Ever since Concorde retired in 2003, commercial flight hasn’t been as insanely fast as it used to be. That doesn’t mean aerospace engineers have given up on getting you from New York to London any faster, though. Airbus recently filed patent documents for a new hypersonic aircraft with no less than three engine types to boost itself up to Mach 4.5.
With a big delta wing, pivoting stabilizer fins, retractable engines and passenger seating in hammocks, this concept is one of the more futuristic ideas we’ve seen recently. The video below by PatentYogi provides some great animations explaining how the new Airbus design would work.
So, after taking off horizontally from a runway using power from the turbojets slung underneath the fuselage, the aircraft would accelerate to a given altitude before firing the rocket engine in the tail. At this point, the turbojets would retract into the fuselage and the aircraft would orient itself vertically, breaking the sound barrier for the first time.
The design also aims to decrease the impact of sonic booms, the Concorde’s Achilles heel which prevented it from being able to fly over land routes at supersonic speeds. By crossing the sound barrier after the aircraft has transitioned from horizontal to vertical trajectory, the shock waves would expand while parallel to the ground. If the waves do not intersect the ground, the disturbance (loud noise, violent shaking, windows breaking, etc.) normally associated with a supersonic aircraft would become a non-issue.
Once the aircraft exceeds the speed of sound, the fins (shown in the vertical position in the drawings above, labeled a1 and a2) would pivot from horizontal to vertical. In the vertical orientation, the fins help to stabilize the aircraft’s climb by balancing the rocket engine’s center of pressure.
The tail-mounted rocket engine would take the Airbus concept well above 100,000 feet in altitude, at which point it would shut down and retract behind a fairing. The aircraft would then level off, and once re-oriented into the vertical position, the ramjets (labeled ST1 and ST2) would kick in, sending the Airbus up to an estimated speed of Mach 4.5.
Ramjets are a special kind of jet engine that work best for sustained supersonic cruise. Unlike other jet engines, they compress incoming air not with a compressor stage in the engine’s core, but by squeezing it around a cone-shaped spike. The compressed air is then injected with fuel and the mixture is ignited, producing tremendous thrust which is then expelled through the nozzle in the rear.
Theoretically, this new Airbus could reach London from New York City in just one hour. This would be much faster than Concorde ever made the voyage, which averaged around 3 hours and 30 minutes for the transatlantic journey. The vehicle would likely be much smaller than the Concorde, only carrying an estimated 20 passengers at a time.
Unfortunately, this idea is likely to remain in concept form for the near-term future, and possibly forever. Companies often apply for patents and trademarks to protect their intellectual property,even if they never intend to test or build the concept. Oftentimes, such patent filings are even made to drum up PR. While exciting, we have to view this idea through the prism of reality.
There could be military applications for the design, either for high speed strike missions or high altitude reconnaissance (such as the SR-71 Blackbird). Still, with a total of six engines made of three totally different types, the propensity for something to go break or go wrong in flight could make the concept totally unaffordable for most militaries.
While we would love to see a new supersonic transport like this Airbus concept zooming through the atmosphere, the costs of research and development and the low passenger volume (can you imagine the price of a ticket?) are clear indicators that this is more than likely just an engineer’s dream.
Photo credit: Top shot via embedded YouTube, Airbus patent drawings via US Patent and Trademark Office/Public Domain, Ramjet schematic by Cryonic07, Emoscopes and Wolfkeeper/Wikicommons
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