How Qantas plans to beat jet lag on the world’s longest 20-hour flight

For decades, airlines have focused on making long-haul flights more comfortable with bigger seats, better entertainment and improved meals.

Now, Australia’s Qantas believes the answer lies in something passengers cannot easily see: biology.

As the airline prepares to launch the world’s longest commercial flights between Sydney and London in 2027, lasting up to 20 hours nonstop, it is redesigning nearly every aspect of the journey around sleep science, human circadian rhythms and passenger wellbeing rather than traditional cabin luxury.

The initiative, known as Project Sunrise, will eventually connect Sydney directly with London and later New York using specially modified Airbus A350-1000ULR aircraft capable of flying for as long as 22 hours without refuelling. The aircraft are being fitted with additional fuel capacity while carrying only 238 passengers—far fewer than a standard A350—to improve comfort on ultra-long journeys.

According to researchers involved in the project, the greatest obstacle is not engineering but the human body.

Flying across seven to 16 time zones disrupts the body’s circadian rhythm, often leading to jet lag, fatigue and reduced alertness that can last for several days after arrival.

Peter Cistulli, professor of sleep medicine at the University of Sydney, who worked with Qantas on the project, said the airline has spent years studying how light exposure, meal timing and movement can help travellers adjust to a new time zone before they even land.

Instead of serving meals whenever passengers become hungry, cabin crews will follow carefully timed schedules designed to encourage wakefulness or sleep depending on the destination’s local time.

Lighting throughout the cabin will also change gradually, using colour and intensity to mimic sunrise and sunset in an effort to help reset passengers’ internal body clocks.

The aircraft’s interior has also been reimagined.

One of its most unusual additions is a dedicated Wellbeing Zone, where passengers can leave their seats to stretch, perform guided exercises or simply stand and move around during the flight.

Cabin designer David Caon said the airline originally explored ideas including exercise bikes and yoga areas before settling on a quieter relaxation space featuring soft, diffused lighting intended to reduce stress and encourage gentle movement.

Passengers will also benefit from increased legroom across cabins, while the reduced seating capacity allows more personal space than on conventional long-haul aircraft.

The concept is not entirely new.

Qantas began researching ultra-long-haul travel in 2019, operating experimental nonstop flights between New York, London and Sydney while monitoring passengers’ sleep patterns, alertness, food intake and movement with wearable technology.

The airline worked alongside sleep scientists, nutritionists and aviation specialists to determine how onboard routines could reduce the physical effects of spending nearly an entire day in the air.

According to Condé Nast Traveler, the early test flights examined everything from caffeine intake and meal composition to cabin lighting and exercise programmes, helping shape many of the features now planned for Project Sunrise.

Project Sunrise represents one of aviation’s most ambitious experiments in passenger wellbeing.

While nonstop services eliminate airport layovers and can shorten total journey times, they also require airlines to rethink how travellers eat, sleep and move onboard.

According to Airbus, the specially modified A350-1000ULR includes an additional 20,000-litre fuel tank and engineering changes that extend its range to almost 10,000 nautical miles, enabling nonstop flights previously considered impractical.

The Sydney-London service is expected to launch in October 2027 after aircraft deliveries were delayed, with Sydney-New York scheduled to follow. Qantas hopes passengers will be willing to pay a premium for avoiding stopovers while arriving feeling less fatigued than on conventional long-haul journeys.