Last week, Air India claimed it had launched the world's longest flight - though this was purely thanks to its choice of routing. The mileages quoted by airlines are for the "Great Circle" route, the shortest distance between the two cities. In practice, the actual distance flown is significantly longer for reasons of geo-political sensitivity or, more usually, wind patterns.

 "Flying west means facing strong headwinds, that decrease an aircraft's actual ground speed, and flying east means getting string tailwinds, which do the opposite."

But according to the traveller.com.au, the Air India's record will not stand for long, however as Singapore Airlines prepares to reinstate its Singapore-New York route that will cover 16,500 kilometers in 19 hours.

At present the two most distant cities linked by a non-stop flight are Dubai and Auckland, 8,824 miles apart. Emirates flies the Airbus A380, the world's biggest passenger jet, daily between the two cities.

The independent.co.uk says that from February 1next year, its rival Qatar Airways will also fly non-stop to New Zealand's largest city. As the Qatari capital is over 200 miles further away, the new Doha to Auckland link will take the prize.

Eight of the longest 10 links begin or end in the US, and seven start or finish in the Gulf. Three serve Australasia (two to Auckland, one to Sydney). Europe and Asia are unrepresented, with Africa represented only by Johannesburg.

Qantas is considering the first non-stop flight between Europe and Australia, with a link connecting London and Perth. Such a route would become the second-longest worldwide, with a direct distance of 8,991 miles. But the Australian airline is guarded about the possibility.

Several ultra-long-haul routes have been touted but failed to materialise.

Ultra-long-haul flights are extremely expensive to operate, and depend on relatively cheap oil for profitability. They burn a disproportionate amount of fuel per mile, because of the volume that needs to loaded to sustain the journey, and demand heavy crew resources.