sentences:  In April 2005, Murray Air and its sister company, Murray Aviation, merged operations under Murray Air’s newly acquired Part 121 certificate.In December 2008, after the airline was acquired by National Air Cargo, Murray Air changed its name to National Airlines, and operates under the National Air Cargo Group, Inc. umbrella.National Airlines used to operate scheduled charter passenger flights from Oakland County International Airport to Kokomo Municipal Airport in Kokomo, Indiana, Chicago Rockford International Airport in Rockford, Illinois, Spirit of St. Louis Airport in St. Louis, Missouri, and Toronto Pearson International Airport in Toronto, Ontario, Canada (with some flights making intermediate stops at Willow Run Airport in Ypsilanti, Michigan) for Chrysler Corporation employees and also sold seats on those flights to the general public.