Singapore Airlines Limited is a Singapore-based company. The principal activities of the Company consist of passenger air transportation. The Company and its subsidiaries are engaged in passenger and cargo air transportation, airport terminal and food operations, engineering services, training of pilots, air charters and tour wholesaling and related activities. The Company operates in three business segments: airline operations, airport terminal and food operations, and engineering services. The major subsidiary companies of the Company are Singapore Airport Terminal Services Limited (SATS), SIA Engineering Company Limited (SIAEC), Singapore Airlines Cargo Pte Limited (SIA Cargo) and SilkAir (Singapore) Private Limited (SilkAir). In September 2009, the Company held 0.6% interest in Singapore Airport Terminal Services.