Turkish Airlines (Turkish: Türk Hava Yolları) (BİST: THYAO) is the national flag carrier airline of Turkey, headquartered at the Turkish Airlines General Management Building on the grounds of Atatürk Airport in Yeşilköy, Bakırköy, Istanbul.[5][6] As of February 2015, it operates scheduled services to 261 destinations in Europe, Asia, Africa, and the Americas, making it the fourth-largest carrier in the world by number of destinations.[7] With Istanbul Atatürk Airport being the main base, the Turkish carrier has secondary hubs at Esenboğa International Airport, Sabiha Gökçen International Airport, and Adnan Menderes Airport. THY has been a member of the Star Alliance network since 1 April 2008.