THE world's longest non-stop commercial passenger flight has touched down safely in Sydney, Australia.

The 19 hour 16 minute test flight from New York was operated by Australian carrier, Qantas.

There were 49 people on board, including around 40 passengers.

The 16,200-km (10,066-mile) was trialling how being in the air for nearly an entire day affected pilots, crew and passengers.

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Next month, the company plans to test a non-stop flight from London to Sydney.

If successful, the company is expected to launch the routes on a full-time basis in 2022 or 2023.

Qantas already operates a 17-hour non-stop London to Perth, Australia flight.

The world's current longest, commercially-operated flight is Singapore Airlines' Singapore to New York flight, with an average duration of 18 hours 25 minutes.

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Passengers on the New York to Sydney test flight had their brainwaves and melatonin analysed during the journey, and were kept awake until six hours into the flight when they were served a high-carbohydrate meal and the cabin lights were dimmed.

Qantas Group CEO Alan Joyce said: "This is a really significant first for aviation. Hopefully, it's a preview of a regular service that will speed up how people travel from one side of the globe to the other."