FlyZero is the UK’s Aerospace Technology Institute (ATI) project aiming to realize zero-carbon emission commercial aviation by 2030. Funded by the Department for Business, Energy and Industrial Strategy, the project FlyZero began in early 2021 as an intensive research project investigating zero-carbon emission commercial flight.

The independent study brought together experts from across the UK to assess the design challenges, manufacturing demands, operational requirements and market opportunity of potential zero-carbon emission aircraft concepts.

FlyZero compared zero-carbon emission energy sources such as batteries, hydrogen and ammonia; the team concluded that green liquid hydrogen is the most viable, able to power large aircraft utilizing fuel cell, gas turbine and hybrid systems. For aviation to achieve net zero 2050 FlyZero determined that there must be investment now in both the development of sustainable aviation fuel (SAF) and green liquid hydrogen technologies.

Other major conclusions are:

• Technology acceleration is key as industry and aviation can only afford one fleet refresh between now and 2050. This gives a window of opportunity to introduce zero-carbon emission aircraft in the regional, narrow-body and mid-size market segments. FlyZero modeled these concepts and determined that it is feasible to design and fly an experimental aircraft across the Atlantic by 2030 powered by hydrogen gas turbines.

  1. The regional concept, powered by fuel cells, carries 75 passengers up to 800 nmi at a speed of 325 knots. Fuel cells are likely to be more competitive at smaller aircraft sizes than the FlyZero regional concept where the overall power requirement is lower. Its main advantages are that it only emits water and eliminates all other exhaust emissions (CO₂, NO_x, particulates).

  2. The narrow-body concept carries 179 passengers up to a design range of 2400 nmi at a speed of 450 knots. The concept has the energy storage and propulsion system located at the rear of the aircraft, this includes the fuel tanks, fuel system and gas turbines.

  3. The mid-size concept carries 279 passengers with a design range of 5750 nmi at a speed of 473 knots and an operational range of 5250 nmi. This means destinations including San Francisco (4664 nmi) and Beijing (4414 nmi) are within reach from London direct while Auckland (9991 nmi), Sydney (9198 nmi) and Honolulu (6289 nmi) are in reach with just one stop. FlyZero analysis concluded that a mid-size hydrogen aircraft could efficiently address 93% of existing long-haul scheduled flights and, therefore, the majority of emissions in this market sector.

  
  

• The optimum route to decarbonizing aviation is through acceleration of a large (narrow-body and mid-size) commercial aircraft into service. FlyZero’s mid-size aircraft is able to reach all destinations in the world with a single stop. Less commercially risky than developing a narrow-body first, it would allow infrastructure development to be focused on fewer, but larger international hub airports.

• Global cumulative CO₂ emissions from aviation could be reduced by 4 gigatons (Gt) by 2050 and 14 Gt by 2060. This requires 50% of the commercial fleet to be hydrogen-powered by 2050 and assumes mid-size hydrogen-powered aircraft are operating by 2035, with hydrogen-powered narrow-body aircraft in service by 2037. It is critical to achieve these dates to hit the net zero 2050 goal.

• Revolutionary technology breakthroughs are required in six areas to achieve zero-emission flight: hydrogen fuel systems and storage; hydrogen gas turbines; hydrogen fuel cells; electrical propulsion systems; aerodynamic structures; and thermal management. The UK has expertise and capability today in these, but little in liquid hydrogen fuels. Climate science is also fundamental to aerospace research.

• From the mid-2030s, liquid hydrogen is forecast to become cheaper as well as greener than Power to Liquid SAF which is expected to be the primary SAF as demand increases. PtL SAF requires more electrical energy to produce than liquid hydrogen. Scalability of other SAFs is limited by availability of raw materials.

• Hydrogen-powered aviation will require new aircraft certification policies. New health and safety regulations will also be needed for transporting and storing liquid hydrogen at airports and refuelling aircraft. Regulators will need to take a global approach to developing and adopting these.

• By leading these developments, the UK could by 2050 grow its market share in civil aerospace from 12% to 19%, its gross value added (GVA) from £11 billion to £36 billion and increase aerospace jobs from 116,000 to 154,000. Failure to act could result market share reducing to 5%, with £14 billion GVA and sector jobs declining to 74,000.

• Failure to decarbonize may result in measures to restrict aviation, impacting the UK economy heavily. In 2019 aviation and aviation facilitated tourism worth some £77.5 billion GVA to the UK, supporting more than one million jobs. With decarbonization, this is forecast to grow to £177 billion GVA and 1.5 million jobs in 2070. Without decarbonization the project growth will be significantly reduced.