Safran Electrical & Power will shortly hand over the first conforming example of its newly certificated ENGINeUS 100 electric motor to launch customer Diamond Aircraft as it targets service entry next year.
Diamond has already flown an earlier version of the 125kW-rated powerplant in its eDA40 prototype as part of the motor’s certification campaign, but the arrival of the production-standard version will mark the start of whole-aircraft flight testing.
“In March we will deliver the first certification standard motor to Diamond Aircraft,” says Giovanni Raimondi, machines and drive systems technical director at Safran Electrical & Power.
“They will follow that with aircraft certification testing. So we anticipate being in a position to start shipping actual production hardware to end customers once this phase is completed.”
Raimondi says there are only “minor differences” between the production version and the pre-certification motor Diamond has been flying for around 18 months.
“We have done a certain number of robustness improvements but there are no fundamental changes to the architecture or performance,” he adds.
The ENGINeUS 100 was the first electric motor to be approved under the European Union Aviation Safety Agency’s (EASA’s) Special Condition E-19 rules – a brand new set of regulations for electric propulsion.
While some aspects of the certification mirror those for a combustion engine, inevitably there are differences.
For example, in certain circumstances, the inability to decouple the propeller from the motor can cause “uncontrolled electrical generation”, while a high-voltage electrical distribution system poses the risk of partial discharge effects.
In both cases “we needed to prove, and EASA obviously needed to see the proof” that Safran’s design solutions could control or prevent those conditions.
Safran will build the ENGINeUS family of motors at two sites: Pitstone in the UK is responsible for manufacturing the windings and other sub-assemblies, while production of the integrated power electronics and final assembly will take place in Niort, France.
Initial capacity when the factories come on stream in 2026 is for around 1,000 motors per year, a figure in line with Safran’s demand forecasts, based on conversations with its customers and the increasing electrification of general aviation applications.
While the launch programme, the three-seat eDA40, is a conventional take-off and landing aircraft, Safran has customers for ENGINeUS motors across a range of applications, including short and vertical take-off and landing vehicles.
Initial certification covers the Diamond-specific B1 version of the motor. But the EASA approval is for a family of motors, spanning the power range up to 180kW at take-off. Several subsequent models – designated B2 to B5 – are “following close behind”, says Raimondi.
There are no architectural changes between the different versions, he adds, but as the power grows, so does the length of the motor, beyond the 35.4cm (14in) of the B1.
Raimondi will not be drawn on when the next version will enter service, simply saying that “we are anticipating fairly quickly to be seeing more than one physical size of machine coming off the production lines”.
At present, Safran’s product range comprises the ENGINeUS 100 and future ENGINeUS XL, a 750kW-plus motor designed to address the “smaller end of the turboprop market”.
Although other motor manufacturers have already embarked on development of motors capable of 1MW and above, Safran’s strategy is different, adds Raimondi.
“Our initial focus is on the smaller end of the market as a stepping-stone towards a larger unit,” he says.
“We want to learn what we can in a more controlled manner and gain market intelligence and in-service knowledge as early as we can to help the maturation journey for larger product.”
Whereas other manufacturers have promoted the stacking of individual motors to deliver a higher overall output, stacking the ENGINeUS “is not an option” as it is “designed as a structural element in itself” with the propeller loads transmitted through the structure of the motor.
Stacking “does not entirely rule out the possibility of handling those loads” but it makes it “quite a bit more complex”, says Raimondi. “We don’t feel it’s the right way to go.”
