NEW YORK (FOX 5 NY) - How long is too long to be on a flight?  Qantas is going to see if a nearly 20-hour flight is possible.  The airline is going to be testing a direct flight from New York to Sydney, Australia.

The ultra-long-haul "ghosts flights" will carry airline staff to test the effects on their bodies before deciding whether to sell seats to passengers.

The airline will use Boeing 787-9s Dreamliners for the tests in October, November, and December.

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The flights form part of planning for Project Sunrise – Qantas' goal to operate regular, non-stop commercial flights from Australia to London and New York.

This will represent the world's first flight by a commercial airline direct from New York to Sydney and only the second time a commercial airline has flown directly from London to Sydney.

"Flying non-stop from the East Coast of Australia to London and New York 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.

Each flight will have a maximum of 40 people, including flight crew, in order to minimize weight and give the necessary fuel range.

People in the cabin – mostly Qantas employees – will be fitted with wearable technology devices and take part in specific experiences at varying stages of the approximately 19-hour flights

Scientists and medical experts will monitor sleep patterns, food and beverage consumption, lighting, physical movement and inflight entertainment to assess the impact on health, wellbeing, and body clock.