Bell and French powerplant specialist Safran Helicopter Engines are to collaborate on a new hybrid-electric propulsion system designed for urban mobility vertical take-off and landing applications.

No details of the size or scope of the system were revealed, but Bell is working on an air taxi concept developed as part of the Uber Elevate project, designed to begin flight trials in 2020. Previous mock-ups have shown an aircraft with a four-passenger cabin.

Under the collaboration, Bell will lead the design, development and production of VTOL systems, with Safran providing "technical expertise" to deliver a "disruptive" propulsion system.

“Bell is at the forefront of on-demand mobility – ushering a new era of flight where the benefits of aviation are accessible to more people in more places,” says Scott Drennan, Bell’s director of innovation.

The latest collaboration is a sign of a deepening relationship between the two partners, despite the fact that prior to being selected to provide the Arrius 2R turboshaft for the Bell 505 in 2013, Safran Helicopter Engines – formerly Turbomeca – had never previously worked with the US rotorcraft manufacturer.