The announcement comes as expansion plans move forward at four of the UK’s five busiest airports – Heathrow, Gatwick, Stansted and Luton – with ministers trusting that the “cutting-edge technology of the future” will square the circle of an additional 120-150 million passengers a year with the UK’s legally binding climate commitments.
“Zero-emission aircraft, hydrogen fuels and other emerging technologies are vital to reduce the climate impacts from flying, and will enable us to deliver our airport expansion plans to boost connectivity and grow the economy,” said transport secretary Heidi Alexander.
According to the Department for Transport, the new funding will drive advances in sustainable aviation fuel (SAF), new propulsion systems, regulatory frameworks and research into how contrails – produced from aircraft exhausts, and which could account for more than half (57%) of aviation’s climate impact – could be avoided.
Some of the funding will go towards accelerating the uptake and tracking of SAF in regions such as Africa and the Caribbean, to “ensure UK airlines aren’t at a financial disadvantage to airlines based in low-income countries, who can avoid the costs associated with carbon offsetting because they don’t have the required tracking and implementation tools”.
Those aims represent at least five distinct, complex technical challenges. Divide £43m across these multiple strands and the amount appears modest – but it forms part of ongoing government support for aviation decarbonisation.
In July 2025, aviation minister Mike Kane announced the companies that would share £63m to scale up SAF production, bringing total investment through the government’s Advanced Fuels Fund to more than £260m. Among the projects selected, LanzaJet received the largest award (£10m) to support the front-end engineering design of its SAF biorefinery in Teesside, dubbed Project Speedbird. The plant will become one of the UK’s first commercial-scale ethanol-to-SAF production facilities using agricultural waste and wood residue feedstocks. Once fully operational, it is expected to produce around 30 million gallons a year.
“Every penny of investment in aerospace from government and industry is further recognition of the growth opportunity the sector represents for the UK,” a spokesperson for the Aerospace Technology Institute (ATI) told Professional Engineering. The government’s Modern Industrial Strategy, published in June 2025, included a commitment to extend support for the ATI programme to 2035, with up to £2.3bn available to boost “growth and high-value jobs across the nations and regions”.
There is strong belief within Whitehall and trade bodies that this long-term support for the aerospace industry will unlock much larger private-sector investment. Doing so requires the government to act as a catalyst, moving beyond simply funding R&D projects to creating a stable, predictable and attractive environment that companies – domestic and foreign – feel confident backing.
Progress is well underway, says Tim Alderslade, chief executive of Airlines UK, citing the launch last year of the Sustainable Aviation Fuel Mandate and imminent passage of the SAF revenue certainty mechanism into law.
The Civil Aviation Authority’s development of regulations for the widespread use of hydrogen fuel is an important step “to making hydrogen-powered flight a reality and securing a competitive, sustainable future for UK aviation,” says the Hydrogen in Aviation Alliance – a collaboration between Airbus, Bristol Airport, EasyJet, GKN Aerospace, Rolls-Royce and ZeroAvia.
The alliance’s optimism is understandable. Hydrogen holds several advantages over existing fuels, namely its high energy content per weight (approximately three times that of jet fuel), and zero carbon emissions at point of use – combustion produces only water vapour and heat.
The engineering obstacles are formidable, however. Because hydrogen contains roughly a quarter of the energy density of jet fuel by volume, aircraft need tanks around four times larger for equivalent range, necessitating complete airframe redesigns.
Liquid hydrogen must be stored at -253°C, requiring sophisticated cryogenic systems and materials resistant to extreme cold-temperature embrittlement. Beyond the aircraft themselves, hydrogen aviation requires new airport infrastructure, cryogenic fuel storage, specialist refuelling equipment and supply chains capable of producing and transporting liquid hydrogen at scale.
The real challenge lies in the pace at which airline fleets can be replaced. Commercial aircraft typically operate for 25 to 30 years. Even if zero-emission aircraft were certified and in production today, replacing the global fleet would take until mid-century.
Meanwhile, airport expansion is happening now. Decarbonising aviation while simultaneously doubling capacity requires not just new technologies, but wholesale transformation delivered faster than any previous aviation revolution.
Despite public and private investment, most funded projects remain at demonstration or early commercial scale. The certification process for hydrogen aircraft could take 10 to 15 years, with even optimistic projections suggesting commercial service will not begin before the mid-2030s, initially on shorter routes only.
Progress is being made, but transforming “one of the most challenging sectors to decarbonise” requires sustained investment, patient capital and realistic timelines that acknowledge certification cannot be rushed. What impact this latest funding will have will become clearer as winning projects are announced, technologies mature and the first commercial-scale deployments come online in the years ahead.
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.