Industrial engineer Charles Bombardier drew inspiration from his past supersonic creations—the Skreemr and Antipode—in creating his newest aircraft concept: the Paradoxal, a supersonic jet designed to shuttle hundreds of passengers long distances in a fraction of the time it takes a modern commercial airliner.
“I think the Paradoxal is more interesting, less complicated and probably less expensive to develop, since it would use a lot of existing technology,” Bombardier says. “I believe it could be built and operated today with some technological development.”
Resembling a stingray, the plane—which would not be suitable for autonomous operations—would be outfitted with two rim-rotor rotary ramjet engines that would give it enough power to climb to 60,000 feet and reach Mach 3. At that point, the air-breathing engines would transform into rocket engines by injecting liquid oxygen injected into the gas exhaust port, placing it on a parabolic suborbital path with an apex of 65 kilometers (approximately 40 miles)—a cruising level well above the stratosphere.
Though the plane—which would be made of standard civil aviation materials using current aircraft manufacturing techniques—would be compatible with all existing airport infrastructure and services, a few of its mechanisms have yet to be developed: for starters, the proposed R4E engines, though they could be replaced with existing turbines that use afterburners to increase thrust. And then there are the linear nozzles on the plane’s wings that would induce long penetration mode (LPM)—a natural phenomenon that could be used to cool the vehicle.
“As the speed increased to first supersonic, then hypersonic velocities, the engines or onboard tanks of compressed air would supply air to the LPM nozzles along the leading edges of the plane,” Bombardier notes. The consequent effect would reduce thermal loads while also tempering overall drag as the vehicle accelerates and climbs. Less than an hour before landing, the LPM flow would cool the plane during atmospheric reentry, slowing it gradually to subsonic speed (under Mach 1) and reverting back to the use of the air-breathing engines upon final approach.
There’s also the issue of G-forces. “The most efficient suborbital G-flight path is probably not comfortable for most civilian passengers,” admits NASA aerospace engineer Rebecca Farr, whom Bombardier collaborated with on the project. “That would be a problem for trajectory analysts to solve.”
The jet would be capable to flying from Los Angeles to Sydney, Australia in less than four hours. “Other cruise times at high altitude would be shorter, but ascent and reentry phrases will likely always take about two hours altogether for every route,” Farr notes—which means the craft would only be appropriate for very long hauls.
The best part about the journey? The view. “In mid-flight, passengers would see Earth’s curvature and multiple cameras would grant them access to a video feed of the view,” Bombardier says. “They would even get to experience weightlessness for a brief moment before heading back down.”
Sourced h/t Forbes