Build us a Mach-2.2 electric engine where the aircraft design closes and we'll use it! We're an airframer, not an engine company. Would love to see some innovation in engines. Maybe a good idea for another YC startup.
The point is that you're building a vehicle that (I assume) will produce far more pollution (CO2 and otherwise) per passenger mile than existing aircraft. Is that an ethical thing to do at this point in time?