Community FAQs

Airports are categorized as national, regional, local, or basic by the Federal Aviation Administration (FAA). The FAA then further labels airports as commercial service, primary, cargo service, reliever, or general aviation.

The SQL and HAF airports are both classified by the FAA as local reliever airports, meaning they help relieve congestion at commercial service airports and provide improved general aviation access. Reliever airports serve general aviation flights and can accommodate air taxi/charter flights with less than 10 passengers. They are not considered commercial airports.

We are happy to answer questions and discuss your concerns about aircraft noise, provide maps of flight paths, or any other data to help you make an informed decision. Please call our office at 650-573-3700 to speak with Davi Howard, our Airport Communications Specialist.

The FAA uses the number of airport operations to define airport activity levels. An operation is an aircraft takeoff or a landing. For example, a “touch and go” conducted by a training aircraft includes both a takeoff and a landing, and counts as two operations.

San Carlos Airport – In 2017, San Carlos Airport had a total of 114,618 aircraft operations. That is on average, 13 operations per hour, 24 hours a day. However, since most of the traffic is concentrated in the daytime hours, there are approximately 22 operations per hour. 

Like our roads and highways, the airport has peak commute and travel hours and days.  In 2017, the busiest day and times were Saturdays from 12:00 pm to 4:00 pm and Sundays from 11:00 am to 5:00 pm.

In the last 20 years, the highest number of operations at the San Carlos Airport took place in the year 2003 with over 171,105 aircraft operations. General aviation operations at airports nationwide, including San Carlos and Half Moon Bay airports have declined approximately 40 percent since 2000.

Half Moon Bay Airport – Since the Half Moon Bay Airport does not have an air traffic control tower to track airport operations, the County of San Mateo estimates the annual number using an FAA-approved methodology. The annual number of operations at the Half Moon Bay Airport is estimated at 50,000. While that’s an average of 137 aircraft operations per day, the weather on the coast (overcast approximately 40% of the year) creates clusters of airport operations resulting in busy days when the weather is clear, and days, or sometimes weeks, of little activity when the weather is overcast.

The San Carlos Airport and Half Moon Bay Airport are surrounded by noise sensitive neighborhoods. The County of San Mateo, pilots associations, airport staff, community groups, and the FAA developed a robust voluntary noise abatement program (VNAPs) as a “fly friendly” policy to reduce overflight disturbances for our neighbors. Please read the VNAPs for each airport on our Preferred Flight Procedures page.

Half Moon Bay Preferred Flight Procedures page

San Carlos Preferred Flight Procedures page

While the SQL and HAF airports work collaboratively with our local Air Traffic Control tower and various FAA offices to reduce noise for the community when possible, we do not have control over how and where aircraft fly. As soon as an aircraft is airborne, it is under the jurisdiction of the FAA.

Both the SQL and HAF airports are designated as public use airports by the FAA, meaning they are open and usable 24 hours per day, seven days per week, in most weather conditions. However, most aircraft traffic occurs during the daytime.

Air Traffic Control Tower Hours – The Air Traffic Control Tower at San Carlos Airport is open from 7:00 a.m. – 9:00 p.m. every day. There is no tower at Half Moon Bay Airport.

Airport Personnel/Office Hours – The Airport Office at San Carlos Airport is open from 8:00 a.m. – 5:00 p.m. Monday through Friday, excluding holidays. At San Carlos, operations staff are on-duty from 7:00 a.m. – 9:00 p.m. every day. At Half Moon Bay, operations staff are on-duty from 8:30 a.m. – 4:30 p.m. every day.

Aircraft must arrive and depart into the wind. The runways at SQL and HAF are aligned with the predominate wind directions.

In the Bay Area, the wind direction is primarily from the northwest. This results in aircraft arriving and departing to cardinal northwest. During inclement weather days (low clouds, etc.), the wind direction is primarily from the southeast and aircraft will arrive and depart to cardinal southeast.

Approximately 85 percent of the traffic at the San Carlos Airport and Half Moon Bay Airport arrive and depart to the northwest. For noise abatement, both airports use southeasterly departures when the wind is less than 5 knots (the “calm wind” departures). This voluntary noise abatement procedure is typically used in the mornings.

The areas immediately surrounding the airports, below the traffic patterns, and below the arrival and departure flight paths will experience aircraft overflights. The County, its pilots associations, community groups, and the FAA worked together to develop a robust Voluntary Noise Abatement Program (VNAP) for the San Carlos Airport and Half Moon Bay Airport to minimize noise impacts to surrounding communities whenever possible.

Most pilots voluntarily follow the VNAP, which reduces a great deal of overflight noise for our neighbors. However, it is impossible to completely eliminate overflight disturbance for residents living near a flight path. 

No. Due to the volume of air traffic in the Bay Area arriving and departing the San Francisco International Airport (SFO), Oakland International Airport (OAK), Norman Y. Mineta San Jose International Airport (SJC), and reliever airports—and with both the SQL and HAF airports being located below SFO’s highly restricted Class Bravo airspace—it is not possible to move flight paths without impacting the entire system of airports. 

There are two ways to file an aircraft noise complaint for the SQL or HAF airports. Please provide as much information as possible to help airport staff review and process your complaint.

1. Complete and submit our noise comment form.
2. Leave a message on our noise comment hotline at 844-266-6266.

The FAA requires the airports’ noise abatement program to be voluntary. County of San Mateo Airports does not refer comments to the FAA. Neighbors can report aircraft they believe violate Federal Aviation Regulations (FARs) directly to the FAA’s hotline reporting form.

Federal regulations require a minimum altitude of 1,000 feet over congested areas and 500 feet over non-congested areas. The exceptions to this rule are helicopters and aircraft that are in the process of taking off or landing (including the traffic pattern area and performing touch and goes). The FAA explains that helicopters “have unique operating characteristics, the most important of which is their ability to execute pinpoint emergency landings during power-out emergencies. Furthermore, the helicopter’s increased use by law enforcement and emergency medical service agencies requires added flexibility (www.faa.gov/aircraft/safety/).”