Thousands of flights affected after global IT outage — what we know

Editor note: This article has been updated with the latest information.

Flight cancellations and delays continue to mount hours after a tech glitch first caused disruptions across a wide range of industries worldwide. And airlines warn some travel problems may continue into the weekend.

The massive IT outage led some airlines to temporarily ground planes Friday, on what was expected to be one of the year's busiest travel days. The problems have shown up well beyond airports, too, stretching from rail travel to hotels and theme parks.

That's on top of outages affecting plenty of other critical systems like banks and medical facilities.

As of 4:30 p.m. EDT, airlines had canceled more than 2,600 flights in the U.S., according to data from flight-tracking site FlightAware. More than 8,800 flights had been delayed in the U.S.

However, the disruptions extend worldwide, with more than 5,100 flights canceled globally, according to aviation analytics firm Cirium. This amounts to 4.6% of all scheduled flights.

"Many flights are impacted as systems recover," Transportation Secretary Pete Buttigieg wrote on social media Friday morning. "We're continuing to address effects on transportation systems from today's widespread tech outage."

The disruptions came a day after the Transportation Security Agency reported its agents screened more than 2.9 million passengers on Thursday — its third busiest day of all time.

Here's a breakdown of what happened, the cause of the issue, who's affected and what you should do if your travel plans are affected.

Daily Newsletter

Reward your inbox with the TPG Daily newsletter

Join over 700,000 readers for breaking news, in-depth guides and exclusive deals from TPG’s experts

Email address

Sign up

By signing up, you will receive newsletters and promotional content and agree to our Terms of Use and acknowledge the data practices in our Privacy Policy. You may unsubscribe at any time.

What has happened?

In an unexpected turn of events, a tech glitch at a major cybersecurity firm has wreaked havoc on IT infrastructure worldwide.

In the travel sector, the outage has triggered widespread disruptions, including significant effects on air travel, due to disruptions at third-party vendors used by many carriers.

The problems affected technical operations at numerous airlines and forced carriers to ground flights at various points Friday morning.

Residual cancellations and delays continue to mount even as systems have come back online.

What is the cause of the IT outage?

The outage was caused during a software update at CrowdStrike, an Austin-based cybersecurity firm.

The cybersecurity company confirmed that the tech issues were not a result of a security incident or cyberattack, adding that its team was "fully mobilized to ensure the security and stability of CrowdStrike customers."

The update released by CrowdStrike reportedly left Windows PCs showing the infamous "blue screen of death," rendering many computer systems unusable.

Air travel disruptions in US

The outage has affected numerous major companies and services globally — with disruption reports ranging from major banks to airlines, hotels and rail operators.

The problems have been particularly widespread at U.S. airlines.

Each of the three largest carriers — American Airlines, Delta Air Lines and United Airlines — employed ground stops at various points Friday morning.

Delta has led the way among U.S. carriers with more than 1,200 cancellations between its mainline and regional flights. Though the Atlanta-based carrier resumed flying around 8:00 a.m. EDT Friday after pausing its global operation, the disruptions cascaded over the course of the day.

Delta expects some disruptions will continue into the weekend. And, as a result of the outages, unaccompanied minors (under the age of 18) will not be able to fly solo on Delta until Sunday, July 21. The airline also noted it's providing meal vouchers and accommodations for customers stranded overnight.

Delta is far from the only airline affected, though.

Though American Airlines and United Airlines also began to resume some flights after pausing operations early Friday, the two carriers have collectively canceled more than 700 flights, FlightAware data shows.

"We are resuming some flights but expect schedule disruptions to continue throughout Friday," a United spokesperson told TPG in a statement. The spokesperson noted that the problems early Friday affected key operations like calculating aircraft weight, check-in and phone systems.

Spirit Airlines has likewise reported disruptions to its reservations system and flight operations. Though systems were coming back online late Friday afternoon, the budget carrier warned some problems could persist into the weekend.

TSA, FAA not affected

Despite the challenges airlines faced Friday, the outages do not appear to be affecting major operations at the TSA or Federal Aviation Administration.

At the FAA, that means control towers and other critical air traffic systems should be functioning normally.

The FAA has, however, advised: "Ground stops and delays will be intermittent at various airports as the airlines work through residual technology issues."

TSA checkpoints should be operating normally.

"TSA is monitoring the IT system issues throughout the transportation system in partnership with stakeholders and other agencies. There has not been any impact to TSA operations," a TSA spokesperson told TPG in a statement.

That's good news, considering the 10 busiest days ever have each come since Memorial Day weekend — with many of the busiest days this summer falling on Fridays.

Travel advisories in place

Most major U.S. airlines have put travel advisories in place. This allows travelers to have extra flexibility in changing tickets, even when booked on a more restrictive fare that doesn't typically allow itinerary changes. If your trip is affected — or you think an upcoming flight might be — check your airline's website or app to see if the carrier is offering you options to switch your travel plans.

DOT: Passengers eligible for meals, hotels, ground transit compensation

The DOT is treating Friday's cancellations and delays as "controllable" on the part of airlines, a spokesperson for the agency told TPG Friday.

That means the agency expects airlines to compensate stranded passengers for meals, hotel night(s) and ground transportation as specified on the agency's Airline Customer Service Dashboard. The page, found at FlightRights.gov, lays out accommodations airlines have promised to make in the event of flight cancellations or major delays.

Is Global Entry working?

Travelers arriving home in the U.S. after an international flight can expect a longer-than-normal wait, U.S. Customs and Border Protection told TPG. It cited ongoing processing delays amid the IT problems.

However, all of the agency's apps, including the Global Entry mobile app, are operational, a spokesperson said.

European air travel affected

The IT outage has come during the busiest day of the year so far for U.K. airports. Cirium data shows more than 3,214 U.K. flight departures were expected July 19 — the highest number since October 2019. More than 9,000 flights are currently scheduled to depart from U.K. airports alone over the weekend.

Scores of flights were canceled across London's airports — and elsewhere in Europe Friday.

At British Airways, the outage "caused issues across our operational systems," a spokesperson for the carrier said.

Other carriers from Air France and KLM to Vueling and Ryanair noted problems over the course of the day Friday.

At U.K. airports, travelers reported widespread disruptions throughout the terminals at London Gatwick Airport (LGW), from faulty check-in systems to e-gate malfunctions.

A spokesperson for Heathrow Airport (LHR) told TPG the airport was "implementing contingency plans to minimize any impact on journeys," and advised passengers to check with their airline.

Disruptions stretch beyond air travel

Beyond airports and airlines, the outage is also affecting operations on train services, hotels and theme parks.

TPG director of content Summer Hull reported that, at one point, the Park Hyatt Paris-Vendome was resorting to pen and paper for bills and receipts due to its computer systems going down. Meanwhile, Disneyland Paris was also using paper printouts to display ride wait times.

Menu screens displaying the dreaded "blue screen of death" were also spotted at restaurants within Disneyland Paris.

Elsewhere, TPG senior editor Becky Blaine was unable to check into Hotel NH in Essen, Germany. A staff member with a master key had to individually let hotel guests into their rooms after the keycard machine suffered issues due to the outage.

Govia Thameslink Railway — the U.K.'s busiest train operator — reported widespread IT problems Friday, leading to potential train cancellations and disruptions in real-time information. Sky News was also forced to temporarily go offline in the U.K. this morning, displaying an error message to viewers.

Eurostar has confirmed to TPG that its services have not been affected by the IT outage; while some of its partners may see disruptions later in the day, they "haven't seen this yet."

What should I do if I'm affected?

You should be both proactive and realistic if your flight is delayed or canceled.

Download your airline's app

Start by regularly monitoring your flight status on the airline's website or app. If you haven't downloaded your airline's app, now is a good time to do it. The app often has more up-to-date flight departure information than what's on the departure and arrival boards at the airport.

Oftentimes, you can make itinerary changes right on your phone.

Sign up for notifications — whether app notifications, text messages or email — so that you can be alerted as quickly as possible about any changes to your travel plans. Here are details on that process with American Airlines and United Airlines.

Monitor your flight ahead of time

We also recommend monitoring where your plane is coming from. This may help you understand the likelihood of your flight departing — and when that might be. Your airline's app may show this.

If not, use Flightradar24, to see the location of every aircraft in the world at the present moment. By searching for your flight number on Flightradar24, you can find the exact aircraft that will operate it (by following the aircraft's serial number/registration). Maybe your flight is scheduled to board soon, but the plane operating your flight will operate another sector before yours and it has not yet left that airport. In that case, your flight will likely be delayed because the inbound aircraft will be late.

Expect to be put on hold

Calling the operating airline is not advisable as you can expect long wait times and overwhelmed agents who may be unable to provide any additional information beyond what you already know. This is an ongoing situation that is affecting pretty much all travelers right now.

Stay calm and know your rights

If your flight is canceled, you should be automatically rebooked on another service by your airline. Depending on the severity of this outage for your airline, that new flight may be many hours, if not days, after your original departure time.

You can proactively look for other flight options if you haven't been booked onto a new service or your new flight is unsuitable. This can usually be rebooked through the airline's app. It's best to do this as quickly as possible, as other affected passengers scramble to book these alternate services.

Under DOT policy in the U.S., you are entitled to a refund for the unused portion of your ticket if you ultimately choose not to fly.

If you are flying to or from Europe, delays and cancellations would not be eligible for EU261 compensation, as this issue is beyond the airlines' control.

Related: Here are the airline passenger rights to know during a travel meltdown

Arrive at the airport on time and be understanding

If your flight is still listed as "on time" when you check the app, leave for the airport according to the original schedule. If possible, allow some extra time for check-in and security, just in case. So if you normally arrive at the airport two hours before departure, try arriving three hours before departure today.

Finally, be realistic about the situation and be kind to frontline airline and airport staff. Even if this outage is fixed quickly, the flow-on effect could last days during such a busy travel period. Thousands of other passengers are caught up in this situation beyond the airline's control, and many people will have their travel delayed or canceled.

The airline staff will face many unhappy passengers through the weekend. Please be patient with them so you can get on your way as quickly as possible.

Related reading:

• Key travel tips you need to know — whether you're a beginner or expert traveler
• The best travel credit cards
• Where to go in 2024: The 16 best places to travel
• 6 real-life strategies you can use when your flight is canceled or delayed
• 8 of the best credit cards for general travel purchases
• 13 must-have items the TPG team can't travel without