Following the 1978 deregulation, U.S. carriers did not manage to make an aggregate profit for 12 years in 31, including four years where combined losses amounted to $10 billion, but rebounded with eight consecutive years of profits since 2010, including its four with over $10 billion profits. They drop loss-making routes, avoid fare wars and market share battles, limit capacity growth, add hub feed with regional jets to increase their profitability. They change schedules to create more connections, buy used aircraft, reduce international frequencies and leverage partnerships to optimise capacities and benefit from overseas connectivity.
Codesharing is the most common type of airline partnership; it involves one airline selling tickets for another airline's flights under its own airline code. An early example of this was Japan Airlines' (JAL) codesharing partnership with Aeroflot in the 1960s on Tokyo–Moscow flights; Aeroflot operated the flights using Aeroflot aircraft, but JAL sold tickets for the flights as if they were JAL flights. This practice allows airlines to expand their operations, at least on paper, into parts of the world where they cannot afford to establish bases or purchase aircraft. Another example was the Austrian–Sabena partnership on the Vienna–Brussels–New York/JFK route during the late '60s, using a Sabena Boeing 707 with Austrian livery.
Although Germany lacked colonies, it also began expanding its services globally. In 1931, the airship Graf Zeppelin began offering regular scheduled passenger service between Germany and South America, usually every two weeks, which continued until 1937. In 1936, the airship Hindenburg entered passenger service and successfully crossed the Atlantic 36 times before crashing at Lakehurst, New Jersey, on May 6, 1937. In 1938, a weekly air service from Berlin to Kabul, Afghanistan, started operating.