Northwest Airlines

Northwest Airlines, Inc. (often abbreviated NWA) is a subsidiary of Delta Air Lines, Inc., and was a major United States airline. It was headquartered in Eagan, Minnesota, near Minneapolis-St. Paul International Airport in the United States. Northwest had three major hubs in the United States: Detroit Metropolitan Wayne County Airport, Minneapolis-Saint Paul International Airport, and Memphis International Airport. Northwest also operated flights from a small hub in Asia at Narita International Airport near Tokyo and also operated transatlantic flights in cooperation with their partner KLM from Schiphol Airport in Amsterdam. It also had focus city operations at Indianapolis International Airport and Seattle-Tacoma International Airport.
As of 2006 Northwest was the world's sixth largest airline in terms of domestic and international scheduled passenger miles flown and the U.S.'s sixth largest airline in terms of domestic passenger miles flown. In addition to operating one of the largest domestic route networks in the U.S., Northwest carries more passengers across the Pacific Ocean (5.1 million in 2004) than any other U.S. carrier, and carries more domestic air cargo than any other American passenger airline. It is the only U.S. combination carrier (passenger and cargo service) operating dedicated Boeing 747 freighters. The airline, along with its parent company, Northwest Airlines Corporation and subsidiaries, operated under Chapter 11 bankruptcy protection which, in the United States, allows continued operation during the reorganization effort, not stopping flights as in the case in some countries. Northwest emerged from bankruptcy protection on May 31, 2007.
Northwest Airlines' regional flights were operated under the name Northwest Airlink by Mesaba Airlines, Pinnacle Airlines, and Compass Airlines. Its frequent flyer program was WorldPerks. Northwest Airlines' tagline was "Now you're flying smart." 
On April 14, 2008, Northwest announced it would be merging with Delta Air Lines, subject to regulatory review. The merger was officially completed on January 31, 2010.