The selection of GE Aviation as the engine provider for the AS2 supersonic powerplant marks the “final real piece” of technology to clear a path to formal launch, possibly early next year, said a top executive from Aerion.
Aerion and GE on May 21 announced that the two organizations have launched a “formal and gated” process to define a potential AS2 engine.
“We have thoroughly evaluated over two dozen civil and military engines from all leading engine producers over the past two years and believe that working with GE Aviation will help us meet the challenging specifications needed to met our performance objectives, as well as the high expectations of our customers,” Aerion CEO Doug Nichols said.
Aerion was not seeking an off-the-shelf engine, but it did search for a candidate commercial core that could be “suitably adapted” to use in supersonic flight, Nichols said. Aerion ruled out use of any military engines, although he said they found some interesting candidates. But Aerion did not want to run into U.S. export restrictions on military equipment.
Aerion further ruled out starting from scratch with a brand new engine, he added, saying such an effort would have been a “massive undertaking” that would have increased development time and cost and introduced additional risk.
In the end, he said, “GE had the best engine to meet our needs,” and added that, “when we converge to launch point, which is not too far away, this aircraft will have a GE engine on it.”
While Nichols notes that Aerion still has to clear a few more obstacles, the company is hopeful that formal launch now can come in early 2018.
Aerion and GE have identified an in-production commercial core that will be adapted with a lower bypass ratio than is currently used and a smaller diameter fan. Aerion is looking at the 15,000- to 17,000-pound-thrust range, but Nichols said that will be hashed out over the next several months as definition continues. “All of this will start to gel over the next three, four, five months,” he said, adding that the collaboration may have more details finalized by this fall’s NBAA convention. “We are at the stage now where we can move very swiftly."
The AS2 will be powered by three engines and produce subsonic speeds of up to Mach .99 for flight over land to supersonic speeds of up to Mach 1.5 for long-range cruise over water. This will make the airplane commercially viable, without necessitating a regulatory change. Nichols said that Aerion has been actively involved in working with industry associations and regulators on the possibility of developing new regulations long-term that could eventually open supersonic flight further.
Aerion’s plans call for first flight about five years after launch with certification following two years later, estimated at 2025.
Nichols underscored the importance of the engine selection, calling it the most challenging technical piece with the aerodynamics of the airframe already ironed out. “The engine is the key technical piece…no engine, no airplane,” he said. “The challenges for Aerion are no longer technological.”