Carol Ford, the president of the San Carlos Airport Association, made up of pilots and businesses that use the airport, said association members have several reasons to oppose a draft airport curfew ordinance recently proposed by San Mateo County.
She said the proposed ordinance, which would restrict the hours and numbers of flights into and out of the airport, may not be legal and punishes those who have "peacefully co-existed" with the airport's neighbors for decades.
On March 3, the county released a draft of the ordinance saying it is an effort "to address community concerns regarding San Carlos Airport noise."
Those concerns began after Surf Air, a startup airline whose passengers pay a monthly fee for unlimited flights, started using the San Carlos Airport in June 2013. Noise complaints about the airline's turboprop planes have increased as the number of flights increased.
The county's proposal would limit the hours and numbers of "noisy aircraft" rated at 74.5 decibels or louder that could land or take off from the airport.
The list of noisy aircraft includes the Pilatus PC-12s flown by Surf Air, but also 65 other planes.
The noisy aircraft would be banned from using the airport from 9 p.m. to 6 a.m. During the hours from 6 a.m. to 9 a.m. and from 6 p.m. to 9 p.m., each operator of a noisy aircraft (such as Surf Air, a charter company, a flight school or a private individual) would be allowed only one takeoff and one landing in each time period.
As written, the restrictions would eliminate 81 flights a week from Surf Air's current schedule.
Certain exceptions would apply, including for those working on certifications.
Ms. Ford said her group is "shocked by the proposed ordinance" and questions its legality. The airport association and others opposed to the curfew have pointed to a recent federal appeals court ruling against a curfew imposed at an airport in East Hampton, New York.
San Mateo County's proposal, however, seems to be designed to avoid the problems the East Hampton curfew has faced by exempting certain classes of aircraft, such as jets and helicopters, which are strictly regulated by federal law.
The ordinance exempts what are labeled "Stage 2, 3 and 4" aircraft. Federal regulations govern those classes of aircraft and prohibit more stringent local regulations.
Mike Callagy, San Mateo County's assistant county manager, said the proposed curfew "is much more narrowly tailored to aircraft causing disturbances" than the South Hampton regulations.
Ms. Ford said that many at the airport hope an alternative route Surf Air used during a six-month trial period will be approved for permanent use by the Federal Aviation Administration. The route sent Surf Air over the Bay instead of the Peninsula for more than 60 percent of its flights during the trial.
But county officials say it could take 18 months, or longer, for the FAA to decide about the route. The route had drawn complaints from residents of Sunnyvale who said it increased the number of planes flying over their homes, but San Mateo County officials say most of those complaints were from people who did not live under the new flight path.
The Bay route also did not address noise complaints from those who live under Surf Air's departure routes, including residents of San Carlos, Redwood Shores and North Fair Oaks.
The Bay route removed Surf Air's planes from flying over "the handful of residents who have been complaining" much of the time, Ms. Ford said.
"If the Supervisors really believe that this very substantial improvement (of the Bay route) is still not enough to satisfy the individuals who are driving this issue, then the supervisors should be drafting an ordinance that does what they already admit they intend to do: target Surf Air," she said in an email, acknowledging that such an ordinance would not be valid.
Ms. Ford said Surf Air is "the target of this ordinance" but the proposed regulations punish "airport users who have peacefully coexisted with the community for many years."
She also suggested that a prerequisite to any changes is the completion of a recently started county noise study.
"The San Carlos Airport Association has always strived to be a good neighbor to our friends in the surrounding communities," Ms. Ford said. "For almost 20 years we've peacefully coexisted, and as we heard at recent meetings of the Board of Supervisors, our neighbors have been friendly toward us."
Ms. Ford suggested that the supervisors devote their energy and taxpayer funds to "engage the flying community to work together for alternate solutions."
The county said the proposed ordinance and other possible ways to lessen noise complaints will probably be considered by the Board of Supervisors in July.
In the meantime, the county will meet with local residents and airport users as well as public officials from the affected communities to discuss the proposed curfew.