SFO was planning to put two parallel runways into use for simultaneous landings of planes over the next six months, as it repaves one of its runways, but the FAA has stepped in to say 'No, you won't.'

Airport officials were trying to put a positive spin Monday on the first day of the closure of one of the airports north/south runways for a repaving project, suggesting that only about 10% of flights should expect to see delays during the next six months of the project.

But as Reuters reported Tuesday morning, the FAA has put a restriction on SFO in its plan to land pairs of planes simultaneously on its two east/west runways, saying that it will need to conduct staggered landings instead, which will lead to more delays. The FAA says the restriction will stay in place until the repaving and restriping project is complete, reducing the arrival capacity at SFO from 54 flights per hour to 36.

SFO typically is allowed to conduct simultaneous landings on the parallel 28L and 28R runways in clear weather, and staggered landings are only required during inclement weather. During this closure, these same two runways will be in use for all takeoffs as well.

In issuing the restriction, the FAA cited recent collisions and near-miss incidents at other airports, including a February 27 incident involving an American Airlines plane and a police helicopter in San Antonio. A United Airlines jet that had flown out of SFO also had a near-miss with a military helicopter at John Wayne Airport in Santa Ana last week.

Doug Yakel, the SFO spokesperson, who definitely was saying "less than 10%" of flights would be impacted back in December, now says they were anticipating 15% of flights to be impacted, and the FAA restriction raises that to 25%.

"The FAA has made us aware of this reduced arrival rate," Yakel said, speaking to the Chronicle. "While we were forecasting about 15% of flights being delayed by our runway project, we expect this change will increase the delay potential to approximately 25% of arriving flights experiencing a delay of at least 30 minutes. We are working with the FAA on ways to improve the arrival rate at SFO."

The repaving and restriping project will close both of the airport's north/south runways, 1L and 1R — the latter is being repaved, and the former will be used as an extra taxiway to reduce congestion. These two runways are typically used for 95% of all takeoffs.

United Airlines, which accounts for about half of all air traffic into and out of SFO, is likely to see the greatest impacts with flight delays.

As we noted yesterday, the current closure of Runway 1R follows recent, similar closures for repaving projects, including the closure of one of the major landing runways, 28L, in the first half of 2024. That closure also caused delays at the airport, but the closure ended in late June just as the busy summer travel season was picking up.

This closure is expected to last until October 1.

Previously: Six-Month Runway Closure at SFO May Cause Some Delays

Photo by David Syphers