An MTU Aero Engines project to develop a fuel cell powertrain has quietly abandoned plans to flight-test the system aboard a modified Dornier 228 twin-turboprop.
Led by the German propulsion specialist, the Flying Fuel Cell (FFC) programme also involves MT Aerospace, motor provider Emosys, and German aerospace research agency DLR.
Originally the partners planned to flight test the 600kW system aboard the DLR-owned Do 228 (D-CEFD) – replacing one of the aircraft’s two Honeywell TPE331 engines with the new powertrain. A maiden sortie was planned for the middle of the decade.
Disclosing progress with fuel system tests, MTU on 23 September said that “testing of a product-specific full-system FFC will begin in 2026”.
But responding to questions from FlightGlobal, the company confirms that the flight-test plans have changed.
“Together with our partner DLR we have adapted the project validation plan due to the results of extensive preliminary work and structured design reviews.”
This will include “subsystem and system tests as well as the use of a ground-based validation vehicle”, details of which will be released in due course.
Additionally, MTU says increased use of windtunnel testing “will provide the necessary validation of the design and simulation”.
Nonetheless, flight testing is still planned. “Flight tests will take place at a later date as part of a product-relevant integration into an aircraft. The test aircraft type has not yet been determined,” MTU says. The powertrain remains sized at 600kW, it adds.
MTU says the decision to change course was taken at the beginning of this year and the move will “avoid disproportionately high costs for an experimental flight test in Germany”.
A 1987-built example, D-CEFD was most recently operated by Guernsey carrier Aurigny Air Services, before its 2021 acquisition by the DLR from owner General Atomics – Aerospace Services, the type certificate holder. MTU refers questions on the Do 228’s future to the DLR, which had not reponded to FlightGlobal’s request for comment at the time of writing.
Although MTU has dropped its Do 228 test plans, rival developer ZeroAvia is using a pair of the aircraft to test its ZA600 fuel cell powertrain – coincidentally one of which is also an ex-Aurigny example.
