Qantas to start selling tickets next year for its New York to Sydney nonstop flight

Qantas Airways plans to start selling seats on its first nonstop between New York and Sydney next August, with flights set to launch in 2028, as the Australian carrier fills out the details for another marathon route with a special Airbus plane.

The route will take about 18 hours, which puts it close to what is currently the world's longest flight. The route that has that designation right now, nonstop service on Singapore Airlines from New York's John F. Kennedy International Airport to Singapore, can top 19 hours.

But Qantas is set to take the crown next fall when it debuts nonstops between London Heathrow and Sydney that take about 20 hours. Flight times vary based on direction and time of year.

Qantas CEO Vanessa Hudson told CNBC that the new flights come after strong demand for another ultra-long-haul route: its Perth, Australia, to London service, which is more than 17 hours and is flown on a Boeing 787 Dreamliner.

"What we have been able to learn from that is that there is absolutely a customer who wants this and is prepared to pay a premium for it," she said in an interview in New York, adding that travelers are trying to avoid having to connect in other airports.

The Qantas Airbus A350-1000 ULR, which stands for ultra-long range, will be equipped with first class, business class, premium economy and standard economy cabins. Those aircraft have an extra fuel tank for the trip.

Singapore Airlines, meanwhile, operates its New York to Singapore flight with only business class and premium economy seats.

As part of its ultra-long-haul program, which it calls Project Sunrise, Qantas spent years working with sleep scientists to study jet lag. Hudson said the carrier has looked at ways to minimize the effects of traveling long distances by using things like different lighting schemes so customers can get used to the time zone at their destination.