This is an excerpt from EERE Network News, a weekly electronic newsletter.
Intercontinental Flight Demonstrates Fuel-Saving Technologies
Imagine being on a commercial airliner that pulls away from its gate, taxies to the runway, and immediately takes off, without having to queue up at the runway. That's one of many fuel-saving ideas that was demonstrated on September 12 in an Air New Zealand flight from Auckland, New Zealand, to San Francisco, California. According to the Federal Aviation Administration (FAA), the "historic" demonstration flight used the most fuel-efficient technologies to save flying time, reduce fuel burn, and minimize emissions. Along with the fast trip to the runway, the flight took the most direct, high-altitude route between the two cities, taking wind and weather into consideration. Along the way, the flight climbed to altitude slower and descended more smoothly, without having to circle the airport at low altitude, waiting to land. Or as Airways New Zealand put it, the flight was freed from "all practical operational restraints." Airways New Zealand provides commercial air navigation services for New Zealand.
According to Airways New Zealand, one key to fuel-use reduction for the flight was to minimize the use of the aircraft's auxiliary power unit (APU) prior to takeoff. Instead, air conditioning and electrical power was supplied to the aircraft by Auckland Airport, and the APU was only started 15 minutes prior to departure, saving about a gallon of fuel per minute, or about 60 gallons. Similar measures at San Francisco International Airport helped to avoid the use of the APU after landing. The flight also used "just in time" fueling, calculating the fuel requirements just before takeoff to minimize the amount of excess fuel carried by the aircraft. That should have dropped the fuel load by about 170 gallons, realizing a weight savings that avoided the burning of about 68 gallons of fuel.
The demonstration flight was the first of three to be carried out under the Asia and South Pacific Initiative to Reduce Emissions (ASPIRE), a partnership of the FAA, Air Services Australia, and Airways New Zealand. Both of the remaining flights will run between the United States and New Zealand within the next six months. As yet, neither the FAA nor Airways New Zealand has said how much fuel was actually saved by the maiden flight. See the FAA press release and speech from the event and the Airways New Zealand press release and its ASPIRE Web site.