The road to a supersonic business jet has been excruciatingly slow, and most who have taken a stab at developing one over the last four decades have either folded, used the venture to secure government research grants, or relegated it to the back burner in favor of more economically expedient projects.
The reasons are myriad. The effort requires enormous up-front cash and involves daunting technological challenges, potentially toxic environmental politics, and seemingly insurmountable regulations. And the chances for investment recapture remain highly uncertain, not least because supersonic flight over land by civil aircraft over the U.S. and Europe remains illegal.
Still, we seem to be nudging ever closer to a supersonic reality as it is becoming de rigueur for new large-cabin conventional business jets to offer high-speed cruise maximums of at least Mach 0.90—515 knots at 40,000 feet. While surviving copies of the Anglo-French Concorde supersonic jetliner ended up in museums, its rarefied clientele is still out there—and they still want to go fast, even if only over the oceans. Some of them would have no problem plunking down $120 million for a supersonic eight- to nine-seater or forking over $20,000 or more an hour to charter one.
Late last year, fractional operator Flexjet signed a letter of intent for 20 supersonic Aerion business jets that it plans to offer to its Global Lease customers who need supplemental and expeditious transoceanic lift. If successful, the Aerion AS2 trijet will fly at Mach 1.5, or about 67 percent faster than a conventional business jet, and will make the trip from New York to London in less than four hours. Right now, that airplane appears to be the supersonic project that’s closest to reaching the market, but even it won’t appear before 2023.
Backed by an initial $100 million investment from billionaire Robert Bass, aerodynamicist Dr. Richard Tracy helped to found the company that became Aerion in 2002. Decades earlier, Tracy worked with bizjet legend Bill Lear, developing the aircraft that became the Canadair (later Bombardier) Challenger 600, and worked on classified U.S. defense programs. In 1994, he patented the supersonic natural laminar flow wing concept, the basis of the Aerion’s design and an idea that first crossed his mind in 1959.
Laminar flow involves the air next to the wing. At supersonic speeds it can flow smoothly, free of turbulence, with less drag on the wings, resulting in better speed, range, and fuel economy—but only if the airplane’s design takes advantage of it by eliminating drag-inducing things such as highly swept wings. If you look at the renderings of the AS2 on these pages, you’ll see that the wings are short, thin, and stubby. That’s to benefit from supersonic natural laminar flow.
Bass built a solid team around the project that includes cochairman Brian Barents, the former Learjet CEO; CEO Doug Nichols, the former Boeing CFO for the commercial 747/767 programs and for Boeing Business Jets; chief commercial officer Ernie Edwards, the former president of Embraer Executive Jets; and senior vice president for aircraft development Mike Hinderberger, who had been the chief engineer on Gulfstream’s wildly successful G650.
However, Aerion arguably got its biggest boost in late 2014 when it signed a technology-sharing agreement with Airbus Group, whose predecessor company, Aerospatiale, was the co-developer of the Concorde, along with British Aerospace. Under the deal, Airbus agreed to assist with the design, construction, and certification of the AS2.
The agreement already has borne tangible results. Earlier this year, Aerion CEO Doug Nichols said that Airbus had been instrumental in helping with the design of an articulating landing-gear system, the fuel system, the computerized fly-by-wire flight-control architecture, and the carbon-fiber wing, fuselage, and empennage structures.
Aerion still hasn’t selected the engines. The original design featured two Pratt & Whitney engines, but they are being discontinued because they won’t meet future anti-noise standards. New-generation bizjet engines should fit the bill in the current three-engine configuration and Aerion is expected to make a decision soon. The company’s data shows that the aircraft can operate efficiently at high subsonic speeds of Mach 0.95 and that at low supersonic speeds of Mach 1.1 to Mach 1.2 it can actually fly at cruise altitude without its sonic boom reaching the ground, a phenomenon it calls “boomless cruise.” Aerion hopes to use its boomless-cruise data to get the U.S. Federal Aviation Administration and regulators in other countries to lift the ban on supersonic flight over land for its aircraft at those speeds.
As you’d expect from a supersonic design, the AS2 will be a big beast and will need lots of pavement when fully loaded. Nose to tail it measures 170 feet—70 feet longer than a Gulfstream G650. Maximum takeoff weight is 121,000 pounds. Balanced field length is 7,500 feet. However, with lighter loads, the AS2 should be able to comfortably operate out of popular business airports such as New Jersey’s Teterboro, outside New York City, and still have a 4,000-nautical-mile range.
The AS2’s two-zone cabin is a lot shorter than what you usually find in a long-haul, large-cabin bizjet. It’s just 30 feet long, compared with the G650’s nearly 47 feet and the Falcon 8X’s 43 feet. However, the AS2’s cabin is typical of what you’ll find in aircraft with the same range. The 4,750-nautical-mile Falcon 900LX, for example, has a 33-foot cabin. And at Mach 1.4 in the AS2 you are spending a lot less time there.
Dimensionally, the AS2’s cabin is a different cat. While its maximum height is just over six feet and its maximum width is seven and a half feet, those dimensions aren’t uniform; supersonic aerodynamics mean that the fuselage has to have a non-constant cross-section. There will be more room in the aft half of the cabin, but as you move forward the fuselage tapers. It isn’t terribly noticeable as most of the tapering occurs in the galley and cockpit areas and you’ll be able to configure the AS2 cabin with traditional layouts, including double club with eight single seats, club four with conference grouping and table opposite a credenza, and club four followed by half club opposite a three-place divan. You’ll be able to access the baggage hold through the aft lav and a forward crew lav will be optional.
For now, Aerion continues development work with Airbus and is searching for a manufacturing and flight-test location—some place with a long runway, near an ocean. The company hopes to be flying the first prototype by 2021. The wait to go fast is going to last a little longer.