Air Nostrum, Líneas Aéreas del Mediterráneo is a Spanish Airline with the IATA code: YW is an independent regional carrier with their main operating base in Valencia Spain with additional hubs in Madrid and Barcelona that also operates as a franchisee of Iberia as Iberia Regional. They began operations on the 23 May 1994 and have a fleet of ATR and Bombardier aircraft. As of 1st September 1999, Air Nostrum received access to the oneworld Airline Alliance as an affiliate member. The Air Nostrum schedule has been designed to enable the greatest amount of connections for Iberia and other oneworld carriers via Madrid-Barajas Airport Terminal, T4. On the majority of Air `Nostrum ATR served flights they operate a two-class class service (economy and business). An interesting point to note that on the ATR-72 the business class is at the back of the plane which is near the exit.