Hybrid-electric aircraft developer Heart Aerospace is readying for the roll-out of its first full-scale ES-30 demonstrator in the early autumn, with the test asset nearing completion.
Wing installation is planned to take place this week or early next at its Gothenburg, Sweden site, chief executive Anders Forslund said, speaking to FlightGlobal on 24 July.
“It is very nearly finished, everything is coming along nicely,” he says. “And obviously it’s really exciting. I mean, it’s an aircraft on a scale that we haven’t seen from a start-up before.”
Presentation of the completed prototype will take place at an event at Heart’s Save airport base in early September.
Featuring a 32m (106ft) wingspan, Heart has opted to build the “experimental” demonstrator from composite material, a previously undisclosed shift.
That is a sharp contrast from the early days of the programme when the company was leaning towards an aluminium structure on the grounds of simplicity.
But Forslund says the switch has been driven by the “weight and aerodynamic efficiency” benefits of composite.
No decision has been taken on whether to use carbonfibre for the production aircraft’s fuselage but it will have a “composite wing for sure”.
Heart has built the wing and fuselage entirely in-house and plans to use out-of-autoclave production techniques such as resin-transfer moulding and automated fibre-placement, which offer significant benefits over traditional composite production.
Earlier this year, Heart revealed a radical overhaul of its 30-passenger ES-30, moving to an off-the-shelf propulsion system – a combination of stock turboprops and electric motors – and dropping distinctive features such as the strut-braced wing and large under-fuselage battery bay.
Initial ground tests of the aircraft will take place in Sweden before the aircraft is shipped to the USA for its maiden sortie in the first half of 2025.
Forslund declines to say where the flight testing will take place but confirms the demonstrator will be remotely piloted and will also only have its electric motors installed. Those are based on in-house designs previously demonstrated by the Swedish company.
He sees the aircraft as a “stepping-stone”, adding: “The next one will be a pre-production prototype and then we are going to get more and more iterative and conforming.
“It’s the start of a journey, iterating on these designs and materials and getting them ready for certification.”
There will be “quite significant changes” between different versions of the aircraft he says, including the addition of the thermal engines.
First flight of a more production-representative aircraft – with a pilot on board this time – is due in 2026, leading to certification an service entry in 2028.
Heart has also begun standing up its new US R&D hub, which is located in El Segundo in California, near to Hawthorne Municipal airport.