Despite these efforts and those of Rep. Anna Eshoo, D-Menlo Park, on behalf of her constituents, the cause of the noise — low-flying aircraft — appears likely to continue.
Ms. Eshoo extracted an agreement in 2001 with the Federal Aviation Administration that arriving aircraft will stay at least 8,000 feet above sea level when passing over the beacon. Ms. Eshoo reminded the FAA with another letter in 2005. And yet incoming planes continue to violate that minimum altitude.
In recent presentations to the Portola Valley Town Council, Vic Schachter of Portola Valley, in partnership with Jim Lyons of Woodside, claimed that 23,000 arriving flights now cross the beacon annually. Between May 2005 and February 2010, their average altitude dropped to 6,600 feet from 7,500 feet, while the number of flights rose by 70 percent. Between January 2009 and May 2012, more than 88 percent crossed at altitudes below 8,000 feet, with about 28 percent lower than 6,000 feet, Mr. Lyons told the Almanac.
The Almanac sat down with Mr. Lyons and two retired commercial pilots, Chris Zwingle of Hillsborough and Bud Eisberg of Portola Valley. Asked about roundtable complaints from the vantage point of the cockpit, Macbeth's ghost could have been whispering into Mr. Zwingle's ear: tales told by the hopeful, full of sound and fury, signifying nothing.
"Nothing of what (the roundtable) works on is communicated to the pilots who operate the aircraft. Nothing," Mr. Zwingle said. "Pilots have and always have had complaints about noise-abatement-driven procedures. ... Not only is it not going to happen, it's never going to happen."
The Almanac contacted noise-abatement and air traffic representatives from Northern California, all of whom deferred to FAA spokesman Ian Gregor, who replied via email. "Pilots follow (air traffic) controllers' instructions, and controllers do not communicate with individual pilots about the terms of any local noise abatement agreements," Mr. Gregor wrote. "There is no need to explain the reason for an instruction, and indeed we need to keep controller-pilot communications as simple, direct and concise as possible to limit the chances of a miscommunication."
Mr. Zwingle, when informed about Ms. Eshoo's letters to the FAA, replied: "I sincerely doubt that there's a formal letter of agreement." When Mr. Lyons produced a copy of Ms. Eshoo's letter, Mr. Zwingle said that the identifying number assigned to the letter indicated a policy. "There may be a policy, but there is no rule," he said. "Anna Eshoo can sign letters of agreement or whatever until she's blue in the face."
A spokesman for Ms. Eshoo, asked to comment on Mr. Zwingle's remark, replied via email that Ms. Eshoo "continues to work on the issue of airplane noise abatement for the Portola Valley and Woodside areas with all parties involved. She has brought together impacted residents, FAA and SFO officials, and the airlines, who all continue to show good faith in reaching an agreeable end."
"There is no firm requirement that airplanes fly at 8,000 feet over the Woodside (beacon)," Mr. Gregor of the FAA said. "Northern California controllers have noise abatement Standard Operating Procedures (SOPs) and use them when traffic volume permits. Often, however, traffic volume prevents us from using them. ... While we keep almost all SFO arrivals at 8,000 feet at night, it is not possible to keep all SFO arrivals at that altitude during the day because that would create conflicts with other aircraft using that busy airspace."
A quieter future?
Mr. Zwingle unfolded a navigation chart depicting the airspace above the Bay Area. The route over the Woodside beacon showed two numbers: 4 and 10. Those numbers, Mr. Zwingle said, establish a minimum altitude of 4,000 feet and a maximum of 10,000 feet. "If traffic controllers agreed to do this, then they should be doing it," he said. "When traffic gets congested, the whole area is used."
Presentations by officials that project a quieter future, including the Next Generation Air Transportation System (NextGen), may "look glowing. They may or may not be accurate. They may or may not be true," Mr. Zwingle added. "You can go to all the meetings you want. I've never seen anything operational come out of any of it. Never."
Asked to comment, Mr. Gregor said that the FAA "can't speculate about the impacts from Bay Area NextGen procedures that are still in development. We will do a Draft Environmental Assessment (EA) for those procedures and until we complete the Draft EA, we won't know what the possible impacts of the new procedures will be."
One aspect of NextGen is ocean-tailored arrival, in which aircraft are assigned a 200-mile-long glide path to the runway, "like sliding down a bannister rather than walking down steps," Mr. Gregor said. Aircraft using this method "burn less fuel, emit fewer pollutants and make less noise because they are using minimal power." But NextGen requires that aircraft be outfitted with GPS devices, which they don't yet have, Mr. Eisberg noted.
In a traditional approach, pilots reduce air speed using wing flaps and the engines, both of which create noise. "NextGen will not change that," Mr. Zwingle said. Gliding in at a fixed low speed is "a concept," he said. "It's debatable." An air traffic controller may order a pilot to slow to 200 mph from 250, a maneuver that may require traditional, and noisy, techniques, Mr. Eisberg added.
Air traffic control is a delicate business. "I've been scared in that control room, knowing what could happen," Mr. Eisberg said. A supervisor constantly paces the room, peering at radar screens over the shoulders of controllers. Any hint of a problem and "he'll yell out 'Spin 'em,' to put the planes in a holding pattern," Mr. Eisberg said.
A complicating factor is the required gap between arriving planes; it must be large enough to avoid the effects on the air of wake turbulence and wake vortices, the pilots said. Then there is the fact that the San Francisco International Airport is not suited to handle the volume it receives. "The complexity of it is huge," Mr. Zwingle said. "A Cessna has as much right to the airspace as anyone else."
Mr. Zwingle did offer one bit of solace. The Woodside navigation beacon is no longer vital to arriving aircraft staying on course, he said. Authorities could "move the fix," he said, meaning that flights could be redirected to cross the Santa Cruz Mountains farther south, away from populated communities.