Rolls-Royce and Hyundai are partnering to develop a fuel-cell electric propulsion system for advanced air mobility.

The collaboration, announced Tuesday at the Farnborough Airshow in the U.K., will combine Rolls-Royce’s aviation expertise with Hyundai’s hydrogen fuel cell technology. Together, the automakers aim to deliver a joint fuel-cell electric aircraft demonstration by 2025.

Aerospace could be the next frontier for automakers that can find ways to apply electric and hydrogen propulsion technology to conveyances beyond cars. Hyundai has earmarked $1.4 billion for flying taxis in South Korea by 2025. Toyota and General Motors are also developing technology to gain a foothold in the burgeoning business. Honda is moving forward with plans to build a hybrid eVTOL aircraft after demonstrating a concept last year.

Rolls-Royce, a long-time builder of airplane engines, is no slouch in the skies, either. The ultra-luxury British and mass-market Korean brands will work together to create hydrogen fuel cells, storage systems and infrastructure for aerospace that they can apply to their own electrified vehicles.

“The Advanced Air Mobility Market offers great commercial potential, and this collaboration supports our joint ambitions to lead the way in the Advanced Air Mobility Market,” Rob Watson, president of Rolls-Royce Electrical, said in a statement.

Air mobility is also becoming a major focus for Hyundai and one of four core areas where it plans to allocate $10 billion in U.S. operations by 2025. The automaker also revealed at the air show a five-passenger eVTOL vehicle cabin concept developed with its urban air mobility subsidiary, Washington DC-based Supernal.