The Boeing 787-9 Dreamliner, operating as QF7879, will take off on Thursday morning London time and land in Sydney on 11.45am on Friday AEDT.

The test flight, as part of Qantas's Project Sunrise, will carry just 40 people, including crew, to the other side of the world in approximately 19 hours.

A Dreamliner can usually carry between 230 and 300 people depending on its interior set-up.

Currently it is impossible to fly a plane at full capacity of both passengers and cargo from cities on the east coast of Australia to London without stopping to refuel.

It is possible to fly non-stop from London to the city of Perth in Western Australia as it is 2575km closer.

Despite vowing to slash carbon emissions and reach net zero by 2050, the Australian airline is testing the viability of the London to Sydney route as a regular commercial flight.

The airline said all carbon emissions from Thursday's take-off will be fully offset.

Those on board will be mostly Qantas employees and will be fitted with monitors to track their sleep patterns, food and drink intake, lighting, physical movement and in-flight entertainment.

The data will be assessed by researchers from the Charles Perkins Centre, a medical institute at the University of Sydney, to assess the impact of the flight on their health, wellbeing and body clock.

A team from Melbourne's Monash University will work with pilots and crew to monitor melatonin levels before, during and after the flight. Melatonin is the hormone that regulates sleep cycles.

Pilots will wear a device that tracks brain wave patterns and monitors alertness, Qantas said, to gather data on the best work and rest patterns for long-haul services.

The airline said the data on crew wellbeing and alertness will be shared with Australia's Civil Aviation Safety Authority to inform future regulations for ultra-long haul flights.

Qantas will also gather general feedback from passengers on food choices, stretching and wellbeing zones and in-flight entertainment.

The airline's chief executive Alan Joyce said previously: "Ultra-long haul flying presents a lot of common sense questions about the comfort and wellbeing of passengers and crew.

"These flights are going to provide invaluable data to help answer them."

It will be the second aircraft to fly the route non-stop, the first touched down in August 1989. A Boeing 747-400 was used then and carried no passengers, only crew. The plane is now at an Australian museum.

Qantas did fly a Dreamliner non-stop from New York to Sydney last month as part of Project Sunrise, although the route is around 1600km shorter.

It is due to make a final decision on the viability of Project Sunrise as a commercial flight route by the end of the year.

Australian Associated Press