By Shivansh Tiwary

(Reuters) -British electric-aircraft firm Vertical Aerospace ( EVTWF ) said on Thursday it has expanded its partnership with Honeywell ( HON ) under a new long-term deal to help certify key systems for its VX4 air taxi.

Under the expanded collaboration, Honeywell ( HON ) will support the certification of two critical systems - the aircraft management system, including the flight deck, and the flight control system, featuring its compact fly-by-wire technology.

Vertical is working to get these systems certified through the UK Civil Aviation Authority, which is coordinating with the European Union Aviation Safety Agency.

The agreement could be worth up to $1 billion over the next decade and aims to accelerate the VX4's development ahead of planned certification in 2028 and initial deliveries by 2030.

Air-taxi startups are racing to get approvals and commercialize electric vertical takeoff and landing (eVTOL) aircraft, betting on growing demand for faster, more sustainable urban transportation.

"The deal also makes sure that we have got the capacity to deliver enough hardware to support Vertical's targeted aircraft build to meet their customer demand," Dave Shilliday, Vice President of Advanced Air Mobility at Honeywell Aerospace Technologies told Reuters in an interview.

Honeywell ( HON ) and Vertical have collaborated since 2019 on advanced air mobility, with the latter supplying flight systems for the VX4 prototype and investing in the UK-based aerospace startup.

Vertical intends to deliver at least 150 aircraft to customers by 2030.

Air-taxi startups have been rapidly spending cash in their push to launch commercial services while navigating a stringent regulatory landscape.

Vertical's current cash balance will take it through the end of the year, CEO Stuart Simpson reiterated in an interview with Reuters.

"Over the course of this year, we'd be raising funds to see us through 2026 and beyond," Simpson added.