Regarding the “supersonic is now viable because LNG” argument, but for a different reason than usual.
Even if supersonic flight becomes cheaper via new fuels or propulsion, that doesn’t reset the baseline. The same advances (materials, engines, fuel handling, manufacturing) will also apply to subsonic aircraft, where the physics are already far more energy-efficient. So if supersonic gets “cheap,” traditional jets will get much cheaper. Airlines will always arbitrage toward the lowest energy-per-seat-km for most routes, and supersonic flight is structurally disadvantaged there (drag, noise, routing constraints).
Historically, faster transport doesn’t replace slower transport wholesale; it creates a premium tier while pushing the mass market down to a lower cost/energy equilibrium. Concorde didn’t kill widebodies, widebodies got cheaper. My intuition: supersonic may of course exist as a niche (time-sensitive, premium), but its biggest impact would be indirect, accelerating efficiency gains that make conventional aviation even more dominant and cheaper.
Even if supersonic flight becomes cheaper via new fuels or propulsion, that doesn’t reset the baseline. The same advances (materials, engines, fuel handling, manufacturing) will also apply to subsonic aircraft, where the physics are already far more energy-efficient. So if supersonic gets “cheap,” traditional jets will get much cheaper. Airlines will always arbitrage toward the lowest energy-per-seat-km for most routes, and supersonic flight is structurally disadvantaged there (drag, noise, routing constraints).
Historically, faster transport doesn’t replace slower transport wholesale; it creates a premium tier while pushing the mass market down to a lower cost/energy equilibrium. Concorde didn’t kill widebodies, widebodies got cheaper. My intuition: supersonic may of course exist as a niche (time-sensitive, premium), but its biggest impact would be indirect, accelerating efficiency gains that make conventional aviation even more dominant and cheaper.