SFO parallel runway restrictions imposed by the US Federal Aviation Administration (FAA) are set to cut arrival capacity at San Francisco International Airport by roughly half, compounding the impact of a separate runway repaving project that began on 30 March 2026.
The FAA announced the new safety measures on 31 March, one day after construction work on Runway 1 got under way. That repaving project, which is expected to run until 2 October 2026, had already required operators to redirect traffic to Runways 28L and 28R. Under the original plan, SFO projected that fewer than 15% of flights would be delayed, with average hold times of under 30 minutes.
The FAA’s intervention has overturned those projections entirely.
Why the FAA Moved to End SFO Parallel Runway Operations
An internal FAA review concluded that Runways 28L and 28R, which are separated by just 750 feet, do not meet the agency’s aircraft separation policy. That policy requires a minimum of 4,300 feet between runways for side-by-side approaches, more than five times the current spacing at SFO. The airport had long relied on visual separation rules to permit simultaneous parallel approaches on those east-west runways, a procedure the FAA’s review has now found to be non-compliant.
The FAA has cited the crash of American Airlines Flight 5342 as context for the new mandate. That aircraft collided with a Black Hawk helicopter over the Potomac River, with all 67 people on both aircraft killed. In that incident, visual separation between aircraft was a factor in the collision.
‘San Francisco International Airport will experience some flight delays due to a runway repaving project and an FAA safety measure. It requires staggered approaches, with one aircraft offset from the aircraft on the parallel runway,’ the FAA told the SF Chronicle.
The staggered approach pattern introduces a typical hold of around 30 minutes per aircraft. The practical effect is a reduction in SFO’s arrival rate from 60 flights per hour on fair-weather days to approximately 30 flights per hour.
SFO Capacity Outlook Under the New SFO Parallel Runway Restrictions
According to San Francisco International Airport, as many as a quarter of all flights may now be delayed, with wait times increasing by 30 minutes or more. Half of that capacity reduction is attributable to the runway repaving project; the other half to the newly mandated flight patterns.
Critically, the FAA has confirmed that parallel landings will be prohibited even after the repaving work finishes. That means the capacity constraints are not a temporary by-product of the construction schedule: the arrival rate reduction will remain in place once Runway 1 reopens in October.
That permanence is worth placing in context. As the Infinite Flight Community notes, the parallel approaches at SFO were never conducted in poor weather or when instrument landing system (ILS) approaches were in use, and no crash has ever been linked to the procedure. The FAA’s decision to ban them outright in all conditions therefore goes beyond the direct lessons of previous incidents and reflects a broader re-evaluation of separation standards at closely spaced runways.
For airline operations teams and ground handlers at SFO, the implications are considerable. Load factor management, minimum connect times and slot planning at one of the busiest hubs on the US West Coast will all need to account for a structurally lower throughput rate for the foreseeable future. United Airlines, which operates a major hub at the airport, has advised travellers to monitor flight updates closely given the ongoing disruption.
With the repaving project not due for completion until 2 October 2026 and the parallel approach ban permanent beyond that date, operators serving SFO face an extended period of schedule pressure well into the second half of the year.
