Northwest Airlines was a major carrier in the United States until it was acquired by Delta Air Lines in 2008. Some synonyms for "Northwest Airlines" could be "NWA," "Northwest," or simply "Northwest Airways." In the aviation industry, the airline was recognized for its presence in Asia, particularly in Japan. It had significant operations at both Tokyo's Narita International Airport and Osaka's Kansai Airport, among others. Additionally, Northwest Airlines was known for its "WorldPerks" frequent flyer program and its hub operations in Minneapolis/St. Paul, Detroit, and Memphis. While the airline no longer exists as a separate entity, its legacy lives on through Delta Air Lines, which acquired many of its assets and routes.