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. These flights were operated by Saab 340 and BAe Jetstream 31 propjet aircraft in 30-seat and 19-seat configurations, respectively. This service is no longer operational.