By Andrew Mills, Elena Rodriguez and David Shepardson

EDINBURGH/MADRID/BALTIMORE (Reuters) -Air passengers worldwide faced delays, flight cancellations and headaches checking in as airports and airlines were caught up in a massive IT outage that has affected numerous industries ranging from banks to media companies.

A software update by global cybersecurity firm CrowdStrike triggered systems problems for Microsoft customers that turned into hours of delays for airlines using their software. Some travelers were issued handwritten boarding passes with software inoperative.

All told, out of more than 110,000 scheduled commercial flights on Friday, 5,000 have been cancelled globally with more expected, according to global aviation analytics firm Cirium. By comparison, 2,000 flights were cancelled on Thursday, before the software issues.

The aviation sector is particularly sensitive to interruptions due to its reliance on closely coordinated schedules run by air-traffic control. Delays can throw off schedules for airports and airlines for the rest of the day.

U.S. carrier Delta Air Lines was one of the hardest- hit, with 20% of its flights cancelled, according to flight tracking service FlightAware.

Across the United States, Asia and Europe, carriers such as Ryanair, United and Air India said they had faced delays or disruption.

“Nobody was around to tell us where we could check in when we arrived … so different groups queued in different places and then in the end someone, after a bottleneck of people was formed, told us to come here,” said Ana Rodriguez, a tourist from Mexico, while waiting for a flight in Madrid’s Barajas Airport.

Even airlines that were not directly affected said they would have to grapple with delays due to the global nature of the disruption.

Transportation system issues appeared to be resolving and would be hopefully be back to normal by Saturday, said U.S. Transportation Secretary Pete Buttigieg, adding that the U.S. Federal Aviation Administration did not appear affected.

FLIGHT DISRUPTIONS

Atlanta’s Hartsfield-Jackson airport, one of the world’s busiest and a hub for Delta Air, had the worst disruptions globally, according to FlightRadar24, with 36% of scheduled departures cancelled.

Delta resumed some flight departures but warned of additional delays and cancellations. FAA data showed Delta’s operations in Atlanta, Minneapolis and New York were still affected. Customers who had flights cancelled were issued travel waivers, the airline said.

United said the disruption affected systems used for calculating aircraft weight, check-ins, and its call centers.

In Europe, Spanish carrier Iberia said it had managed to avoid flight cancellations. Ryanair had cancelled 2% of its flights, while 38% of its scheduled flights were delayed.

HANDWRITTEN BOARDING PASSES

The outage sparked chaos for European passengers on what was one of the busiest travel days of the year as schools broke up for holiday.

In Edinburgh, a Reuters witness said boarding-pass scanners carried a “server offline message,” with the airport saying passengers should not travel to the airport without checking their flight status first. Amsterdam’s Schiphol airport, Berlin airport and London Gatwick were also affected.

In India, airlines at New Delhi’s Terminal 3 were giving handwritten boarding passes to flyers, while airport staff were using whiteboards to display gate information, according to an official for the airport. Airports in Hong Kong and Singapore also switched to manual check-in.

At Baltimore/Washington International Thurgood Marshall Airport in Baltimore, Maryland, Rose Geffrard, 37, a nurse travelling with her two children to a cousin’s wedding in Boston, said she spent nearly two hours waiting in a long line to get paper tickets.

Spirit Airlines personnel had to page through printed passenger manifests before issuing paper tickets and then consulted a printed seating chart to make sure they were not double assigning seats.

COMPENSATION 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 outage. Airlines would have to prove the outage was an extraordinary circumstance to not compensate passengers, a spokesperson for European consumer organization BEUC said.

Major U.S. airlines in 2022 committed to providing meals for customers delayed by three hours and hotel rooms for stranded passengers if prompted by issues under the airlines’ control.

Unlike in Europe, there is no legal requirement that airlines in the United States compensate passengers for lengthy delays. It is also not clear if the IT issue will be deemed an airline-caused delay or not.

(Reporting by Reuters bureaux, James Pearson in London, David Shepardson in Washington, Alexander Cornwell in Dubai, Lisa Barrington in Seoul; Writing by Joanna Plucinska and Rajesh Kumar SinghEditing by Mark Potter, David Evans and Matthew Lewis)

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