By Andrew Mills, Elena Rodriguez and David Shepardson

EDINBURGH/MADRID/BALTIMORE (Reuters) – Air passengers around the world faced delays, cancellations and problems checking tickets as airports and airlines were caught in a massive IT outage that also affected industries from banks to media companies.

Some airlines and airports said they were back online, with the US government hoping to have the transport system back to normal by Saturday.

Of the 110,000 scheduled commercial flights on Friday, 2,691 have been canceled worldwide so far and more are expected, according to data from global aviation analytics firm Cirium.

In Edinburgh, a Reuters witness said boarding pass scanners brought up a “server offline message”, with the airport saying passengers should not travel to the airport without first checking their flight status online.

Elsewhere, airports and airlines advised customers to arrive earlier than normal for flights. Analysts said the outage was likely linked to a bug in Microsoft (NASDAQ: ) software used worldwide.

The aviation sector is particularly hard hit because of its sensitivity to timing. Airlines rely on a tightly coordinated schedule that is often directed by air traffic control. A delay of just a few minutes can throw off the flight schedule for takeoffs and landings for an airport and an airline for the rest of the day.

Microsoft said users may not be able to access various Office 365 apps and services due to a “configuration change in a subset of workloads supported by Azure.”

Hong Kong International Airport said a Microsoft outage was affecting many airlines and had switched to manual check-in, but flight operations were not affected. Singapore’s Changi Airport also said check-ins were handled manually.

Cybersecurity firm Crowdstrike said it is working with customers affected by a flaw found in a content update for Microsoft Windows hosts.

CHAOS

Airlines in the United States, Asia and Europe, including major carriers such as Ryanair, Delta Air Lines (NYSE: ) and Air India, said they either experienced delays or disruptions.

Even airlines not directly affected said they would face delays due to the global nature of the outage.

The outage caused chaos for passengers on one of Europe’s busiest travel days of the year as schools broke up for holidays.

At Madrid-Barajas airport, passengers complained of queues and a lack of information.

“No one was around to tell us where we could check in when we arrived… so different groups were queuing in different places and finally someone, after there was a line of people, told us to come here,” said Ana Rodriguez. said a tourist from Mexico.

In India, airlines at New Delhi Airport’s Terminal 3 were handing out handwritten boarding passes to fliers, while airport staff were using whiteboards to display gate information for flights, according to an airport official.

At the Baltimore airport, Rose Geffrard, 37, a nurse traveling with her six-year-old son and four-year-old daughter to a cousin’s wedding in Boston, said she spent nearly two hours waiting in a long line to get paper tickets. Spirit Airlines (NYSE:) staff searched for their names on a paper manifest.

Airline staff had to page through the paper passenger manifest before issuing paper tickets and then consult a paper seat chart to make sure they weren’t assigning duplicate seats. The long process led to long waits.

Several US carriers, including American Airlines (NASDAQ: ), United Airlines and Delta, issued ground stops for all their flights early Friday due to communication problems, according to the US Federal Aviation Administration (FAA).

SLOW SOLUTION

American Airlines later announced that it had resumed operations. Delta said it has resumed some flight departures, but warned of additional delays and cancellations. FAA data showed that Delta’s operations in Atlanta, Detroit, Minneapolis and Salt Lake City were still affected.

There are more than 27,000 flights scheduled Friday from the US, carrying up to 3.7 million passengers, according to Cirium data.

The transportation system issues appeared to be resolved and we hope to return to normal operations by Saturday, US Transportation Secretary Pete Buttigieg said, adding that the FAA does not appear to be affected.

In Europe, Spanish carrier Iberia said it had managed to avoid flight cancellations.

However, Amsterdam Schiphol Airport, Berlin Airport, London Gatwick, Edinburgh Airport and others said they were affected by the disruption, with flight tracking service FlightRadar24 citing Schiphol as the airport with the worst disruption worldwide.

A Schiphol spokesman said flights to and from the airport were affected, adding that it was not yet clear how many and that travelers were advised to contact their airline.

INDEMNIFICATION QUESTIONS

In Europe, airlines are required to compensate passengers for delays of more than three hours, but it was unclear to what extent they would be held legally responsible for the disruption.

“The airlines will have to prove that this was in fact an exceptional circumstance,” said a spokesman for the European consumer organization BEUC.

“If this is the case, passengers will not receive compensation, according to EU law.”

Major US airlines in 2022 pledged to provide meals to customers with a three-hour delay and hotel rooms for stranded passengers if caused by issues within the airlines’ control.

Unlike in Europe, there is no legal requirement for airlines in the United States to compensate passengers for long delays. It is also unclear whether the IT issue will be considered the airline’s cause of the delay or not.