Shenzhen Airlines is a domestic and international airline headquartered in Shenzhen Bao'an International Airport in Bao'an District, Shenzhen, Guangdong, People's Republic of China. With a fleet of over 100 Narrowbody aircraft (a mix of A320 series aircraft and various 737 types), Shenzhen Airlines is the fourth largest domestic carrier with around 7% of seat capacity and flights. The carrier operates a total of 137 domestic airport-pairs involving 58 Chinese airports, plus nine international routes. In 2010, the airline carried 16.5 million passengers, up 9% on the previous year. On 6 July 2011, Shenzhen Airlines was formally accepted as a future member of Star Alliance. On 29 November 2012 the airline officially joined Star Alliance becoming the alliance's second member in China following the departure of Shanghai Airlines in 2010. Shenzhen Airlines is one of the several airlines discovered to have employed a large number of pilots with falsified flight experience and qualifications. The authorities warn they cannot be sure all fake pilots have been rooted out.