The Atlantic represented for long-distance passenger transportation modes an important challenge to test technologies due to the long distances involved and the limited intermediary locations where a technical stop could be made. Both sides of the North Atlantic have substantial levels of economic activity, implying that a mode able to cross the North Atlantic non-stop safely would be a commercial success. The steamship was the first powered mode to set regular passenger services from the late 1830s, initially taking more than 10 days, but technical improvements reduced the transit time to about 6 days by the 1870s. By the time transatlantic liner services started to be abandoned in the 1950s, transit times were reduced to 4 days.
Dirigibles were seriously considered in the 1930s, with the setting of the first transatlantic air passenger flights. Their slow speeds and the Hindenburg destruction during a landing accident in 1937 marked the end of dirigibles as passenger transportation modes. Both propeller and seaplane (“flying boat”) transatlantic services began in the mid-1930s. The seaplane initially got an advantage with its capacity to land on water. Still, this advantage impeded as technical improvements were made to propeller planes, which left the seaplane with limited range. It was later abandoned as a long-distance transport mode. The introduction of pressurized propeller planes (e.g. Constellation) in 1945 permitted the first regular transatlantic services with two technical stops, Gander (Newfoundland) and Shannon (Ireland), and a flight time of about 11 hours.
The introduction of passenger jet planes (e.g. Boeing 707) in transatlantic services in 1958 marked the downfall of long-distance propeller plane services. The flying time was reduced to 8 hours with one technical stop in Gander, Newfoundland. Technical improvements in the 1960s removed the necessity of technical stops and enabled for the first time direct long-distance transatlantic services. Fast transatlantic supersonic services were introduced in 1976 and remained operational for a quarter of a century. However, high cost and high energy consumption made supersonic services commercially nonviable, and the technology was retired in 2003. Therefore, for more than half a century, transatlantic flight times have remained relatively constant.