San Francisco International Airport is warning travelers to expect delays after the Federal Aviation Administration increased the separation between arriving aircraft, a change that is reducing arrival capacity at the airport during an already disruptive period of runway construction. SFO says the impact is expected to cause delays of at least 30 minutes on about 30% of arriving flights.
The timing matters because SFO is already operating with a reduced runway setup. The airport announced that Runway 1R closed on March 30 for a six-month repaving project and adjacent taxiway improvements, with reopening expected on October 2. During that period, all arrivals are being handled on the airport’s two westside runways and all departures on the two bayside runways.
The FAA has tied the latest delays to both the construction project and a safety measure affecting how aircraft can land at SFO. In a March 31 statement, the agency said the airport would experience delays because of the runway repaving project and an FAA safety measure. SFO’s current travel alert says the FAA recently increased the separation between aircraft landing at the airport, adding to the disruption already caused by the runway closure.
The airport’s physical layout helps explain why the slowdown is especially significant in San Francisco. SFO says that on fair-weather days it can handle about 60 arrivals per hour, but during periods of low visibility, federal safety rules require aircraft to arrive single-file because the airport’s parallel runways are only 750 feet apart. That cuts arrival capacity to about 30 per hour and forces the FAA to use a Ground Delay Program to meter incoming flights.
The new FAA separation requirement is now layering onto that existing constraint. SFO has not described the change as a full landing ban, but the airport is telling passengers to prepare for slower operations and to check directly with their airline for flight-specific information.
For travelers, the practical effect is straightforward. Flights arriving in San Francisco are more likely to face delays, especially while the runway project remains active through early October. The airport’s advisory focuses on inbound traffic rather than a systemwide shutdown, and the official guidance remains to monitor airline updates before heading to the airport.
The situation also shows how sensitive SFO can be to operational changes during construction. Even under normal conditions, the airport’s runway geometry makes it more vulnerable than some other major hubs when visibility drops or arrival spacing increases. With one major runway closed and the FAA now requiring greater separation between arrivals, that margin has narrowed further.
For now, the disruption is expected to last well beyond a single day. SFO’s travel advisory says the runway is expected to reopen in early October 2026, meaning the combination of construction limits and reduced arrival rates could continue to affect flights throughout the summer and into the fall.
