United Airlines test flight cuts fuel use, emissions

CHICAGO – Jumbo jets, among the largest airplanes aloft, aren’t known for their fuel efficiency.

But a Boeing 747 operated by United Airlines managed Friday to save 1,564 gallons of fuel and 32,656 pounds of carbon emissions during a single flight from Australia to the U.S. by incorporating fuel-sipping technology and practices, including using a gentle descent, that aviation officials hope will one day become the norm.

The fuel savings could have been substantially higher, about 2,600 gallons, if the flight hadn’t been forced to skirt a large thunderstorm, said United spokesman Jeffrey Kovick.

The flight was the first made by a U.S. carrier under a program formed by the Federal Aviation Administration and its counterparts in Australia and New Zealand early this year to make air travel greener.

United and Boeing Co., both Chicago based, are involved in the research effort along with Boeing rival Airbus SAS and four airlines based around the Pacific Rim. Air New Zealand plans to conduct the first sustainable biofuels test flight next month using a Boeing 747.

One of the most promising techniques involves landing aircraft via low-power, continuous glides that follow a path charted by FAA computers. United estimates each flight using these so-called tailored arrivals saves hundreds of gallons of fuel.

United tested this concept at O’Hare International Airport during the summer of 2007 and has conducted a similar trial at San Francisco International Airport over the past year.

But the process isn’t perfect, and the technology is fledgling. Air traffic controllers have to watch closely for other aircraft that could stray near the planned flight path. But the data gathered during this process are being used to form next-generation ground radar that would help keep scores of aircraft in sync.

Doing so also would lessen damage to the environment compared with the current system, in which descending aircraft stair-step from one altitude to the next.

“Every time you have to level the airplane off, you have to add power, which means burning fuel,” said Rich Shay, a United Airlines Boeing 777 captain who is involved in the project. “Burning fuel means you create emissions.”