US Airways (formerly known as USAir) was a major American airline that ceased to operate independently when the Federal Aviation Administration granted a single operating certificate (SOC) for US Airways and American Airlines on April 8, 2015. Publicly, the two carriers appeared to merge when their reservations systems and booking processes were merged on October 17, 2015; however, other systems were still separate at that time. The airline had an extensive international and domestic network, with 193 destinations in 24 countries in North America, South America, Europe and the Middle East. The airline was a member of the Star Alliance, before becoming an affiliate member of Oneworld in March 2014. US Airways utilized a fleet of 343 mainline jet aircraft, as well as 278 regional jet and turbo-prop aircraft operated by contract and subsidiary airlines under the name US Airways Express via code sharing agreements.