Abstract: An aircraft stores cryogenic fuel in one or more right sized fuel tanks inside the aircraft fuselage or at other appropriate positions on the aircraft, and stores non-cryogenic fuel in plural standard jet fuel tanks e.g., inside the aircraft wings. The tanks are sized to using an automated aircraft sizing computational tool based on the defined missions ranges requirements, tanks sizing logic, Top-Level Aircraft Requirements, and aircraft geometry and engine thrust levels, to iteratively develop at least cryogenic fuel tank size for a particular aircraft. A controller controls selective routing of non-cryogenic fuel or cryogenic (e.g., hydrogen) fuel to dual fuel engines. In one operating mode, the dual fuel engines normally use the cryogenic hydrogen fuel as the main fuel, and reserve the non-cryogenic fuel for application to the dual fuel engines only on an exception basis, thereby providing cleaner and more environmentally friendly operation.

Abstract: An aircraft stores cryogenic fuel in one or more fuel tanks inside the aircraft fuselage or at other appropriate positions on the aircraft, and stores non-cryogenic fuel in plural standard jet fuel tanks e.g., inside the aircraft wings. A controller controls selective routing of non-cryogenic fuel or cryogenic (e.g., hydrogen) fuel to dual fuel engines. In one operating mode, the dual fuel engines normally use the cryogenic hydrogen fuel as the main fuel, and reserve the non-cryogenic fuel for application to the dual fuel engines only on an exception basis, thereby providing cleaner and more environmentally friendly operation.