At 19 hours, this flight holds the record for the longest nonstop journey. But how will the human body fare during such an extensive trip?

Nonstop flights connecting Australia's east coast with London or New York could soon be a reality. In preparation, Australian airline Qantas has announced the first of three trial flights, set to depart this Friday.

The goal? To study how the human body handles 19-20 consecutive hours in the air.

This groundbreaking test flight, operated by a Boeing 787-9 Dreamliner, departs New York on October 18 and is expected to land in Sydney on Sunday morning, local time.

Onboard will be 40-50 'test' passengers, along with pilots, crew, scientists, and medical specialists.

The majority of passengers on the test flights will be Qantas employees, though six volunteer Qantas Frequent Flyers will also be aboard.

Qantas has already set its sights on launching direct flights between London, New York, and three major Australian cities – Sydney, Brisbane, and Melbourne – by 2023.

Bjorn Fehrm, an aeronautical and economic analyst at Leeham News, explains to Dinogo Travel that there are several reasons why travelers prefer the ultra-long-haul flight over the more common two-part journey with a stop in Dubai or Singapore.

There are no layovers, no extra customs checks, and no transfer hassles, he adds.

“You can plan your flight overnight, and still have a full day ahead of you when you arrive,” Fehrm says. “It’s likely to appeal to business travelers.”

If the 19-hour flight becomes a reality, passengers can expect to pay a higher fare.

“It’s more economical for the airline to operate two separate flights,” Fehrm explains. “However, some travelers are willing to pay the premium for a single nonstop flight.”

The next test flight is scheduled for November, from London to Sydney, followed by another New York to London flight before the year ends.

Once the test flights are completed, the new aircraft will be deployed for commercial service.

Researchers from Sydney University's Charles Perkins Centre, Monash University, and the Alertness Safety and Productivity Cooperative Research Centre – a program funded by the Australian government – will study the effects of the long-haul flight on passengers and crew.

Passengers in the main cabin will wear tracking devices, and experts from the Charles Perkins Centre will assess how factors such as lighting, food, movement, sleep, and entertainment affect their health, wellbeing, and circadian rhythms.

Passengers have been asked to keep a daily log leading up to the flight and for two weeks afterward, detailing their feelings and how they manage jet lag.

Pilots and cabin crew will also be monitored and asked to maintain sleep journals. Cameras will be installed in the cockpit to track pilot alertness.

“People experience jetlag very differently, and we need more research into the causes of jetlag and travel fatigue so that we can minimize the effects of long-haul flights,” says Professor Stephen Simpson, academic director of the Charles Perkins Centre at the University of Sydney, in an interview with Dinogo Travel.

“We still have much to learn about how various factors – such as nutrition, hydration, exercise, sleep, and light – work together for the greatest benefit,” he adds.

Simpson states that the research conducted on these test flights will provide valuable insights into how long-haul flights affect both passengers and crew, benefiting the fields of science and aviation.

Monash University researchers will focus on the flight crew, measuring their melatonin levels before, during, and after the flights, and analyzing brainwave data from electroencephalogram devices worn by the pilots.

This data will be shared with the Civil Aviation Safety Authority to assist in shaping regulatory standards for ultra-long-haul flights, according to a Qantas press release.

“Ultra-long-haul flights raise many important questions regarding the comfort and wellbeing of passengers and crew,” says Alan Joyce, Qantas Group CEO, in the release.

“These flights will provide crucial data that will help answer these questions,” he adds.

“For passengers, the key is minimizing jet lag and creating an environment where they can look forward to a relaxing, enjoyable flight. For the crew, it’s about leveraging scientific research to identify the best moments to stay alert during their duties and ensure they get enough rest during their breaks on these flights.”

Dr. Eileen McNeely, co-founder and director of the SHINE initiative at Harvard T.H. Chan School of Public Health, and an instructor in environmental health, tells Dinogo Travel that the health risks for passengers on ultra-long-haul flights are similar to those on shorter flights, but amplified.

“The stressors on the body will still be present, but they will last much longer,” McNeely explains.

“Passengers may experience hypoxia, dehydration, muscle aches from prolonged immobility, exposure to loud noise, jet lag, cosmic radiation, and potential cabin air contaminants. These factors are even more concerning for passengers with pre-existing health conditions.”

However, McNeely notes that advancements in aircraft design – particularly lighter, more efficient planes – have improved environmental conditions, making these ultra-long-haul flights more bearable for passengers.”

Higher cabin pressures, greater humidity, and quieter engines are expected to improve the overall experience, she notes.

Nevertheless, McNeely raises concerns about limited mobility, advising passengers to get up and move around the cabin regularly, and to stay hydrated – avoiding alcohol due to its dehydrating effects.

“If you're over 60 and have heart or lung conditions, consult a doctor for a medical evaluation, including oxygen saturation tests, in case you need supplemental oxygen during the flight,” she adds.

As for the cabin crew, McNeely recommends ongoing health monitoring due to their heightened exposure to cosmic radiation and noise, as well as ensuring they get adequate rest before, during, and after their shifts.

For some, the idea of a 19-hour nonstop flight may seem daunting and overwhelming.

“In previous generations of aircraft, it was highly doubtful that such long flights would be practical or economically viable for airlines,” Fehrm tells Dinogo.

If this flight becomes a reality, it’s unlikely to revolutionize the aviation industry, Fehrm notes, pointing to the already existing 17-hour flights from Singapore to New York operated by Singapore Airlines.

“There are 20,000 aircraft flying worldwide every day, and only nine are doing these ultra-long flights,” he explains.

“This type of flight is an outlier, catering to a very small, elite group – it’s a prestige project,” he says. “But in certain situations, it absolutely makes sense, and in those cases, it’s worth the cost.”