After Sir Richard Branson launches the first passenger flight of his Virgin Galactic space venture, possibly later this year, he’s indicated that he will turn his attention to developing a supersonic commercial aircraft that can transit from New York to Tokyo (10,800 km; 5,800 nm) in “less than an hour.” He envisions an orbital aircraft, which could reach speeds up to 30,000 kph (16,200 knots).
Branson is not the only billionaire entrepreneur who would like a means of getting to the other side of the world far more quickly. Texas tycoon Robert Bass continues to make substantial investments in support of Aerion’s plans to bring a supersonic business jet to market.
Governments have provided research expertise and funding support in the hundreds of millions of dollars range as well through NASA and DARPA in the U.S., and the UK’s more than $600 million budget for Reaction Engines’ hypersonic dreams.
Then there is Spike Aerospace, whose 12- to 18-passenger, Mach 1.6 S-512 design is still on paper and not yet taking orders–but it created some buzz earlier this year when Spike announced a “windowless” fuselage. At $100 million or more per aircraft, the company expects to recoup its investment from sales of an estimated 400 to 500 supersonic planes in the next decade, according to Vic Kachoria, president of Spike Aerospace, based in Boston, Massachusetts.
Digital Cabin
Kachoria said due to the lack of windows, it now refers to the “digital cabin.” “You’re going to be able to see outside, but you’re going to get a more enhanced view. The entire length of the fuselage can be one continuous panoramic image,” he explained.
The “outside” that passengers see will not be a direct view. Rather, several small cameras mounted on the exterior of the aircraft will be able to relay images of the day or night sky, projecting them onto a cabin wall that is, in effect, one long, high-resolution display screen. If you prefer, or whoever has control of the display controls prefers, you can also project a Powerpoint presentation, an Excel spreadsheet, a videoconference, a movie–or nothing, if you’d rather sleep.
Kachoria, who describes himself as a “serial entrepreneur,” said that despite the “Oh, my god, it doesn’t have windows” reaction of some and concerns about claustrophobia, windowless aircraft will be the norm within 20 years. Replacing windows, spurs and supports with a streamlined fuselage is simply one element of increasing the speed envelope.
Spike is “at a very early stage; we have a lot of engineering and design work to do,” Kachoria acknowledged. Spike is currently evaluating the preliminary design it announced last October, performing simulation analysis. “We probably have at least another year of heavy engineering work, but we’re definitely moving forward. There’s a demand for supersonic flight, and it’s doable in the next five to eight years.”
Quiet Enough?
The most challenging part of the process, he thinks, will be securing FAA certification–in part because of new noise regulations. ICAO’s new Annex 16, Chapter 14 noise standards are expected to be in effect for bizjet category aircraft by 2020, and the company is in discussions about potentially unique requirements for supersonic aircraft as well.
The new noise regulations are also uppermost in mind for Aerion, which announced in May a three-engine concept rather than its original twin-jet design. “The new noise regulations absolutely mandated a new engine,” Aerion CEO Doug Nichols told AIN. “Noise drives the design; noise drives the engines. The noise regulations were the cause of moving beyond the [Pratt & Whitney] JT8D turbofan, which Aerion had been planning to use in its original two-engine configuration.
“With three engines, and each engine at two thirds of overall thrust,” Nichols explained, “the jet velocity out of each engine is lower so the overall noise signature is lower.”
The tri-jet design will also be a benefit for long routes over water or uninhabited land areas where unrestricted supersonic speeds are permitted. It also enables a larger cabin compartment, which appeals to some potential customers. But Nichols said the third engine does not fundamentally affect the aircraft’s design. “We have not discarded all of the work we have done. We have built upon this work. A layman won’t discern any difference at all.
“We are well along into the conceptual design phase,” Nichols said. “We have spent an inordinate amount of time over the past decade working with NASA in phased approaches to testing our technology in terms of our design tools that allow engineers to know, based upon the wind geometry, when laminar flow can become turbulent, and then optimize the wing so we get the largest possible extent of laminar flow and minimize turbulent flow. And we have tested the robustness of our technology given state-of-the-art manufacturing capability.”
Aerion, now 12 years into the project, has resumed searching for an engine manufacturer “in order to converge on the optimum engine propulsion system for the airplane.” Once the new engine is selected, Nichols indicated that Aerion can focus on the aircraft’s performance capability and then proceed into the detailed design phases. Aerion also has not given up looking for an aircraft-manufacturing partner to help it build what is now dubbed the AS2. “We’re driving hard to put all the pieces in place to certify this airplane in late 2021,” he said.
Spokesman Jeff Miller said Bass’s decision to fund the aircraft development means Aerion “is not dependent on the OEM or other resources, and that’s changing the nature of the discussion.” He said the company hopes to assemble the consortium of key partners “perhaps by NBAA [the business aviation event in Orlando, Florida, in mid-October].”
Boom or Bust
Gulfstream Aerospace (Chalet J3) continues low-key efforts to research supersonic options, but according to spokesperson Steve Cass, they’re interested only in an aircraft that can be used overland and receive U.S. Federal Aviation Administration authorization, that is, one that does not create a discernible sonic boom.
Robert Pearce, NASA’s director for strategy, architecture and analysis in the Aeronautics Research Mission Directorate, told an American Institute of Aeronautics and Astronautics conference in June, “If we can overcome the challenges of the boom, I think that will become a very important part of the aviation system.”
Further downstream are the hypersonic concepts in the Mach 3+ range. Hypermach Europe Aeronautics announced its SonicStar airframe design in 2011, though it has been low on the radar recently. The company has reportedly conducted some wind-tunnel tests. Originating as a U.S. company focused on electromagnetic drag-reduction engine technology, SonicBlue Aerospace, Hypermach claims to be “supported by the UK government,” though it has yet to receive any financial support from it.
Oxford-based firm Reaction Engines (run by Alan Bond, of Hotol fame) has secured initial funding of $100 million from the UK government for development of a lightweight engine called Sabre, intended to power Europe’s proposed reusable Mach 5 Skylon spaceplane.
Skylon would operate like an airplane, taking off from and landing on standard runways. The Sabre engines would function like jet engines at low altitudes and slow speeds, but kick into rocket mode at high altitudes. The European Space Agency thinks Skylon could be flying as early as the 2020s.
