A partial power outage at San Francisco International Airport caused brief confusion and inconvenience for travellers on Wednesday morning.

What Was Impacted?

The outage impacted SFO Terminals 1, 3, and the international terminal. It started around 5:30 am local time and only lasted until 7:30 am. However, the effects of the outage were felt for much longer.

SFO's Terminal 2 was spared from the outage.

Flight information displays and escalators were shut off. Other systems used in airport formalities like check-in and security check were also impacted, causing lines at check-in and TSA areas to grow longer than normal on a typical Wednesday morning.

Certain passengers reported unusual sights like certain airport doors being shut at times when they should be open. This caused some confusion at the time since no one was aware that parts of the airport were suffering an outage.

It should be noted that despite certain terminals and their systems temporarily losing power, the SFO Airport Control Tower never lost power.

While airport power outages are very rare instances, authorities and employees working on-site are always ready to respond in such cases.

Airport officials have not yet determined the cause or root of the outage as of now.

Delays

According to Flightradar24 data, various departing flights were delayed from 6:00 am and beyond. There was not a singular block of time in which departing flights were impacted as sporadic delays continued to last throughout the day.

Flights from various airlines were impacted. The bulk of the delays occurred in the morning between 6:00 am and 10:00 am, affecting major carriers like United Airlines and Alaska Airlines.

Delay statistics from FlightAware report that more than 150 flights were delayed before noon.

Most arriving flights landed in San Francisco without issue. However, internationally arriving passengers were temporarily disrupted after landing. 

Thanks to the outage affecting the international terminal, the U.S. Customs facility was briefly closed, causing passengers to wait onboard their planes until further notice. 

In one instance, the wait was about 90 minutes. Other flights that were due to arrive in San Francisco during the outage from nearby origins were delayed before even getting airborne.

Because the outage began at 5:30 am, flights inbound to SFO from places like Las Vegas, Santa Ana, Fresno, Jackson Hole, Phoenix, and others were delayed an hour minimum.

Ironically enough, the outage happened the same morning Alaska Airlines moved its operations from Terminal 2 to Terminal 1, also called the "Harvey Milk Terminal".

Despite some delays continuing to persist into the afternoon and evening, power has been fully restored at the terminals since morning, and operations are back to normal.

SFO's Harvey Milk Terminal (Terminal 1) is, despite the brief disruption, undergoing a massive expansion and renovation. Part of that renovation saw new carriers moving in, such as Alaska Airlines. Frontier, Hawaiian, and Sun Country are also slated to move to Terminal 1 soon.

San Francisco International Airport is the second-busiest airport in California and 14th-busiest in the United States by passenger count. It currently serves as the fifth-largest hub for United Airlines and the airline's main gateway to the Asia-Pacific region.

SFO served over 50 million passengers in 2023, an 18.7% increase from the year prior.