Regional aircraft start-up Maeve Aerospace expects its in-development Maeve Jet will use hybrid-electric open-rotor engines derived from the system RTX is developing under a demonstrator programme using a modified De Havilland Canada Dash 8-100 turboprop.
Maeve chief technology officer Martin Nusseler says RTX’s Hybrid-Electric Flight Demonstrator programme is “maturing the technology” for an entirely new propulsion system that will power the Maeve Jet, an envisioned 76-100-seat aircraft the Dutch company aims to have in service by 2033.
“We have a new engine, which is in development: a clean-sheet engine,” Nusseler told FlightGlobal on 18 September. “This is only possible with a clean-sheet design, because this engine needs much higher integration into the aircraft.”
RTX’s Dash 8 hybrid programme is “maturing the engine technology” that will be used on Maeve’s aircraft, he adds.
Maeve, which in recent days secured high-profile partnerships with US carriers Delta Air Lines and SkyWest Airlines, pitches the Maeve Jet as a replacement for existing 50- and 76-seat regional jets, including Embraer 175s and MHI RJ Aviation CRJ200s and CRJ900s. This week Nusseler was in Washington, DC at the annual conference of the Regional Airline Association, which represents the USA’s largest regional carriers.
RTX and Maeve had disclosed their partnership in 2024, saying RTX subsidiary Pratt & Whitney Canada would help design the propulsion system for Maeve’s conceptual aircraft, which was then called the M80 and was to have twin wing-mounted hybrid-electric powerplants.
Since then, the M80 has evolved into the Maeve Jet, powered by a pair of hybrid-electric open-rotor engines located at the rear of the fuselage.
RTX has several hybrid-electric development programmes under way, including the Dash 8 Hybrid-Electric Flight Demonstrator effort and a separate project with Franco-Italian turboprop manufacturer ATR.
Pratt & Whitney and sister RTX company Collins Aerospace have been working on the Dash 8 programme since at least 2019. It involves replacing one of the Dash 8’s PW120 turboprops with a hybrid system composed of a new “highly efficient” P&WC thermal engine mated to a 1MW electric motor developed by Collins. The system has a 200kWh battery package supplied by Swiss firm H55.
RTX has been developing and ground testing the system in Longueuil, Quebec. The project is already several years behind schedule.
In June during the Paris air show, RTX said it ground tested “the integrated propulsion system and batteries at full power”, and that US firm AeroTEC, working out of Moses Lake in Washington state, will assist with modifying and flying the Dash 8.
“We have run the engine through the full cycle on the ground,” RTX chief scientist Michael Winter told FlightGlobal on 17 September. “We actually were able to achieve and exceed the take-off power of 1,800 shaft horsepower that’s required. That’s really important because… the rate that you can pull the electricity out of the batteries was one of the pinch points.”
The Dash 8 has been moved to Moses Lake and “the engine is going to be transferred there very shortly. Then it will be integrated onto the airplane to get ready for the first flight”, Winter says.
He declines to say when that flight might happen, adding: “We’re doing this to learn. We’re going to fly it when we are ready.”
Though the Dash 8 programme involves a traditional wing-mounted turboprop configuration, Nusseler says the core of the system can be modified into an open-rotor design.
Maeve – named after a queen in Irish folklore – has no exclusivity on the RTX hybrid-electric system, Nusseler notes, adding that it will complete the work of adapting the powerplant and integrating it onto the Maeve Jet, which is to fly at Mach 0.75 and have 1,000nm (1,850km) of range.
Nusseler says the hybrid-electric system will see the electric motor supplementing the thermal engine during take-off and when flying at slow speeds, while the turbine alone will power the aircraft during cruise allowing the batteries to be recharged. The parallel hybrid configuration allows for the thermal engine to be optimally sized for better fuel efficiency.
The result will be an aircraft offering 35-40% lower fuel burn than today’s regional jets, Nusseler says.
The Maeve Jet will not have an auxiliary power unit, nor will bleed air need to be drawn from the powerplant, instead using the electrical system to power both the environmental-control and anti-icing systems.
Maeve hopes next year to close the Maeve Jet programme’s concept-design phase, and then to progress through preliminary and critical design reviews.
Nusseler declines to comment about Maeve’s finances. The company has about 30 employees.
While Maeve expects the aircraft will have a metallic fuselage, it has not settled on whether the wing will be metallic or composite. Nor has Maeve decided where to produce the aircraft: Nusseler says North America and Europe – though probably not the Netherlands – are on the table, says Nusseler.
Maeve aims to complete first flight in 2030. “This is a robust, eight-year development plan which we have in place, with [a] sufficient two-and-a-half years for certification,” Nusseler says.
