London Heathrow Airport LHR to O'Hare International Airport ORD flight with British Airways

United Airlines, established in 1926, is a major U.S. airline headquartered in Chicago, Illinois. Operating an extensive domestic and international network, United serves more destinations than any other airline, connecting travelers across six continents. The airline's eight hubs include Chicago–O'Hare, Denver, Houston–Intercontinental, Los Angeles, Newark, San Francisco, Washington–Dulles, and Guam. As a founding member of the Star Alliance, United offers a comprehensive range of services, including regional flights through United Express, catering to both leisure and business travelers. The airline is committed to sustainability, investing in sustainable aviation fuel and innovative technologies to reduce its environmental impact.

British Airways (BA) is the United Kingdom’s flag carrier airline with headquarters in London near its main hub at London Heathrow Airport (LHR). BA is the second largest UK-based airline in terms of fleet size and number of passengers carried. Known as a full-service global airline, British Airways offers year-round low fares to destinations worldwide and flies to and from centrally-located airports. Its extensive global route network includes more than 170 destinations in nearly 80 countries throughout Europe, North America, South America, Asia, Africa and Australia. syn p British Airways (BA) is the flag carrier airline of the United Kingdom with its headquarters in London near its main hub at London Heathrow Airport (LHR). Known as a full-service global airline, BA offers low fares year-round to destinations around the globe and flies to and from centrally-located airports. Its extensive global route network includes more than 170 destinations in nearly 80 countries throughout Europe, North America, South America, Asia, Africa and Australia. BA is also the second largest airline based in the UK in terms of its fleet size and number of passengers carried.

SAS, or Scandinavian Airlines, is the national airline of Denmark, Norway, and Sweden, headquartered in Solna, Sweden. Founded in 1946, it emerged from a merger of the three countries' national carriers to handle transatlantic operations. SAS operates extensive regional services within Scandinavia and Europe, as well as international flights to Asia and North America, with primary hubs in Copenhagen, Stockholm, and Oslo. As of July 2024, SAS, including its subsidiaries SAS Link and SAS Connect, operates a fleet of 133 aircraft to 130 destinations. SAS joined SkyTeam on September 1, 2024, after leaving Star Alliance.

American Airlines is one of the largest airlines in the world, connecting travelers to hundreds of destinations across the United States, Latin America, Europe, Asia, and beyond. Operating from major hubs such as Dallas/Fort Worth, Miami, and Charlotte, American offers a wide range of travel options. Passengers can choose from Economy with affordable fares, Premium Economy with extra space, or Business and First Class featuring flat-bed seats, premium dining, and lounge access. With a modern fleet and membership in the oneworld alliance, American Airlines combines global reach with comfort and reliability.

TAP Air Portugal is the national flag carrier and the largest airline in Portugal, with its main hub at Humberto Delgado Airport in Lisbon. As a member of the Star Alliance, TAP operates an average of 2,500 flights per week to more than 90 destinations in over 30 countries. Many of its aircraft feature USB outlets for charging devices, while most long-haul flights include complimentary onboard entertainment with movies, TV shows, music, and games. For travelers looking for affordable options, TAP also offers low-cost fares on select routes, making it easy to find cheap flights with the airline.

Aer Lingus is Ireland's national airline, established in 1936. It operates over 100 routes, connecting Europe and North America from its main hub at Dublin Airport, as well as from Cork, Shannon, and Knock. A member of the International Airlines Group (IAG), Aer Lingus is recognized as a 4-star airline by Skytrax. The airline is known for its Irish hospitality and offers a range of services, including its AerClub loyalty program. Aer Lingus utilizes a modern fleet of Airbus aircraft, including the A321neoLR, for efficiency, comfort, and safety.