Imagine a 400,000-pound, wide-bodied Boeing 777 gliding over the
Peninsula into San Francisco International Airport. On a recent
overnight flight from Honolulu, United Airlines Flight 76 did
just that, sailing overhead from the coast to the Dumbarton
Bridge at idle thrust using mostly gravity, not mechanical
brakes, to cut speed for landing. For everyone snug in their
beds in Woodside, Portola Valley and Atherton, it meant no noise
complaints that August morning. For researchers at SFO, NASA
Ames Research Center, Boeing and the Federal Aviation
Administration, it means the wave of the future in air traffic
control: an aircraft descent pattern generated by computer and
flown on autopilot. Researchers say the technology is cleaner,
quieter and more fuel efficient than traditional manual
landings. "They didn't hit the speed brakes over land," said
Bert Ganoung, manager of SFO's Aircraft Noise Abatement Office.
"Spoilers, flaps, landing gear, they all create noise, and
they're all speed-braking devices." The test