**Update: 21/05/21 @ 14:20 UTC – Additional statement provided by Sabre.**

American Airlines was among a number of carriers experiencing IT issues today, resulting in flight delays and frustrated travelers. Photos and video posted to Twitter show crowded airport check-in halls as would-be travelers suffered through the outage. The source of the outage had to do with one of the carrier's systems provider, Sabre, which provides IT solutions for a large number of commercial airlines.

Reservation, check-in, and boarding issues across the country

Some airport check-in halls were crowded with travelers as a number of airlines experienced issues with their IT systems. Local North Carolina media outlet WRAL reports that crowds started to form as early as 05:00 local time, with additional reports that reservations could not be made on American's website.

In a statement to Simple Flying, American Airlines offered the following statement:

"Earlier today, Sabre had a technical issue that impacted multiple carriers, including American. This technical issue has been resolved. We apologize to our customers for the inconvenience."

The issue also affected Alaska Airlines. The airline's Twitter post demonstrated the extent of the system issues- reporting that planes were unable to board and were thus blocking gates.

Sabre told Simple Flying that several carriers were impacted but that the issue has since been fully resolved.

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Affecting flights down under

While the outage might have only lasted several hours, its impact was truly global. Indeed, Virgin Australia, another Sabre client, reported issues. One traveler at Melbourne airport told the Cairns Post that crowds formed after boarding gates were shut down across the country.

At Brisbane airport, all flights departing the airport from 16:50 local time onwards were delayed. A 20:15 flight to Adelaide was canceled. In total, 17 flights arriving and 17 flights departing saw delays. One arrival and departure was canceled.

A Virgin Australia spokesperson told The Cairns Post that airport staff had moved to manual check-in processes but that delays persisted.

Powering a large portion of the airline industry

The issue had to do with IT solutions provider Sabre. The firm's systems power everything on the passenger side, from bookings and seat reservations right through to booking management and check-in.

Sabre also offers airlines operational solutions for inventory management, boarding control, and flight crew scheduling, among many other services. According to ch-aviation, some 45 airlines are listed as being customers of Sabre. Notable carriers in addition to those mentioned above include:

• Aeroflot
• Ethiopian
• Etihad
• jetBlue
• Vietnam Airlines
• WestJet

UPDATE: After the publication of this article, Sabre provided us with the following statement,

“Dell/EMC has confirmed it experienced a hardware redundancy failure that impacted Sabre’s system, including PSS and check-in. The issue has been resolved. Dell/EMC is working to understand why the failure occurred.”

The risks of interconnectedness and reliance on IT systems

Considering the fact that airlines on all six inhabited continents are customers of the same IT solutions provider, today's incident involving Sabre demonstrates how much activity can be disrupted if that single service provider experiences issues. Interestingly, Amadeus IT Group has an even larger list of airline customers, numbering 136 for its Altea product and 63 for its NewSkies offering.

Indeed, it should be a wake-up call for enhanced security and redundancy within the industry. This is especially true due to the fact that almost all aspects of air travel are now electronic. Gone are the days of paper tickets for customers and paper lists for airlines- even boarding passes have become increasingly smartphone-based.

In an age where many aspects of our economy and daily life are at risk of hacks and cyberattacks, it's certainly something to be aware of.

Were you affected by Sabre's IT outage today? Please share your experience with us by leaving a comment.