Heart Aerospace is changing the certification basis of its ES-19 all-electric aircraft, moving to a heavier weight category in order to better address the market, particularly in the USA, a decision that will result in the “most significant design change” to the type since the start of the programme.
Initial plans from the Swedish start-up called for certification under the European Union Aviation Safety Agency’s (EASA’s) CS-23 commuter category, which covers aircraft with a maximum take-off weight (MTOW) of up to 8,618kg (19,000lb) and accommodating no more than 19 passengers.
Although the ES-19 was likely to exceed that weight limit, Heart had been seeking an exemption from the regulator.
However, it now plans to obtain EASA validation under the agency’s CS-25 large aircraft category, which applies to types with an MTOW above the 8,618kg limit.
Founder and chief executive Anders Forslund says the move will allow Heart to avoid any design limitations imposed by the CS-23 rules.
In addition, the US Federal Aviation Administration (FAA) restricts the operation of CS-23 aircraft - what it calls Part 23 aircraft - to non-scheduled commercial operations.
With US carriers Mesa Airlines and United Airlines having ordered a combined 200 ES-19s between them, the certification basis was clearly “something that had to be dealt with”, says Forslund.
Heart was already incorporating features in the ES-19 that are suitable for CS-25 certification, such as the avionics and fly-by-wire flight controls, he says, therefore “it is not that big a jump up anyway”.
He adds: “This is one of the most major and most consequential design decisions that we have taken since the programme’s inception and it is resulting in the most significant design update to the aircraft as well.”
However, Forslund remains coy on the changes that will now be incorporated into the ES-19 or the proposed MTOW or passenger capacity.
These will be revealed during a hangar day to be held at the airframer’s Save airport base near Gothenburg in mid-September.
“What I can say is some of the things that have not changed: we are still doing this with the partner airlines and all the suppliers we are working with. We have made this decision jointly.”
The “design philosophy” remains the same, he says, with an emphasis on “de-risking” the development, for example using an aluminium rather than composite fuselage and wing.
“All these things are very much the same, but having said that when you see the new aircraft you will see the design has been updated – it is not dramatic but it is recognisably different.”
Current renderings of the ES-19 show a high-wing aircraft powered by four electric motors and featuring upswept wing-tips and a T-tail.
Heart has been developing its own electric powertrain for the ES-19, but Forslund declines to confirm if this will be employed on the eventual production aircraft.
He foresees only minimal impact to the ES-19’s development timeline from the change: service entry is still planned for 2026.