"The difficulties are that has made the last three years so rewarding," said Allen, a father of four children.

He took lessons in Chinese and after three years in the country is able to speak the language reasonably well.

He can talk with people in Chinese, although he still cannot do a business deal in Chinese.

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"That's been a really important part of building relationships here," he said.

The man from South California has a deep understanding of the importance of relationships in China, something he will treasure when he leaves the country.

Boeing has regained top position in the Chinese market in recent years despite its competitors developing fast in the market.

Boeing delivered 168 aircraft to China in 2013, a 60 percent year-on-year rise. Airbus delivered133 airplanes.

"I would like to talk about deliveries, which are real, rather than orders," Allen told reporters when asked about the market situation.

However, it's not been plain sailing in China, Allen admitted frankly.

"The most difficult (time) was not a moment: It was a five-month period," he said.

In early 2013, the Boeing 787 Dreamliner experienced battery-related problems and aviation authorities in some countries ordered airlines to ground the jet until the problem was resolved.

The move affected deliveries to Chinese airlines, because Boeing was in the middle of completing validation-of-type certification for the airplane in China at the time.

"That was a tough time," Allen said.

It was also a busy time for him, because he had to communicate with every side involved, from the factory in Seattle to Chinese local authorities, airlines and banks providing financing.

Technical experts from Boeing were brought over to explain their solution to the problem.

The first Dreamliner was eventually received by a China operator in June 2013. By the end of the year, two Chinese airlines had received a total of 14 Dreamliners.

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