But engineers at Aerion, Lockheed Martin and GE Aviation are working to change that. According to a memorandum of understanding they signed today in Washington, D.C, they agreed to "explore the feasibility of a joint development of the world's first supersonic business jet," and will spend the next 12 months working together "to develop a framework on all phases of the program, including engineering, certification and production."
The jet, called AS2, could shuttle as many as 12 passengers over water at a maximum speed of Mach 1.4, 40 percent faster than the speed of sound, or about 1,000 miles per hour. The plane's special design could also allow it to fly at Mach 1.2 without a sonic boom reaching the ground over areas permitted by regulation. Sonic boom is the loud sound set off by shockwaves caused by an aircraft traveling faster than the speed of sound.
The AS2 could fly nonstop from Los Angeles as far as Paris. It shrink transatlantic travel to just 3 hours, allowing executives and the jet set to turn a visit to Europe or the East Coast into a day trip.
Aerion has already spent the last 15 years developing AS2, a supersonic jet that could carry up to 12 people in high comfort from London to Seattle, Miller says. “We’ve been focusing on improving efficiency so we can lower the cost of operations and extend the range of the plane so it’s not limited to just barely getting across the Atlantic,” he says. “Now you’ve got an airplane that will really take you places.”
The company has been working with NASA and Airbus’ Defense & Space unit on finding the most optimal design for the aircraft, and with GE Aviation on selecting the best engine for the jet. “We’ve reached the conclusion that it’s not feasible to start with a clean-sheet engine design,” Miller says. “It would cost too much and take too long. With GE, we have a good opportunity to take an existing engine core and adapt it.”
The key to Aerion’s design is a concept called natural laminar flow proposed by aerodynamicist and Aerion founder Richard Tracy, who has had a hand in such diverse and innovative aircraft as the Canadair Challenger business and the single-stage-to-orbit Rockwell X-30 spaceplane concept. Supersonic natural laminar flow allows smooth layers of air to travel over wings without turbulence. Aerion has used proprietary software to design thin, composite wings with a low “aspect ratio” similar to jet fighter wings.
Unlike the delta-shaped wings of the Concorde, the Aerion wing design has a modestly swept leading edge, which promotes laminar flow. The design allowed Aerion to reduce drag over the wing by as much 60 percent. Together with a laminar flow tail and an optimized airframe, the net friction drag of the entire plane is up to 20 percent lower, “which, in aeronautical terms, is a huge leap in efficiency,” the company says.
Lower drag means that the plane can use smaller, more efficient engines and still achieve speeds of up to Mach 1.4. “Clearly, GE’s experience with supersonic engines is going to be tremendously valuable to us,” Miller says.
GE Aviation is best known for giant turbofan engines for long-distance passenger jets like the Dreamliner or the Boeing 777. But it also built the first American jet engine for the country’s first fighter jet during World War II, and its supersonic engines currently power planes like the F-16 Fighting Falcon, made by Lockheed. “Aerion sees an opportunity to pioneer a new segment in business aviation and more broadly for civil aviation,” says Brad Mottier, runs GE Aviation’s business and general aviation division. “Their goal is to design and certify the first civil supersonic aircraft in half a century.”
These types of engines are much smaller than the latest turbofans and are a good fit for Aerion. “If you look at the last 40 or 50 years, the aviation industry has achieved tremendous gains in fuel efficiency, in large part through increasing bypass ratio,” or the amount of air that flows around the engine core, Miller says. “However, the most efficient engine for a supersonic aircraft is a low bypass ratio engine, as you may find on today’s fighter jets, but these are too noisy for civil use. The solution is a moderate bypass engine that will meet today’s strict noise regulations. That will be the focus of our work with GE.”
The AS2 could take a first flight as soon as 2023 and receive certification from the FAA two years later.