un des premier X-plane prévu sera probablement un hybride aile volante avec fuselage, un peu comme celui que LockMart a présenté il y a quelques années (voir image ci-desous)