Northwest began on October 1, 1926, flying mail between Minneapolis/St. Paul and Chicago. Its passenger service began in 1927. On July 15, 1947, Northwest pioneered the Great Circle route to Asia, with service to Tokyo, Seoul, Shanghai, and Manila. Northwest became a wholly owned subsidiary of Delta Air Lines on October 29, 2008. The airline operates a fleet of aircraft including Boeing 747s, and 757s, McDonnell-Douglas DC-9s and Airbus A330s, A320s and A319s. Northwest also is one of the world's largest cargo airlines, operating a dedicated fleet of 14 B747 freighters. It is the only U.S. combination carrier (passenger and cargo service) to operate dedicated 747 freighters.