The Air Affair

Flying the San Francisco Bay Area

Introduction Airspace Weather Airports Attractions Sights Destinations

Airspace: ABC's of Negotiating the B, C, and Ds

The Bay Area airspace is dominated by the 10,000-ft tall SFO Class B. Nestled against the underside of the Class B are two Class C's for Oakland and San Jose, and Class D's for San Carlos, Hayward, Palo Alto, and Moffett. Reid-Hillview's Class D lies 1 mile outside the 30-mile SFO Class C veil. Adding to the complexity are the coastal and Diablo mountain ranges that enclose the central portion of the Bay Area in a narrow V shape.

Despite it's complexity, the Bay Area airspace is easily navigated if you learn the in's and out's. Controllers are generally friendly and accommodating, even to the little airplanes. But between traffic volumes, navigation, and radio work, pilot workload can be high. The combination of airspace and terrain also creates traffic choke points that require a high level of diligence. The figure below shows areas where airspace and terrain force traffic into low altitudes often in opposite directions of travel:

Golden Gate vicinity: this is prime sightseeing territory, including the Golden Gate Bridge, San Francisco waterfront, Alcatraz Island, Angel Island, and Sausalito. It is also outside the class B below 3,000 feet, so expect many sightseeing aircraft wandering unpredictably and not talking on the radio. Norcal may be able to provide traffic advisories based on their workload.

Pacific shoreline: where the SFO Class B bottoms out at 1500 feet AGL (or more accurately Above Water Level), traffic is heavy beneath this sector, with aircraft both north and southbound just off shore. Lack of radar coverage means traffic advisories are unavailable. Also watch for hang gliders along the cliffs near Lake Merced, a lake just inland from the beaches between Pacifica and Golden Gate Park.

Interstate 580: terrain and the OAK class C concentrate HWD arrivals and departures along the Interstate 580 corridor. Contact HWD or OAK tower at least 10 miles out for traffic advisories.

Sunol Pass: approximately midway between Livermore and San Jose airports, this pass is the prime westbound arrival and eastbound departure corridor for RHV, SJC, PAO, and SQL. Look sharp for opposite direction traffic, and stay below 3500 MSL, as this is also the arrival area for airliners and biz jets into OAK at 4000 and above. Power lines cross the 680 freeway just east of the summit. Radar coverage is also poor here.

Dumbarton Bridge: Palo Alto arrivals and depatures, and aircraft transitioning to and from the coast are concentrated here.

RHV to UTC: coastal hills to the east and SJC approaches and class C to the west squeeze RHV northbound arrivals and southbound departures into this narrow corridor. It is not unusual to find yourself in loose formation with other aircraft when arriving at the visual call-up point UTC, a group of industrial buildings about 1 mile east of Highway 101. Be alert for opposite direction traffic, and remain clear of the airliner approaches into SJC by staying on the northeast side of Highway 101.


The central core of the SFO class B and OAK class C are really the only no-fly zones in the Bay Area. North-south and east-west transitions are possible if these areas are avoided.

The westernmost north-south transition is directly along the Pacific coast. Aircraft need no clearance as long as they remain offshore. However, the transition must be made below 1500 feet MSL under the floor of segment I of the SFO class B.

Transitioning the class B over the San Franicsco penninsula is often referred to as the "Bay Tour". A common starting point from the south is at 3500 feet MSL over the Woodside VOR (OSI). The Bay Tour can also be requested from ground control when departing from either SJC or RHV. Once cleared by Norcal into the class B, an altitude of 3500 feet is typically assigned, with instructions to remain south and west of Highway 101 (also referred to as the Bayshore). Two major highways travel the penninsula: Highway 101 along the eastern side near the bay, and Interstate 280, through the hills just east of the ridgeline. Remaining between these two highways will keep you well clear of the SFO arrivals. The figure below shows a typical route:

For a northbound transition, once you pass north of SFO, Norcal will allow you to step down to 2500 or 2000 feet to cross over the western side of San Fransico and Golden Gate Park. Doing so will take you out of the class B airspace, so if workload is high, Norcal may terminate radar services. However, much of the time, traffic advisories will be available until well north of Angel Island. Norcal's airspace ends just north of Angel Island, so for continued flight following north, you will be handed off to Oakland Center.