Updated 05-06-2019 12:50 (UTC+2).

Major airlines around the globe are pushing the limits and capabilities of next-generation aircraft by increasingly targeting long-haul and super-haul flights across continents. One such ambitious project is underway for Qantas – Australia’s national carrier is expecting Airbus and Boeing to present their final offers for the ultra-long-haul aircraft that would be operated on the planned Sydney-London route, set to be the world’s longest commercial flight when it is launched in 2023. The ultra-comfortable passenger experience boasted about by the airline’s CEO, on the other hand, may not come to fruition.

Last year, on May 24th, Qantas launched what it hailed as “historic” non-stop service between Perth and London. The over 9,000 mile (14,500 km) flight operated by Boeing 787-9 Dreamliner took just over 17 hours to complete. But this service was just a warm-up before the airline rolls-out direct flights from Sydney to London and New York.

In 2017, Qantas’ CEO Alan Joyce announced the airline is targeting direct flights from the east coast of Australia to the two major cities by 2022, Bloomberg reported at the time. It was planned that the Sydney-London service would take 20 hours, 20 minutes, while the Sydney-New York route would be covered in 18 hours, 7 minutes.

Other possible routes envisioned at the time included Paris, Rio de Janeiro and Cape Town, linking Australia directly to hubs in the Americas, Europe and Africa.

To make the super-haul flight viable, Joyce turned to the world’s leading aircraft manufacturers – Airbus and Boeing. Latest report from Aviator.aero indicates the airline has asked the plane makers to present their “best and final offer” for long-haul jetliners that would be capable of flying the up to 21-hour, over 10,550 mile (16,979 km) -long non-stop flight between Sydney to London by August 2019.

The choice is between the ultra-long-range Airbus A350 and the Boeing 777X, various media sources indicate; and if “everything else comes together”, the final decision to place an order would be made by the end of the year, Joyce told CNBC.

As is the case, the main challenge for the plane makers is range and capability: the manufacturer would have to configure a jetliner that could fly about 300 passengers farther than any regular service to date. For instance, Qantas’ Boeing 787-9, operating on the Perth-London route, is configured with a total seat count of 236 passengers.

“Farther” also means beating Singapore Airlines (SIA1) (SINGY) (SIA), which made headlines last year when it re-launched its non-stop Singapore-New York service, becoming the world’s longest commercial flight today. Launched on October 11, 2018, the inaugural flight lasted 17 hours, 52 minutes covering some 9,500 miles (15,300 km).

SIA’s service is operated by one of the carrier’s Airbus A350-900ULR (Ultra Long Range) jets, a variant of the A350 XWB Family aircraft ordered specifically for such long distance flights. Configured in a two-class layout, the jetliner can seat 161 passengers.

Another milestone in aviation took place on Thursday October 11th when an Airbus A350-941 departed Singapore's Changi Airport (SIN) just before midnight, embarking on a journey that would last almost

According to Forbes estimations, on average, SIA’s Singapore-New York service covers 9,534 miles taking up to 18 hours, 30 minutes. The introduction of this route dethroned Qatar Airways’ Auckland-Doha service as the world’s longest flight. Operated by Boeing 777-200LR (Long Range) the Qatar Airways’ 9,032 mile-long route takes 17 hours, 50 minutes.