A computer crash has disrupted the travel plans of thousands of airline passengers including customers of Cathay Pacific, British Airways, Qantas and Iberia. The glitch in the Amadeus system meant that staff at airport check-in desks were forced to manually input passengers’ data rather than just scan their passports.

An industry source said that the meltdown had caused hours of irritation for passengers as they waited for the Amadeus system to be restored. The airlines affected by the disruption are all members of the oneworld alliance.

However, industry experts said that the problem had occurred at a time when airlines are not as busy as they are during peak holidays.

There are four main distribution systems used by the industry, but other booking programs run by Worldspan and Galileo were unaffected. Amadeus is yet to announce what caused the breakdown, but has issued an apology to all customers who have been affected, as well as the airlines.

A number of travel agencies were also affected by the disruption as they were unable to book airline tickets on behalf of their customers. The booking systems play a vital role at a time when airlines are encouraging as many customers as possible to complete processes such as reserving a seat and checking in over the internet before they turn up at the terminal.