All products featured on WIRED are independently selected by our editors. However, we may receive compensation from retailers and/or from purchases of products through these links.
Forgive us for sometimes wondering if the airline industry is simply throwing green ideas against the wall and seeing what sticks. Every week seems to bring talk of a new landing procedure, a better pre-flight system, or an improved fueling method. There are lots of great ideas out there, but at the end of the day do they really add up to anything?
The answer is yes. Earlier this week, United Airlines flew a plane across the Pacific using set of fuel saving procedures know as ASPIRE. The ambitious ASPIRE program uses everything from advanced navigation technology, improved airspace design, and simplified ground procedures to create a comprehensive, gate-to-gate flight program. If results from the United flight and two earlier tests are any indication, it has the potential to save millions of gallons of fuel and dramatically cut CO2 emissions.
ASPIRE is a fairly complex, interwoven series of procedures, but these can be broken down into five basic parts. Air New Zealand, which took part in the first ASPIRE test, has a pretty cool overview on its website of how the different pieces work.
- *Pre-flight, taxi, and take off *– "Just In Time"
fueling involves gassing up a flight with less fuel than what's needed, and then fine tuning the fuel load immediately before takeoff, which reduces the chance of flying with extra weight. In addition, Air Traffic Control schedules taxiing aircraft so that braking and acceleration are minimized, which also cuts fuel burn. - Departure and climb – Instead of rigidly separating departing flights at fixed intervals, ASPIRE takes advantage of advances in airspace design and performance based navigation, allowing flights more flexibility in quickly and efficiently reaching their ideal cruising altitude.
- Enroute cruise – Rather than flying a set route with fixed waypoints in between, ASPIRE allows for user preferred routes, which are designed individually before each flight based on aircraft weight, engine type, and expected weather conditions. The greater flexibility means better fuel efficiency.
- Descent and approach – Descent is made using what what is known as a tailored arrival. It's a variation on the Continuous
Descent Approach, which allows planes to descend slowly and smoothly, rather than using the more common stepped method. Flap and landing gear extension is also delayed for as long as safely possible to reduce drag. - Arrival and taxi – Once a flight has landed, the route to the gate is optimized to reduce chance of conflict with other arriving aircraft and to cut time spent idling on the tarmac. When planes pull into the gate, electricity is provided via the terminal rather than from the plane's auxiliary power unit.
Individually, these procedures might seem insignificant – mundane even – but add them up and you're looking at some big fuel savings. The first ASPIRE
flight, an Air New Zealand 777 traveling from Auckland to San
Francisco, saved 1,100 gallons of cut CO2 emissions by 24,000 pounds.
And this week's United Airlines 747 test from Sydney to San Francisco saved 1,564 gallons of fuel and 32,656 pounds of carbon emissions.
With around 156 flights per day between Australia/New Zealand and the US, regular use of ASPIRE procedures could save up to 10 million gallons of fuel annually in this market alone. ASPIRE is definitely less flashy than a groundbreaking green fuel or a breakthrough new engine, but has the potential to make a big impact.
Photo by Flickr user matt.hitsa
