Flights back to normal after reservations system crash

Qantas was one of a number of airlines around the world affected when the global transaction processor experienced outages in one of its programs on Sunday.

The service provides check-in, load control and inventory services to its clients, which include Qantas and other international airlines.

Just before 4pm (AEST) a spokeswoman told reporters Qantas was back to business as usual at Sydney airport although some passengers would experience minor delays.

"Qantas is back on line. It's business as usual with just a few minor, or no, delays," she said.

Earlier on Sunday, domestic and international flights faced delays of about an hour after the travel transaction processor Amadeus experienced continuing outages in one of its programs.

A spokesman for Virgin Australia said only two of its long-haul flights were delayed as a result of the crash.

Short-haul international and domestic flights don't use Amadeus and weren't affected, he said.

Travellers took to the microblogging site Twitter to report chaos and long queues.

ABC personality Karl Kruszelnicki tweeted "big queues at Qantas domestic" and traveller Daz Martin reported "chaos at Adelaide airport Qantas check-in crashed".

A tweeter identified as Fake Qantas PR put a more topical spin on the situation, saying: "If you're flying #qantas today, please be patient. Our systems are down. And no, it's not because we didn't pay our carbon tax bill."