The payload of 40 passengers and crew, majority employees, will undergo a host of medical checks and assessments.
Qantas said the direct New York-to-Sydney flight will be the first in history for a commercial carrier - and only the second from the British capital.
In preparation, Australian airline Qantas has announced three test flights, with 40 people traveling directly from London or NY to Sydney, to see how the human body copes with 19 solid hours in the air.
Other than crew, those in the cabin will mostly be Qantas employees taking part in testing. Since then, Boeing and Airbus have competed for the business, pitching planes they say could make the flights.
Qantas is closer to the "final frontier of aviation" with plans to fly the 10 500 miles between London and Sydney non-stop. That's why. Improvements in fuel efficiency have made ultra-long flights technically possible, but passenger and crew endurance needs some work. Qantas has previously said it would make a decision around the end of 2019.
Qantas has used features like a menu optimized for hydration and airport yoga studios to keep customers happy on longer flights.
The flights will be about 19 hours, the world's longest, and the roughly 40 people on board will be monitored by doctors to see how they cope with such a flight.
As part of the experiment, dubbed Project Sunrise, the pilots will also wear an electroencephalogram that tracks brain activity and alertness.
Qantas chief executive Alan Joyce said the flights in themselves were ground breaking and hoped to make a decision on trailblazing, long-haul flights to NY and London by the end of 2019.
Qantas" will operate the the health "research flights' with new 787-9 Dreamliners on the way to Australia out of Boeing's factory in Seattle.
"Flying non-stop from the East Coast of Australia to London and NY is truly the final frontier in aviation, so we're determined to do all the groundwork to get this right", Qantas CEO Alan Joyce said in a statement. They will be looking at how to minimize jet lag and how to create a comfortable long-haul atmosphere.
The world's longest commercial flight is 15,343km from Newark to Singapore and takes anywhere from 15 to 19 hours depending on winds. No commercial airline has done these kind of experiments before.