Aura Aero has completed ground testing of the prototype for its Integral E electric training aircraft, which is set to make a public debut at the Paris Air Show in June before the start of flight testing. In May, the French start-up also unveiled a revised configuration for its 19-passenger ERA hybrid-electric regional airliner, for which it says the design is now frozen.
The two-seat Integral E model, powered by Safran’s EngineUs electric motor, will have a flight endurance of 60 minutes, with batteries that can be fully recharged in less than 30 minutes. The company expects to gain certification under European Union Aviation Safety Agency (EASA) CS-23 rules and have it ready to enter service, mainly with flight schools and aero clubs, in 2024.
The all-electric model is a sibling to the piston-powered Integral R and S models. Both feature Lycoming engines delivering a range of up to some 500 nautical miles, with the S model being designed more specifically for aerobatic flying. Aura Aero believes it will achieve type certification for the R model in the next few weeks, followed before year-end by the S model, which has just received the permit to fly it needs for flight testing. The company says it now holds over 100 letters of interest for three Integral models.
Aura Aero’s work on electric propulsion for the Integral family has paved the way for the ERA program; the start-up’s CEO and chief engineer Jérémy Caussade told reporters that the approach had allowed it to reduce the technology risks around electric propulsion. The company decided early on that the vehicle would require a hybrid architecture combining a turbogenerator with electric motors to deliver commercially viable payload and range to operators.
More Motors and a New Tail Improve Aerodynamics
The main change in the final design involves the use of eight electric motors powered by a combination of two turbogenerators and four battery packs through an 800-volt network. The turbogenerators will be installed in the lower rear fuselage, while the battery packs go farther forward.
An earlier design had featured just six of the wing-mounted electric motors. According to Aura Aero chief technology officer Mattia Padulo, the company’s engineers concluded that eight smaller engines could be more effectively integrated with the overall aerodynamics of the airframe and will also be easier to cool, resulting in lower maintenance costs.
Aura Aero has worked with automotive group Stellantis to refine the ERA’s airframe design, which now features a T-shaped tail and winglets for improved aerodynamics and handling. The redesign process has pushed back the timeline for the program by a couple of years with the first flight now expected to happen in 2026 and type certification to follow in 2028.
“There has been a delay, but we now have a clearer idea of what we have to do, and we also want to go carefully with the ramp-up [of the program],” Caussade said. The redesign, which now includes a 1.88 meter (74 inches) standup cabin, is also based on input from prospective customers that include a mix of passenger and freight airlines, special missions, as well as business aviation operators.
The ERA, which stands for Electric Regional Airliner, would fly to a range of up to 900 nm, at a cruise speed of up to 300 knots, and at a service ceiling of 25,000 feet. The all-electric range would be no more than 90 nm, and Aura Aero expects most airline sectors to fall between around 200 and 350 nm. The aircraft will be able to operate from runways as short as 800 meters (2,600 feet), allowing operators to launch new regional services that connect smaller communities.
According to Gwenola Robert, Aura Aero’s chief commercial officer, the ERA will cut energy and maintenance costs in half compared with current 19-seat airliners, reducing carbon dioxide emissions reduced by up to 80 percent. Operators will be able to fully recharge the batteries in no more than 30 minutes and the turbogenerators would be able to run on 100 percent sustainable aviation fuel.
Robert told reporters that over the next two decades, some 2,000 aircraft in the 19-seat market segment need replacing at a time airlines feel growing pressure to meet net-zero carbon objectives as short-haul flying dependent on fossil fuels increasingly is viewed as unacceptable. “There has been no clean sheet commuter aircraft in decades,” she said.
Prospective customers who have expressed an interest in the ERA, pending the official opening of the order book, include the following operators: Republic Airways (and its subsidiary Cape Air), leasing groups Amadeo and Green AeroLease, Commuter Air, Alpine Express, ElitAvia, Dux Forwarding, Afrijet, Flying Green, and FMS Jet Aviation. Aura Aero says it now holds letters of intent for 330 ERA aircraft.
Cost Savings Could Disrupt Regional Airline Market
“If Aura Aero can deliver the aircraft with the promised specifications, it will be very disruptive,” commented Amadeo’s chairman and CEO Mark Lapidus. “We believe the ERA will be better or at least comparable to turbine aircraft [in terms of performance]. The market needs an [electric] aircraft that can fly at altitude and distances such as London to the south of France in two hours. Access to small airports could be a very disruptive element, and the cost savings in terms of fuel burn maintenance, fewer crew, and lower airport charges are all factors our investors can understand.”
European business aircraft management company and private charter operator ElitAvia predicts growing interest in electric aviation in the market segments it serves. “We were surprised by our clients’ positive reaction to the ERA,” said CEO Michel Coulomb. “Even large business jet owners know they have to reduce their carbon footprint for short flights of just one to two hours.”
In addition to its EngineUs 100 motors, Safran holds responsibility for all aspects of power management, storage, and distribution through its GeneUsGrid high voltage technology and its GeneUsPack energy storage units. The company’s electrical and power division also provides the ERA’s turbogenerators.
Another French aerospace giant, Thales, supplies the ERA’s avionics suite, as well as connectivity systems and technology to allow the integration of energy data with the flight management systems to help operators make the best use of the available energy. Thales v-p for flight avionics, Jean-Paul Ebanga, told reporters that the flight deck will benefit from the company’s latest cloud-based capabilities to support single-pilot operations.
Both Safran and Thales also are working on another French start-up's plans to reshape the regional air mobility sector with hybrid-electric propulsion. They partnered with VoltAero in the development of the four- to 10-seat Cassio family of aircraft.
The ERA will feature a fly-by-wire system that Auro Aero is developing in-house. Padulo said the company has taken that approach because it wants to ensure full integration of the aircraft's hybrid power management system with the flight controls. “We also need to pave the way for more autonomous flight systems and increase the ratio of software to hardware to make it easier to upgrade the aircraft in the future,” he explained.
Aura Aero plans to manufacture the Integral and ERA aircraft at a new purpose-built factory in the Toulouse area. Having conducted its work since launching in 2021 on initial funding of around $50 million, the company says it will soon start seeking more capital from a wider group of investors. Cassaude said the full launch of the ERA program will happen in the next few months and that it will likely take “several hundred million [dollars]” to get the new aircraft to market.