At 21 hours and covering almost 17,000 kilometers, a direct flight from Sydney to London would be the longest in the world.
Travelling this far without a break is an attractive proposition for airlines. The technology’s ready to go, with manufacturers saying they’ve built planes capable of the journey. And Australia's Qantas Airways has announced plans to fly the route, saying it would help it compete with one-stop rivals, while charging a premium.
So the industry’s all set to take to the skies for the best part of a day – but are pilots and passengers on board with the idea?
Sharing the load
Airlines are keen to help passengers adjust to being in the air for so long.
Last year, Qantas completed the first scheduled non-stop flight between Australia and the UK, flying 17 hours from Perth to London. Ahead of the flight, the airline partnered with researchers at the University of Sydney to design an in-flight environment that takes the edge off the long journey time.
They focused on everything from the menu and timing of the cabin service, to lighting and temperature, in order to design an environment that would help alleviate jet lag and boost well-being.
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But what about the crew? Ultra-long-haul flights require four pilots to share the workload. On-board bunks allow them to rest while their colleagues fly the plane. But it’s not without risks, especially if pilots aren't able to fall asleep in-flight.
In January, the Australian Transportation Safety Board published a study in which 60% of long-haul pilots said they felt moderate- to severe fatigue at the end of their most recent flight. Although pilots can refuse to fly if they are tired, the report found most believed it would harm their careers to do so.
The length of shifts could be a barrier, too. Australian pilots are restricted to working a maximum of 20 hours a day, including pre- and post-flight checks on the ground. The Sydney-London route is expected to require pilots to be on duty for up to 23 hours.
And that takes things to “another level again”, according to the association that represents Qantas pilots.
“The technological change is obviously there but the human physiological side hasn’t changed since the Wright brothers flew,” Mark Sedgwick, head of The Australian and International Pilots Association, recently told Reuters.
“We really need to understand the effects on human performance on the flight deck of these ultra-long range flights,” he added.
The union and Australia's aviation regulator are jointly sponsoring research by Melbourne’s Monash University to monitor sleep patterns of pilots flying the Perth-London route, which uses Boeing’s 787 Dreamliner plane.
Meanwhile, a union representing Qantas cabin crew has already called for longer rest periods between flights on the 17 hour Perth-London route, which they said involved on-duty periods of 19 hours for the flight attendants aboard.
Ultra-long-haul crews on Singapore Airlines - whose Singapore to New York flight is currently the world’s longest at almost 18 hours - include two captains and two first officers. Crews on Qantas’s Perth-London service include a captain, a first officer and two second officers not qualified to handle take-offs and landings.
Flights of the future
The growing number of longer, direct flights is part of a move away from using hub airports where passengers change planes to complete their journeys, or face stopovers while planes are refuelled.
Passenger reaction has been generally favourable. One traveller told tripadvsor.com of his London to Perth non-stop journey: "Loved this flight. Can't stand all the getting off, wandering aimlessly around an airport in the middle of the night then having to go through security queues again before the next long flight."
As well as saving time for passengers, direct flights by more fuel-efficient jets are also better for the environment.
The challenge for the airlines is how to embrace the benefits of the latest technology while ensuring their pilots can stay awake.