A little-known NASA project is funding the study of a next-generation commercial airliner concept that combines turbofan engines, electric tail fans, and a unique “double bubble” fuselage designed to add lift.
Hybrid-electric regional aircraft developer Electra on Monday unveiled the concept, which per the company’s analysis could deliver a 17 percent improvement on current projections for efficiency gains through 2050. The concept was borne out of NASA’s Advanced Aircraft Concepts for Environmental Sustainability (AACES) 2050 project, which is funding studies into new aircraft technologies—including advanced propulsion, fuels, and airframes—which could reshape commercial aviation in the 2040s, 2050s, and beyond.
Electra was one of five recipients of contracts NASA awarded in 2024, totaling $11.5 million. The company in a news release said the new concept creates a “near-term electrification pathway,” implying it could be adopted before 2040.
“Industry will not bring this concept to maturity by 2050 on its own,” said Parker Vascik, Electra’s director of project strategy. “That will require a NASA-accelerated technology initiative—in a double-bubble X-plane, multi-megawatt integrated generator, and kilovolt-class power distribution—to bring these capabilities to maturity by 2035 and position industry to carry them into service by 2050.”
Several airlines’ ambitions for regional aviation may have taken a blow following the bankruptcy of Maeve Aerospace, which had been developing a hybrid-electric regional aircraft for up to 100 passengers. NASA aims to restore hope that the technology could arrive within the next few decades.
Beyond Electra, the space agency is working with blended-wing body aircraft developer JetZero to enable the use of supercooled liquid hydrogen as commercial aviation fuel. It plans to test its solution on conventional tube-and-wing aircraft as well as its flagship Z4.
Pratt & Whitney Canada under its AACES contract is exploring an array of propulsion technologies designed to reduce fuel burn and carbon emissions. The company is also part of NASA’s X-66 Sustainable Flight Demonstrator project and is tinkering with its own Hybrid-Electric Flight Demonstrator, a modified de Havilland Dash 8-100.
The Georgia Institute of Technology is studying alternative fuels, propulsion systems, and aircraft configurations that it plans to integrate and test on novel aircraft concepts. Aurora Flight Sciences, part of Boeing, is performing a comprehensive study of new technologies and concepts that could be introduced within the 2050 timeframe.
“Through AACES, NASA is pushing the industry to think boldly, to use our novel propulsion technologies to unconstrain design thinking for the next generation of commercial aviation,” said Electra CEO Marc Allen.
Outside Electra, a handful of private developers are pursuing their own hybrid-electric regional aircraft concepts. These include Canada’s Evio, France’s Aura Aero, Vermont’s Beta Technologies, and GE Aerospace, which recently began testing a hybrid-electric engine system.
Electra’s Concept
Electra is developing the EL9 Ultra Short, a hybrid-electric, nine-passenger model designed for operations out of soccer field-sized spaces. The company’s AACES 2050 concept explores how the hybrid propulsion system could power a larger airliner designed for 100-plus passengers.
The narrowbody concept would be large enough to accommodate a twin-aisle cabin. Per Electra, the double bubble fuselage is designed to improve lift. The EL9 instead uses a blown-lift propulsion system, directing airflows over the wing and toward the ground to take off at a leisurely 35 knots and shorten its runway requirement.
Electra’s chief engineer for research and future concepts, Alejandra Uranga, led development of the company’s new design. Uranga previously co-led research on the Aurora D8, the original double bubble aircraft borne out of NASA-funded research at the Massachusetts Institute of Technology (MIT).
The D8 was never produced. But Electra said the concept “revisits” Uranga’s earlier work.
“This concept builds on years of research into how airframe shape and propulsion placement can work together to improve aircraft efficiency,” said Uranga. “What is different now is the ability to use electrification and distributed propulsion to more deeply integrate those systems.”
Electra’s initial AACES concept, shared by NASA in 2024, features five propellers on either side of the wing’s leading edge. The new design replaces these with twin turbofan engines, designed to provide thrust as well as electricity to three electric tail fans. The fans “ingest and re-energize slower-moving air over the fuselage,” Electra said.
The concept is designed to fit within existing airline and airport operations, fitting into standard gates and running on standard jet fuel or sustainable aviation fuel (SAF). Like Electra’s EL9, it would not require ground-based charging systems.
“We can radically improve how the airframe and propulsion system work together while keeping the aircraft grounded in real airline and airport operations,” said Vascik. “The goal is not just efficiency on paper, but concepts that we can actually build, certify, and use.”
As part of the work, Electra developed an electrified aircraft design suite within NASA’s Aviary, an open-source software platform, that is intended for use by the wider aviation industry. The team that assisted on the concept includes American Airlines, Honeywell Aerospace, Lockheed Martin’s Skunk Works, MIT’s Department of Aeronautics and Astronautics, and the Aircraft Systems Laboratory at the University of California in Irvine.
Electra is already flying a two-seat prototype, the EL2 Goldfinch, and recently completed its first urban testing in Charleston, South Carolina. Readers could see the Goldfinch—and potentially the EL9—flying in states including Florida, New Jersey, and Pennsylvania as soon as September following Electra’s selection for the FAA’s advanced air mobility (AAM) test program earlier this year.