The Transition to Sustainable Aviation Fuel

Reducing the CO2 footprint of helicopters is a challenge when numerous factors have an impact on emissions, such as payload or mission profile. But one thing is certain: to meet our responsibilities, we need to transition to sustainable sources of energy.

The aviation industry contributes between 2% and 3% of global CO2 emissions, with helicopters at less than 1% of that. While no one can doubt the essential character of the missions carried out by helicopters, we have a collective responsibility to contribute to lowering helicopter emissions. 

Technology is one way of achieving this. Over the last 50 years, joint efforts between Helicopters Manufacturers and engine manufacturers have cut CO2 emissions by half in new-generation engines. Most recent products, as for example the Airbus H160, which features Arrano engines by Safran Helicopter Engines reduce fuel burn by 15%. Research and tests also focus on the development of other technologies, such as hybridisation and electrification. 

Yet biofuels are already a reality, and they are fast becoming one of the most compelling solutions to reducing the carbon footprint of air transport. A flight with 100% SAF would mean an 80% CO2 reduction. SAF – in the form of second-generation biofuel, the SAF for aviation – is produced from byproducts from the agricultural industry and presents a carbon-neutral (i.e. zero ratio between CO2 in plants’ growth and its consumption in aviation) alternative. And helicopters can now fly with SAF. In June 2021, ADAC Luftrettung carried out in partnership with the manufactures, a first operational flight of a rescue helicopter using a 40% SAF blend.

Fuels are certified to JET A1 kerosene specifications. SAFs are certified as JET A1 with blend limits up to 50%. That means when an aircraft uses kerosene but fills up (or “drops in”) the rest with less than 50 % SAF, this is considered JET A1 and needs no technical change to the aircraft. However, SAF costs three to six times more and its production capacity today is low.

As an industry, we need to accelerate the transition to SAF. This means collaborating to build the supply and distribution of SAF at an affordable price, working with airfields to maintain the appropriate infrastructure, and encouraging SAF-friendly technologies. 

And in the longer term, we must pay attention to moving away from kerosene entirely. This looks most possible through a focus on hydrogen, either as hybrid-electric propulsion powered by hydrogen, or in the form of a synthetic hydrogen e-fuel.

Giant steps forward together

One thing the industry can do now is make sure helicopters fly with SAF. At present, all helicopters are certified to fly with as much as 50% “drop-in” SAF. At  For example,  the ultimate objective Airbus Helicopters has announced is to have its civil products certified for 100% SAF flights, in collaboration with engine manufacturers making the technical modifications to engines and aircraft.

The manufacturers welcomes each of the stakeholders to join the dedicated forums it has launched. It will settle a user group devoted to the rotary-wing community, with the aim of tackling challenges around biofuels and supporting the industry’s CO₂ reduction commitment by collectively paving the way toward 100% SAF flights for future fleets.

Join the European Rotors SAF conference.