China Southern Airlines (CZ)'s seventh Boeing 777-300ER aircraft has completed its first test flight at Paine Field Airport (PAE) after painting special SkyTeam colors in Portland, according to tweets posted by the airport.

The new 777-300ER aircraft, Registration B-2049, is also the seventh aircraft featuring the SkyTeam livery following Airbus 330-200 (B-6528), A330-300 (B-5928, B-5970), A320-200 (B-1697, B-1696) in service and 777-200 (B-2056) in storage. According to a source familiar with the matter, China Southern is scheduled to take delivery of the 777-300ER at Guangzhou Baiyun International Airport on Dec. 19, after a delivery ceremony in Seattle on Dec. 17.

In late November, China Southern's 777-300ER aircraft left PAE on a B1 flight to Portland for painting the SkyTeam livery. The first test flight, known as B1 flight conducted by Boeing test pilots, was part of a series of work that the manufacturer performs before handing over the airplane to the airline.

On Dec. 1, the aircraft B-2049 returned to Paine airport and conducted the first flight after painting. Before returning to the flight line, the aircraft performed a RTO - reject take off, according to a YouTube video released by OwnsGermany.

China Southern has 10 777-300ERs on order, all of which will be delivered in 2014-2016. The first Boeing 777-300ER (B-2007) joined the fleet of China Southern on Feb. 26, 2014. Currently, the Guangzhou-based carrier has taken delivery of six 777-300ERs, which are mainly deployed on long-haul routes to New York, Singapore, London, and Los Angeles.

The Boeing 777 is the world's most successful twin-engine, long-haul airplane. The 777-300ER extends the 777 family's span of capabilities, bringing twin-engine efficiency and reliability to the long-range market.

China Souhtern's 777-300ER features four distinct cabins with 309 seats - 4 in first class, 34 in business class, 44 in premium economy class and 227 in economy class.