Details have emerged as to the reason for a technical failure at Amadeus two weeks ago which affected the systems behind dozens of airlines.
Amadeus has declined to reveal how many of its airline customers were hit by the outage on Monday 30 January ("commercially confidential"), but says the incident was due to a "number of contributing network factors".
The outage lasted for up to three hours and hit the ALTEA system which is used to host over 100 airlines around the world including a number of high profile airlines such as British Airways, Qantas, Iberia and Cathay Pacific.
During this period, passengers were unable to self check-in online and reservation systems, agency bookings as well as airport counter systems were also affected.
As a result of ALTEA being hit, other GDSs such as Travelport and Sabre were also unable to make fare queries or bookings on airlines hosted by Amadeus.
The incident, Amadeus now says, occurred from a "network change to a module within our data centre enterprise network", located in in Erding, Germany.
The change was part of an "ongoing project to upgrade one of our main distribution switch pairs and the associated network access switches" - in other words: something went wrong during maintenance work in Erding, although whether it was human or mechanical error is unclear.
Amadeus is not shedding any further light on the incident - a failure which has surprised a number of figures in the tech community given that most of the systems used by GDSs are usually run in parallel, allowing a backup to kick in when a failure is reported.
Nevertheless, Amadeus says it is learning from the incident after making headlines around the world in both the tech and mainstream press.
An official says:
"As a result of this complex sequence of events, we are looking at a number of specifically targeted follow-up and improvement activities."