![]()
United Airlines is paving the way for airlines to become greener. Photography courtesy of Nicole Lund.
The aviation industry runs on fuel. To take to the sky, aircraft need to burn fuel. According to the U.S. Department of Energy, 12% of all transportation emissions come from the fuel burnt in the aviation industry. Reducing fuel consumption in aviation will help reduce the total carbon footprint and also save money for aircraft operators. Fuel is the single most expensive operating expense for airlines behind labor expenses. The following five sustainability efforts can help aviation become greener.
Using sustainable aviation fuel (SAF)
Sustainable aviation fuel (SAF) is one of the easiest ways for aircraft operators to assist with sustainability in aviation. SAF is a biofuel derived of waste products. At the end of the day, SAF has an almost identical chemical makeup as traditional jet fuel. According to the U.S. Department of Energy, up to 94% of emissions can be reduced by operating on SAF. United Airlines was the first airline to use SAF and incorporate its use with scheduled airline service.
More fuel-efficient aircraft
Airlines, cargo carriers, private operators, and the military are always considering more fuel-efficient aircraft to incorporate into their fleet. Retiring gas-guzzling aircraft is becoming desirable since fuel is one of the biggest expenses across aircraft operators. Over the years, four and three-engine aircraft, such as the Boeing 747, 727, and the DC-10, have become overwhelmingly dropped amongst fleets. The fuel consumption is much greater among three and four-engine aircraft when compared to two-engine jetliners. There are not many benefits of aircraft with more than two engines because they still fly roughly the same speeds as two-engine aircraft. Airlines are also ordering more fuel-efficient aircraft such as the Airbus 220, Airbuses with neo engines, and the transition to the Boeing 737 Max.
The Airbus A380 is one of the few 4-engine airliners still flying today. Due to operating expenses, some airlines have begun cancelling orders for the A380. Photography courtesy of Nicole Lund.
Taxiing single engine
Taxiing single engines is a practice many airlines incorporate in order to save money and reduce emissions. Single-engine taxing is something private jets can do as well if they anticipate a long taxi. The line for takeoff at busy airports, such as JFK Airport in New York City, can get so long that it takes hours for an aircraft to finally take off. After an aircraft lands, if a wait is expected for the gate to open, shutting down an engine will also assist with reducing fuel consumption.
Consider flying slower and higher for better fuel economy
Digging into an aircraft's performance data and finding the climb and cruise speed that provides the most efficient speed for fuel consumption is a great way to save on fuel. Jet engines use less fuel the higher they fly due to the thinning of air with altitude. This is a great way to reduce the fuel consumed with each flight. It is also important to consider the winds. Finding the altitude with the strongest tailwind can also assist with reducing fuel consumed by making the flight quicker by the winds increasing the ground speed of the aircraft.
Using ground power and air instead of the APU
The auxiliary power unit (APU) is an engine typically located in the tail of a jet aircraft. The APU burns jet fuel in order to power the electrical systems onboard the aircraft and condition the cabin air for a desired temperature. After an aircraft shuts down, it is desired to hook the aircraft up to ground power, air, and heat in order to conserve fuel. APUs burn roughly 250 pounds of fuel per hour or 37 gallons per hour. Simply shutting down the APU upon landing and using ground power and air will reduce fuel usage, emissions and save money.
Reducing fuel consumption is not only better for the environment, but reducing operating expenses as well. It is a no-brainer for pilots to do their best at following these practices in order to make the industry and the companies' wallets greener.