To fulfill this mission requires a hypersonic aircraft with near antipodal range (20,000 km). To achieve the range requirement liquid hydrogen fuel is mandatory since the specific calorific energy of hydrocarbon fuels is too low. Reaction Engines have conceived the Scimitar precooled engine concept which exploits the unique thermodynamic properties of liquid hydrogen. This engine is capable of sustained Mach 5 flight whilst achieving an effective exhaust velocity of order 40,900 m/s. In addition the engine has a second operating mode that features a high bypass airflow permitting efficient subsonic flight and moderate takeoff noise.

Ticket Price
Analysis of the Development, Production and Operating costs suggests that the average ticket price would be comparable to an existing Business class ticket. Therefore in principle the A2 vehicle could capture all of the current business and first class traffic due to the greatly reduced journey time of 4.6 hours compared to the current 22 hours. This estimate assumes hydrogen fuel derived from water electrolysis whereas the ticket price would roughly halve if the hydrogen is produced by steam reforming. Also the analysis assumes no hydrogen subsidy, however in reality it is likely that the first generation of hydrogen fuelled aircraft would be subsidised to promote the switch to a more environmentally friendly fuel.

Unlike Concorde the A2 vehicle has exceptional range (approx 20,000 km both subsonic and supersonic) and is therefore able to service a large number of routes whilst simultaneously avoiding supersonic overflight of populated areas. Its good subsonic performance enables it to service conventional subsonic overland routes thereby increasing its sales potential to airlines.

“...to reduce long-distance flights, e.g. From Brussels to Sydney, to less than 2 to 4 hours. Achieving this goal intrinsically requires a new flight regime for commercial transport with Mach numbers ranging from 4 to 8.”