NASA&#x27;s previous X-Plane initiative seemed to end without making any substantial change to civil (non-military) aviation.<p>We could really use small jets out here in sparsely-populated Western USA. Eclipse Aviation got very close, then ran out of money. How much money would be required to start them up again?<p>We need new engines. My 1966 Cessna 172 required leaded AV gas, which is as rare -- and as damaging -- as the tears from a weeping unicorn.<p>Why invest in supersonic transport? We need low-end disruption, not high-end incremental improvements.