By Max Duncan

CHENGDU, China (Reuters) - A pair of pampered giant pandas took off from China for Scotland on Sunday, with cabin crew on hand to calm their nerves and cater to their every need.

Tian Tian and Yang Guang - whose names in English are Sweetie and Sunshine - were lifted gently on board a plane in custom-built containers at Chengdu airport in China's southwestern Sichuan province.

"There are four crew members, two attendants, one veterinarian and one cargo handler, and they'll be taking very close care (of them) just like first class passengers on any airline," said Paul Cassel of FedEx.

"All of us will be able to go back and look after them, make sure that they're happy and secure and that their ride is secure, just like on any passenger airline."

Veterinarian Tang Chunxiang said he was worried about the pandas' nerves and fear of flying.

"They might get air sick, they may get a bit dizzy on the plane," he said. "...if there is any problem, we have brought some simple medicine."

The eight-year-old pair, who have been raised at the Giant Panda Conservation and Research Centre in Ya'an, Sichuan, will become Britain's first pair of breeding pandas in 17 years.

Iain Valentine, director of conservation and research at the Royal Zoological Society of Scotland, was pleased that five years of negotiation with the Chinese authorities had finally paid off.

"This is the exciting bit, this is the bit I have been waiting for a very long time," he said. "It's just lovely to see them now safely on the plane. And now we're on to the next bit of the journey,"

Since the 1950s, China has given away pandas as gestures of goodwill in what has come to be known as "panda diplomacy."

Modern China gave its first pair of giant pandas to Britain in 1974.

Tian Tian and Yang Guang won't go on display at Edinburgh Zoo for at least a week, until they have settled in to their new surrounds.

They will remain there for ten years, after which they, and any young they have, will return to the motherland.

Considered a national treasure, the giant panda is seen as having come back from the brink of extinction, but remains under threat from logging, agriculture and rapid urbanization.

There are an estimated 1,600 living wild in China, almost all in Sichuan. Around 300 are in captivity around the world, the vast majority of them inside China.

Pandas are notoriously difficult to breed because females ovulate only once a year and can only become pregnant during a two- or three-day period.

(Additional reporting by Samuel Shen; Editing by Nick Macfie)