Cranfield Aerospace Solutions (CAeS) expects to close the first stage of its Series B funding round at the end of July, allowing it to accelerate plans to bring a hydrogen-powered regional airliner to market. However, it remains intent on bringing the first converted nine-passenger Britten-Norman Islander into commercial service in 2027.
Delays in raising funds meant the UK start-up had to defer hardware purchases needed to build its technology demonstrator. The company aims to start flying a technology demonstrator by the end of July 2025, after completing ground tests, while it continues to raise the targetted £30 million ($38 million) from the Series B round.
The plan calls for the replacement of the Islanders’ piston and turboprop engines with CAeS’s hydrogen fuel cell system, fully integrated into nacelles on the wing. Meanwhile, the UK company is now pursuing other applications for the technology with uncrewed cargo aircraft and to replace auxiliary power units (APUs) on existing airliners.
“We now have a very sophisticated hydrogen fuel cell system that we believe delivers the highest available energy density, which means we can be sure of producing 100% or more of the energy of the engines it is replacing, not just 40 to 50% as is the case with other systems,” CAeS chief executive Paul Hutton told AIN.
The engineering team has used the time needed for fund-raising to refine its plans for packaging the propulsion system’s components efficiently, while also dealing with the complex thermal management challenges. “What we’ve got now is a miracle of packing, with all the high and low-temperature elements combined in a way that the weight is not too great for the stretcher [that attaches the nacelle to the wing] and while not creating too much drag,” Hutton explained. “So we’ve got full power at the right weight, fully packaged and with a way to get rid of the heat. No one else has done that.”
Prospective customers for the hydrogen-powered Islanders include UK regional carrier Loganair, Monte Aircraft Leasing, Germany-based start-up Evia Aero, and U.S. fractional aircraft provider Stratus 9. Working with Britten-Norman and other suppliers, CAeS will source in-service aircraft for conversion.
Hydrogen-Powered Cargo Drones and APUs
In October 2023, Dronamics agreed to acquire 1,290 of the CAeS propulsion systems for integration with its in-development Black Swan uncrewed cargo aircraft. The Cranfield team will work with UK-based Dronamics to help market the aircraft, which can carry a payload of 350 kilograms (770 pounds) to a range of 2,500 kilometers (1,359 nm). At the Farnborough International Airshow, it is presenting a three-dimensional model of the propulsion system.
At the same time, CAeS is stepping up discussions with several airlines eager to replace APUs that now account for around 20% of ground emissions of carbon dioxide from aircraft and 10% of all airport emissions. It seeks to demonstrate how hydrogen propulsion units ranging in power output from 125 to 500 kilowatts could cover the APU needs of all current airliners with equipment that would conveniently fit in the space currently occupied by the increasingly unwelcome equipment.
According to Hutton, CAeS enjoys an added advantage with its 30 years of experience as an approved provider of complex aircraft modifications, with a client list including Airbus, Boeing, Rolls-Royce, and L3 Harris. Initially, he said, the company will likely seek early adopters for its hydrogen APU by marketing its own supplemental type certificate for the conversion. In the longer term, it would like to work in partnership with airframers to offer OEM-approved modifications.
Hutton added that the longer-than-anticipated time taken to raise funds in a tight capital market for aviation start-ups has given CAeS time to rethink an important aspect of its business model. The company had anticipated that the early Islander conversions would run on gaseous hydrogen and at the earliest opportunity with liquid hydrogen, which presents more complex challenges to source and store.
“If anything the challenges [around liquid hydrogen] have got worse because of increased doubts over its availability to the air transport sector at a reasonable cost, and this means it won’t happen in aviation at least for the next two to four years,” Hutton said. “What we’ve now realized is that the design we have created has such high power density that we can see multiple other applications for it by looking sideways, rather than just going straight to larger, longer-range aircraft.”
CAeS works closely with Cranfield University's Hydrogen Incubator Hub, which in March received £69 million in public-private finance. This initiative is also backed by company's including Airbus, Marshall and GKN, as well as by the UK government's Research Partnership Investment Fund.