What is the impact of the longest flight on the health of passengers?

Qantas announced that it would conduct three test flights between London and New York to Sydney in about 19 hours to see the impact of sitting in the plane for the health of the passengers.

According to the CNBC, the Australian airline announced that the three flights would carry a maximum of 40 people, including crews and research teams on board, where they would test factors such as sleep patterns and food consumption, so "to evaluate the impact on health". Well-being and biological clock. "
Passengers, most of whom are staff members, will receive wearable devices for flight testing, Qantas said.
The airline said it had already done test flights along its direct route between Perth and London.
The company plans to use Boeing 787 9s to perform flights as part of its Sunrise project, but said the final decision regarding flight operations would be taken by the end of the year.
"In fact, it's the first time that a commercial airline is making non-stop flights between New York and Sydney, and it's only the second time it's flying from London." Qantas CEO Allen Joyce told CNBC on Thursday. In Sydney.
He added that the test allowed us to manage the risks of "fatigue, impact on passengers and employees and help development".
The airline hopes to operate direct flights between New York and Sydney, London and Sydney by 2022.