The stuff reports that the longest flight in the world has been delayed. Qatar Airways had announced plans for its Auckland-Doha service to start in December, 2016.

At 14,539 kilometres, the flight would be the longest in the world and overtake the Auckland-Dubai service operated by Emirates.

The airline has delayed the launch of the world's longest direct flight until February due to the late delivery of Airbus A350 aircraft.

"We are minimising the impact on our passengers as much as possible and customers are being notified as we work on accommodating them on other flights that suit their travel needs," a spokeswoman said.

The flight was scheduled to start on December 3 using Boeing 777 aircraft, but those aircraft need to fill schedules reserved for the A350s. Flight time was expected to be between 17.5 hours and 18.5 hours.

Airline tracker site airlineroute.net said the daily service was now scheduled to begin on February 1, 2017 and reservations for flights in December and January closed on Monday.

The delay also means a reduction in Qatar Airways' services to Australia, as the airline offsets the delay by redeploying its existing fleet.

Qatar Airways has a fleet of 184 aircraft and its first Adelaide service touched down in Australia at the beginning of May.