The airlines’ responsibilities towards passengers and their luggage is one of the cornerstone elements of today’s commercial aviation, due to the specific nature of this means of transport. International private air law, as a subgroup of private law, is governed by acts that directly determine the relations and responsibilities between airlines and passengers, as well as ways of exempting the carrier from liability. Legislative acts in force on a worldwide basis, like the Montreal Convention, are adopted by countries that, in this way, commit their airlines. By observing the development of private air law and the difficulties faced by the idea of uniform definition of responsibility due to rapid development of air traffic through the last century, the extent to which that responsibility was successfully defined will be shown. This can be done by analysing the development and amendments of legislative acts, as well as examples that show occassionally irreconcilable differences in interpretation of events and the airlines’ liability by multiple courts, even within the same country. Although the legislation does exist, it faces problems in translation and even linguistic definitions of certain phrases, which sometimes can make the crucial difference between confirming the airline’s responsibility and exempting it.