They are the futuristic jets that will soon fly us halfway around the world without a stopover.
That's if you can spend almost 20 hours confined to the cabin.
Qantas announced the purchase of 12 Airbus A350-1000s for their long-haul Project Sunrise flights from Sydney to London and New York beginning in 2025.
They will become the longest flights in the world, eclipsing the Singapore to New York haul of just over 17 hours.
Qantas boss Alan Joyce championed the purchase, delayed due to the COVID-19 pandemic, as the "last frontier and the final fix for the tyranny of distance".
So, what can the 238 passengers expect to see and how would a 20-hour flight work?
What is the A350?
Despite the fanfare, A350s have actually been flying in Australian skies for a few years.
Cathay Pacific uses the aircraft on its Melbourne to Hong Kong route and Qatar Airways, which has the largest fleet of A350s with 19, flies it from Sydney to Doha.
Internationally, A350s are being used on routes including Shanghai to Boston, Paris to Santiago and Manchester to Los Angeles.
The plane is 73 metres long and most airlines use a 3-3-3 seating configuration in economy.
The jet is competing with the Boeing 787 and 777X for market share.
Are they safe?
Qantas has partnered with the Charles Perkins Centre at the University of Sydney to investigate the impacts of ultra-long-haul flying on the human body.
Professor Steve Simpson was part of a research team that hooked passengers up with wearable health monitors in the week before and after a long-haul flight in a series of tests in 2019.
"You're not sleeping well, you're fatigued, you're at low pressure, all the sorts of physical things that happen from being in the air," Professor Simpson said of the findings.
Blood clotting in the legs, a condition called deep vein thrombosis (DVT), is a risk during long-haul flights.
But Professor Simpson said non-stop flights from Australia to London or New York were no more risky than current long-haul routes.
"There's no evidence that being in the air for 15 hours is any worse than being in the air for 19 hours," he said.
Qantas' A350 will feature a "wellbeing zone" where passengers from all classes can stretch their legs.
Professor Simpson said getting some physical activity, even if it was a five-minute stretch, was critical to minimising the health impacts of flying.
He added that cabin light, meal service, types of meals and stretching could all help passengers feel more refreshed at their destination.
How will the pilots go?
The plan has the backing of Tony Lucas, the president of the Australian and International Pilots Association.
"The fatigue of those sorts of 20-hour flights is certainly something that we're going to need to manage," he said.
"We'll work closely with Qantas and the Civil Aviation Safety Authority to make sure that we've got a good regime in place, I'm sure the Australian and travelling public expects their crews to be well rested."
Mr Lucas suggested changing the crewing arrangements could be one way of managing the issue of fatigue.
"Traditionally on long-haul flights we would operate the aircraft with one captain, one first officer and two second officers," he said.
"What we might find on these Sunrise flights, is that we operate with a slightly heavier crew, that is with one captain, perhaps two first officers and one second officer."
What do travellers think?
Shane O'Neil flew 18 hours from Darwin-London to see family in February.
"I felt better than if we had gone through Dubai, the total duration was less and we didn't have the anxiety of changing planes," he said.
Travellers at Sydney Airport gearing up for intercontinental flights on Monday were more hesitant.
Sophie Ball and Max Barker were jetting off to Vancouver for a working holiday.
"This is our longest one for both of us, 14 hours, so another six on top of that wouldn't be great," Mr Barker said.
Maile Loloa said a 20-hour flight sounded "a little bit crazy".
"I can't even last on a four-hour plane, so I don't know how its going to be on a 20-hour plane," she said.
