Passengers aboard Qantas flight 7879 departed from London early on Thursday morning and arrived in Sydney a little after noon on Friday – 19 hours and 19 minutes in the air.
So how do you keep people on board from going crazy – or getting deep vein thrombosis – while they accumulate for so long?
The Australian airline's approach to the 11,000-mile flight was to design the meals and lighting carefully, get passengers out of their seats and focus on the remarkable: two sunrises in one day.
In addition to Sydney, Qantas is researching a number of new direct flights that would be longer than any currently operating, including from New York and London to Melbourne and Brisbane. And so were the 52 people on board – largely employed by the airline, along with some journalists – guinea pigs.
Last month, Qantas landed the first non-commercial direct flight from New York to Sydney. That flight took 19 hours, 16 minutes. The carrier says that the flight saved passengers three hours during normal routing, which includes a stop.
Jet-team researchers at the University of Sydney implemented a number of flight strategies related to light, food and exercise.
To help the body adapt to the time difference, the light in the cabin was correlated with Sydney time as soon as the flight took off. So even though the plane started at 18 in London, dinner was served and the lights were soon turned off.
Meals were designed to give specific effects. The dinner was a carbohydrate steak sandwich, light on spice, intended to calm passengers to sleep. Drinks were also offered – in the previous nonstop test flight between New York and Sydney, 38% of passengers said they drank alcohol to speed up sleep (although alcohol can be particularly dehydrating on such extended flights).
And the passengers were guided to practice: walking in a circle around the plane and doing stretches. That part was easier than on a regular flight, since the plane was mostly empty.
To test the impact of flight and measure effort to make it less taxing, tested passengers wore activity monitors, kept logs of how they felt and played a "whack-a-mole" game on an iPad to test their reaction time and attention.
Pilots and cabin crew carried activity monitors and kept Sunday diaries. Pilots wore EEG monitors to track their brain activity and alertness, and provided urine samples so that their melatonin levels could be used to indicate their body clock status.
The London-Sydney route was flown commercially once before, along another road in 1989, with only 23 passengers. The longest flight at present is Singapore Airlines nonstop from Singapore to Newark, which takes 18.5 hours.
The researchers' tactics seemed to help aboard the new Boeing 787-9 aircraft.
"I feel really good," test passenger Andy Chevis told Reuters during the descent. "Probably much better than I normally would at this time during the flight."
Unfortunately, it seems that the most advanced science cannot change the most human of desires: the desire to land.
At hour 17, CNN's Richard Quest reported, there was "a distinct feeling that people are anxious to see the end of the flight. They want as soon as possible."
Qantas began offering a direct flight between London and Perth last year; The company says the route has won its highest level of customer satisfaction and has made its service to London profitable for the first time in ten years. The cost of such an upcoming flight is $ 1,087. It is not clear what pricing will be for the routes the airline tests now.
The airline says it expects to decide whether to proceed with the super-long routes by the end of 2019, with the goal of launching direct lines until 2022.