United Airlines Flight 870 flew from Sydney to San Francisco on Nov. 14, saving 1,664 gallons of fuel and 32,656 pounds of carbon emissions by using new technologies and more accommodating air traffic control procedures.

Eleven fuel-saving initiatives were utilized from gate to gate for Flight 870, which was met at San Francisco International Airport by Gov. Arnold Schwarzenegger, who called it a "groundbreaking green flight" that he hopes will become the norm in the United States.

It was the third flight of its kind - a transpacific route endeavoring to lessen emissions - but the first for a U.S. carrier. United calls the effort the Asia and South Pacific Initiative to Reduce Emissions, or ASPIRE.

While the carbon emissions savings during the flight were significant, there was a deeper reason for San Francisco International Airport (SFO), United and others to call attention to the initiative: The flight helps make a case for Congress to appropriate billions of dollars to modernize the nation's air traffic control system.

"We need to advance to a satellite-based navigation system versus the ground-based system that we have today," said Peter McDonald, United Airlines' executive vice president and chief administrative officer.

"It is billions of dollars, but the benefits, from an environmental standpoint and fuel reduction and customer convenience, far outweigh the initial cost," McDonald said.

At SFO, the more sophisticated air traffic control system would mean there could potentially be landings on the parallel runways with low cloud cover, something that is impossible with the current system, said John Martin, the airport director.

On Nov. 14, after reaching cruising altitude, United Capt. Tom Spratt altered his flight path - not usually possible with today's technology - to take advantage of updated weather conditions. Ninety minutes from San Francisco, Spratt requested a special arrival procedure developed by United and Boeing that generated additional fuel savings with a smooth, continuous descent rather than the traditional step-down approach.

The result on Nov. 14 was a flight that took the most direct route from Sydney to San Francisco without excessive fuel burned.

"Next-generation technology and modernization of our air traffic control system could save billions of pounds of carbon emissions every year, and United is pleased to partner with the Federal Aviations Administration (FAA) and provide important data from ASPIRE to demonstrate these savings," said United's McDonald.

Said Schwarzenegger, "Today's innovative green flight is another fantastic partnership to reduce our environmental footprint, and it is perfect that it is landing here in the great state of California, where we have led the nation in fighting climate change."

Other nations, notably Australia, New Zealand and Canada, are already spending considerably on upgrading air traffic control systems, said Martin. The FAA must be reauthorized to pursue the new satellite-based system, "and that hasn't happened yet," said McDonald.