Passengers were getting ready to board the world's longest flight on Thursday -- a marathon 19 hours in the air between Singapore and New York.

Two pilots, a special "wellness" menu and more than seven weeks' worth of film and television entertainment were expected to accompany travellers on the 16,700-kilometre (10,400-mile) journey to the Big Apple.

Singapore Airlines Flight SQ22 will use the long-range Airbus A350-900ULR, configured to carry 161 passengers -- 67 in business class and 94 in premium economy.

Singapore Airlines (File Photo: AFP)

For the flight crew -- which also includes two first officers and a 13-strong cabin contingent -- the work load will be broken up, the airline said, with every person getting a mandatory minimum four hours' rest.

But for passengers, the challenge will be what to do with all that down time up in the air.

For those not packing a weighty novel (or two), there will be 1,200 hours of audio-visual entertainment to choose from.

Dining options will include dishes the airline says have been selected to promote well-being in the skies, with organic dishes on the menu.

The cabin has higher-than-normal ceilings, larger windows and lighting designed to reduce jet lag -- all part of an effort to lessen the stresses that can accompany almost a day on a plane.

"Research has shown that hydration and food intake are important factors (to consider), such as avoiding foods that cause gas or bloating as well as excessive alcohol," Rhenu Bhuller, a healthcare expert at consultancy Frost & Sullivan, told AFP.

"The biggest concern is Deep Vein Thrombosis from a combination of sitting for too long and also from dehydration," said Gail Cross, an associate consultant at the National University Hospital in Singapore.