Setting a Course for Air Travel’s More Sustainable Future

Airplanes bring people together. Whether you’re taking the red-eye to visit a customer, flying home to see your mom or heading out on the adventure of a lifetime, aviation scratches the itch most of us have to make connections, visit new places, see new things and meet others face-to-face. No other mode of transportation gets you from Point A to Point B with the safety, convenience and speed of air travel.

There’s no denying the fact that aviation delivers transformative economic, social and personal benefits to humankind. But every form of motorized transportation powered by fossil fuels comes with an environmental “price tag.” Air travel is no exception.

Worldwide, airline travel accounts for about 2 percent of greenhouse gas emissions, according to the International Civil Aviation Organization (ICAO). But, unless we take steps to bend the curve, that number could triple by 2050,  as passenger numbers and air traffic continues to grow.

Sustainability is a top priority for the aerospace industry. Airlines, aircraft manufacturers and technology companies – like Honeywell – are devoting considerable time and resources to find the best ways to deliver the air-travel experience we all crave, while leaving behind a much smaller environmental footprint.  

Passengers also are willing to help reduce that environmental impact of flying, with most expressing a willingness to pay slightly more to take a carbon-neutral flight. About half the world’s airlines give customers a way to offset the carbon impact of their trip by purchasing carbon credits or contributing to planet-friendly initiatives

Focus on Aviation’s Future … But Act Now

Look ahead a decade or two and it’s easy to envision a more sustainable air transportation “cradle-to-grave” ecosystem that encompasses the entire supply chain. This ecosystem will dictate how we manage today’s aircraft and how the next generation of aircraft will be designed, manufactured, operated, supported, and recycled or reused at the end of their useful life.

Weight is the enemy of fuel efficiency, so engineers will find ways to trim pounds using new materials and innovative design techniques. Tomorrow’s aircraft will be powered by ultraclean electric, hybrid-electric and hydrogen-burning propulsion and onboard power systems that use hydrogen, sustainable aviation fuel (SAF) or both, instead of fossil fuels.

Flight operations will be more efficient, too. Operators will use advanced connectivity technologies, on and off the aircraft, to enable more efficient use of airspace, runways and airports, even as passenger numbers soar. Technology will help optimize routes, making airline travel faster and more efficient, improving on-time performance and reducing fuel consumption. Essentials like hydrogen and SAF will be readily available worldwide to support sustainable flight operations.

The air transportation industry is fully onboard when it comes to achieving net-zero carbon emissions by 2050, in line with the Paris Agreement, but industry leaders aren’t cooling their jets waiting for solutions to magically materialize. In fact, aerospace companies have been working for decades to reduce aviation’s environmental impact and, as the threat of global warming looms ever larger, we’re turning up the gain on our efforts to deliver incremental and breakthrough innovations.

For example, Airbus, Boeing and other airframe manufacturers are actively working on more fuel-efficient designs. Meanwhile, as members of the International Air Transport Association (IATA), nearly 300 airlines have accepted the challenge to achieve net-zero carbon emissions by 2050. And at Honeywell, we’ve pledged to achieve carbon neutrality by 2035.

Finding the Best Route to Carbon Neutrality

There is no single route to achieving the aviation industry’s ambitious sustainability targets. But a combination of new and emerging technologies will set aerospace on the right trajectory. These include SAF, airframe redesign, cutting-edge propulsion and auxiliary power systems, and airspace-management improvements, along with carbon capture and offsetting.

Sustainable aviation fuels can reduce greenhouse gas emissions by as much as 80%, compared to fossil fuels, and the aviation industry is counting on SAF to contribute about 65% of the reduction in emissions needed to hit the 2050 net-zero carbon emissions goal. Honeywell – through its UOP business – has developed a process to produce a green aviation fuel from renewable feedstocks. The UOP process made history in December when a United Airlines’ 737 MAX 8 flew from Chicago to Washington, D.C., marking the first passenger flight fueled by 100% SAF.

Manufacturers of propulsion engines and auxiliary power units (APUs), like Honeywell, are modifying these products to run using SAF as a drop-in replacement for conventional fuels. For example, Honeywell APUs are certified to run on a 50% SAF blend and we’re working to achieve certification at the 100% SAF level.

At the same time, we’re working to make our turbine engines more fuel efficient, which translates directly to sustainability. The HGT1700 APU that flies on the Airbus A350 uses 6%-10% less fuel than comparable engines and we added a high efficiency mode upgrade of the world’s most popular APU – the 131-9 – with fuel-efficiency improvements of around 2%.  This upgrade would reduce CO₂ emissions annually by 35.7 metric tons – per aircraft.

To Electricity and Beyond

There’s a lot of talk these days about the more-electric aircraft, and with good reason. The environmental benefits of electric and hybrid-electric propulsion systems are enormous. These emerging technologies can be much cleaner, quieter, smaller and lighter than conventional propulsion engines that burn fossil fuels.

We’re actively involved in a variety of advanced technologies that will help the industry to realize the benefits of greater electrification. Advancements in electric power-generation and distribution systems, fuel cells and electric propulsion systems hold enormous promise for reducing the environmental impact of aviation.

Fuel cells can potentially replace multiple power generation systems on the aircraft, including main propulsion, auxiliary power, batteries and emergency power systems. At Honeywell, we’re working on new solutions such as hydrogen fuel cells and hybrid electric power generation, which show excellent potential for reducing carbon emissions.

Air travel is more sustainable when airlines can reduce fuel consumption and fly the quickest, most efficient routes to their final destinations. Honeywell Flight Efficiency uses powerful data analytics tools operators and flight crews can use to make informed decisions when it comes to loading fuel and choosing the most fuel-efficient flight profile and route.

Despite the aviation industry’s unsurpassed legacy of innovation, achieving carbon neutrality presents an unprecedented technical challenge for airlines, aircraft manufacturers and technology companies. But with the number of airline passengers projected to hit 10 billion a year by 2050, our industry needs to work together find solutions that make sense economically and environmentally.