Singapore Airlines Limited (SIA; SGX: C6L) is the flag carrier airline of Singapore with its hub at Singapore Changi Airport. The airline uses the Singapore Girl as its central figure in corporate branding. The Singapore Airlines group includes many airline-related subsidiaries. SIA Engineering Company handles maintenance, repair and overhaul (MRO) business across nine countries, with a portfolio of 27 joint ventures, including with Boeing and Rolls-Royce. Singapore Airlines Cargo operates SIA's freighter fleet and manages the cargo-hold capacity in SIA's passenger aircraft. It has two subsidiaries: SilkAir operates regional flights to secondary cities, while Scoot operates as a low-cost carrier. Singapore Airlines was the launch customer for the Airbus A380, the world's largest passenger aircraft. It ranks amongst the top 15 carriers worldwide in terms of revenue passenger kilometers, and is ranked 10th in the world for international passengers carried. Singapore Airlines was also the launch customer for the Boeing 787-10 and started scheduled flight to Osaka.