Boston, MA BOS to Madrid MAD flight with United

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.

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.

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.

Lufthansa is Germany’s largest airline and one of the leading carriers in Europe, connecting travelers to destinations worldwide from its main hubs in Frankfurt and Munich. Its modern fleet offers a wide choice of travel experiences, from Economy Class with affordable fares and onboard entertainment to Premium Economy, Business Class, and First Class with extra comfort, fine dining, and exclusive lounge access.

Air France is the national flag carrier of France and one of Europe’s leading airlines, connecting travelers to destinations across Europe, the Americas, Asia, Africa, and the Middle East. Operating from its main hub at Paris Charles de Gaulle Airport, Air France offers a modern fleet with services ranging from affordable Economy fares to Premium Economy and Business Class featuring spacious seating, fine dining, and lounge access. Known for its French hospitality and style, Air France combines comfort, service, and global connectivity for both business and leisure travelers.

Turkish Airlines is the national flag carrier of Turkey and one of the world’s leading airlines, flying to more international destinations than any other airline. Based in Istanbul, it connects travelers to Europe, Asia, the Americas, Africa, and beyond. Passengers can choose from Economy Class with comfortable seating, WiFi, and in-flight entertainment, or upgrade to Business Class for spacious seating, gourmet dining, and lounge access. With its award-winning service and global reach, Turkish Airlines is a top choice for both business and leisure travel.

Iberia is the national airline of Spain and a key member of the International Airlines Group (IAG), operating flights throughout Europe and to major global destinations. Its wide range of services makes travel easy and flexible—Economy passengers enjoy affordable fares with comfort, while Business Class travelers can experience premium seating, exclusive lounges, and enhanced dining. From short domestic flights to intercontinental journeys, Iberia combines Spanish hospitality with modern amenities, making it a popular choice worldwide.

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.