Milwaukee, WI MKE to Atlanta, GA ATL flight with United

Piedmont Airlines is an American regional airline and a wholly-owned subsidiary of the American Airlines Group. Headquartered in Salisbury, Maryland, Piedmont operates American Eagle flights, staffing, operating, and maintaining aircraft for American Airlines.The airline traces its roots back to Henson Aviation, founded in 1931, and was rebranded as Piedmont Airlines in 1993. Today, Piedmont operates a fleet of Embraer ERJ 145 regional jets, with nearly 400 daily departures to over 50 destinations, primarily throughout the eastern United States. Its main hubs include Philadelphia International Airport and Charlotte Douglas International Airport. Piedmont also provides ground handling and customer service for airports in the northeastern and western United States.

PSA Airlines is an American regional airline and a wholly-owned subsidiary of the American Airlines Group, operating exclusively on behalf of American Airlines under the American Eagle brand. Headquartered in Charlotte, North Carolina, PSA Airlines operates over 800 daily flights to nearly 100 destinations across the United States. The airline maintains an all-jet fleet consisting of Bombardier CRJ700 and CRJ900 regional aircraft. With a team of over 5,000 employees, PSA Airlines plays a significant role in connecting smaller cities to major hubs within American Airlines' network.

Republic Airways is a major regional airline in the United States, operating as a subsidiary of Republic Airways Holdings. It provides scheduled passenger service for American Airlines (as American Eagle), Delta Air Lines (as Delta Connection), and United Airlines (as United Express) using a fleet of Embraer 170 and 175 regional jets. Headquartered in Indianapolis, Indiana, Republic Airways operates over 900 daily flights to more than 80 cities across the U.S. and Canada. The company is known for its large fleet of Embraer E-Jets and its state-of-the-art training facilities. In April 2025, Republic Airways Holdings announced its acquisition of Mesa Air Group, which is expected to create the second-largest regional carrier in the U.S.

Frontier Airlines is a major American ultra-low-cost carrier headquartered in Denver, Colorado, operating flights to over 120 destinations across the United States, Caribbean, Mexico, and Central America. Known for its "Low Fares Done Right" philosophy, Frontier focuses on offering affordable travel by allowing passengers to choose and pay only for the services they need, such as seat selection or baggage. The airline is also recognized for its commitment to fuel efficiency, claiming to be "America's greenest airline" due to its modern, lightweight aircraft and operational practices. A distinctive feature of Frontier is the animal featured on the tail of each aircraft, highlighting North American wildlife.