Air transport did not go unscathed through the 4th industrial revolution. This phenomenon has also been felt in the intensification of air traffic, especially if we think about the time it saves us. As a result, new business practices have emerged with a particular aim at boosting the air transport sector, making it accessible to all or almost everyone. The importance of this means of transport was evident, however, it potentiated the appearance of several problems related to the passengers protection and the diversity of occurrences. In this context was created the Regulation (EC) No. 261/2004 of the European Parliament and of the Council of 11 February 2004 establishing common rules on compensation and assistance to passengers in the event of denied boarding and cancelled or long delay flights. The main concern is the injured passenger, in relation to the provision of the service supplied by the airlines, which must be compensated as a matter of urgency. While laying down harmonised rules on compensation and assistance to passengers on the grounds of denied boarding, cancellation or delay of flights, it also provides the possibility for the operating air carrier to escape its responsibilities. The appeal to the undeterminate concept of "extraordinary circumstances" is undoubtedly a hallmark of the airlines. The Court of Justice (of the European Community and currently of the European Union) has a decisive role in the understanding of the concept of "specific circumstances". It can also be seen that the diversity of the issues requires clarification on the situations in which passengers can assert their rights. We will focus our approach on liability for company non-compliance. We will conclude with a critical analysis of the impasse over the amendment of the Regulation in question. Twenty years after its term, and despite the fact that the dynamics of air transport have changed substantially, the passengers protection remains, allowing constant violations of their rights.

Key words: cancellation, delay, liability, flight.