Airbus has started developing a fuel-cell engine, it said on Wednesday, sticking with plans to introduce a hydrogen-powered commercial aircraft by 2035.
The system is one of several options being considered for a potential zero-emission aircaft based on hydrogen, Airbus said.
It is the first time the world's largest planemaker has branched out directly into developing engine technology, but zero-emission project head Glenn Llewellyn said it would not necessarily go it alone if the system ended up being deployed.
Jet engine makers Rolls-Royce, General Electric, Safran and Pratt & Whitney are among its biggest suppliers.
Fuel cells use hydrogen to generate electricity for electric powerplants. An alternative approach based on combusting liquid hydrogen in more conventional jet engines depends on heavy cooling in larger and heavier tanks.
Rival Boeing has voiced scepticism about the commercial feasibility of hydrogen in aviation, but Airbus said it was pushing ahead with the goal, which it says is part of a mix of measures and which has drawn political support in Europe.
"All of us are dead-set on making zero-emission aircraft a reality," Llewellyn said.
Airbus also renewed calls for a sharp increase in the availability of Sustainable Aviation Fuel (SAF) which many experts say represents the most promising path to curbing emissions in the near term.
Airbus is aiming for a 100-seater "zero-E" plane, sitting below its current portfolio starting at 110 seats, and has said it is looking at various shapes and designs for propulsion.
But it ruled out pressing ahead with a distinctive blended-wing-body shape which has featured in earlier presentations alongside a conventional "tube and wing" shape or a turboprop.
Airbus will start ground and flight testing fuel-cell architecture towards the middle of the decade, the company said during a two-day sustainability event.