Aerion Unveils Engine for Supersonic AS2

Aerion is well into laying out its “technology roadmap” for reintroducing civil supersonic transportation via its AS2 Mach 1.4 business trijet, announcing the first supersonic engine in 55 years at the National Business Aviation Association's annual convention in Orlando, Florida. Dubbed the Affinity engine, the supersonic-capable GE Aviation powerplant will also meet upcoming Stage 5 environmental and noise standards. Separately, Aerion announced the AS2's avionics suite—a Honeywell Primus Epic package.

Working closely with partners on the AS2 and its possible follow-on program, Aerion has found that the borders for its technology roadmap have expanded beyond those envisioned for its AS2 supersonic business jets. “Aerion and our industry team, comprised of Lockheed Martin, GE Aviation, and Honeywell, have solved many of the tremendous challenges in creating a supersonic renaissance,” said Aerion CEO Tom Vice. 

Related Article

Aerion AS2

This supersonic business jet just got a hefty cash investment from Boeing.

Significantly, Vice discussed “next generation” aircraft. “We are starting with the AS2 because the technology closes and the business case closes. We see a viable market for the AS2. It will be our springboard to larger and faster designs, both for business aviation and commercial airliners.”

Vice continued to describe a faster (Mach 1.6), larger-cabin, longer-range aircraft that could serve as both a business jet and a small airliner. He also said, “Entirely new engine designs hold the potential to build larger aircraft able to fly at Mach 1.8 and above.” He further suggested that if and when hypersonic airplanes take to the skies in decades to come, “We expect they will say 'Aerion' on the side.”

“We’ve overcome some huge technical hurdles and we’re confident we’ll meet Stage 5 takeoff and landing noise requirements,” said Vice. He also addressed a white paper released over the summer by the International Council on Clean Transportation (ICCT) that opposed development of supersonic aircraft on environmental grounds. Even though the paper targeted mainly supersonic airliners and left business jets such as the AS2 outside its bullseye, ICCT has drawn the attention of critics of all forms of supersonic flight.

He said the Aerion team had thoroughly dissected the ICCT paper, its methodology, and its calculations. “We take this very seriously,” he said, “and we’ve developed our own paper in response.”

Regarding issues of sonic booms, he outlined research conducted by Honeywell and NASA on weather and data-collection technology that can analyze atmospheric conditions in real time and couple the aircraft’s navigation system and autopilot to ensure that no sonic boom ever reaches the ground. “We still need to incorporate vertical wind into the algorithm,” Vice said, adding that more work remains on adding additional real-time data, improving onboard sensors, and increasing weather uplink updates.

In addition, he and Brad Mottier, GE vice president and general manager for business and general aviation and integrated services, pointed to ongoing research to ensure the AS2 and any follow-on aircraft would remain within Stage 5 noise limits and within current and future emissions standards.

GE Aviation has completed the initial design of its Affinity turbofan, described as “the first supersonic engine purpose-built for business jets,” according to the company. The Affinity is a medium-bypass-ratio turbofan, a “blend of proven military supersonic experience, commercial reliability, and the most advanced business jet engine technologies.”

GE describes the Affinity as a “twin-shaft, twin-fan turbofan with next-generation full authority digital engine control (Fadec).” The company said the engine is designed to meet Stage 5 subsonic noise requirements and beat current emissions standards.

Features include a service ceiling of 60,000 feet, the highest bypass ratio of any supersonic engine, a proprietary non-augmented exhaust system (no afterburner required), a combustor with advanced coatings optimized for sustained high-speed operations, advanced acoustic technology to meet or exceed regulatory requirements, and additive manufacturing technologies to reduce weight and increase performance.

Formal launch of the Affinity program in May 2017 followed two years of preliminary study, according to GE. The next review is scheduled for 2020, when the detailed design is expected and the first test article is to be produced.

Honeywell’s Carl Esposito, president of electronics solutions, described the flight deck that will equip the AS2, saying Honeywell would “deliver a comprehensive connected aircraft solution.” He cited the company's history of developing avionics for supersonic military aircraft, and described how that experience played into integrating business aviation avionics requirements with the differences related to supersonic flight.

Asked about funding sources, Vice said the company continues to be financed by Robert Bass, and that the financial business case remains in place through development and market entry for the AS2. Non-recurring development costs are expected to total approximately $4 billion, he said. He did say that future programs could involve investment from suppliers, such as Lockheed Martin, Honeywell, and GE Aviation, and that the company is looking into incorporating outside investment.

He also said revenue streams from the AS2 program would drive future projects. But, Vice said, financial planning for future programs is in early stages. “We’re an engineering-oriented company, and that’s the way we approach our finances, as well.” He added that just as technology advances while future airplanes are being contemplated, markets and finances also evolve. “You start with the market, and we’re analyzing that,” he said. “Right now, we’re getting AS2 done.”

The recent FAA reauthorization included a mandate to study possible new noise rules for supersonic transports. Though current Part 36 noise certification rules apply only to subsonic aircraft, the FAA has said that “lighter and more efficient composite materials, combined with new engine and airframe designs, may offer the potential for introduction of a viable SST.” Proposed rules are expected to be published next year.

Dave Richardson—a conceptual design engineer at Lockheed Martin’s Skunkworks assigned to the Aerion program—said the company completed a detailed two-day review of the program in September and assessed the risk as medium to low. “There are no showstoppers,” he said. That risk assessment included a review of possible new FAA regulations.

Aerion has been working closely with the FAA, Vice said, and the agency will consider substantial amounts of data from Aerion as it develops future rules. He also cited the recent FAA reauthorization with its focus on establishing parameters necessary for supersonic flight. Besides, Vice said, the AS2 has been designed to be “incredibly efficient” in subsonic as well as supersonic flight. “It was designed to conform to current regulations,” he said.

Vice said Aerion has had discussions with some U.S. communities as to a final production site and expects to make a decision within 18 months. Aerion anticipates a market for 300 AS2s over the first 10 years and 500 total aircraft at a price of $120 million each.