The employment contracts of aircrew have special features that affect the application of the rules of private international law (PIL): the problems in identifying the habitual State of work; the impact of aviation law; and the difficulties in classifying the employment relationship. These specialities require a specific study of PIL which is also justified by the topicality of the subject, given the transformation of labour relations in the aviation sector during the last years and the number of disputes that have taken place in the different Member States.

The problems in identifying the habitual place of work are not only due to the intrinsic characteristics of the work, i.e. its mobile and extraterritorial nature, but also to the relocation of workers by the employing airlines. The connecting factor and the forum of the habitual place of work are assimilated in Rome I and Brussels I bis Regulations to the place from which workers provide services. Problems arise because the interpretation given to the concept of “habitual place of work” may lead to States that do not meet the requirements of proximity, foreseeability and protection that should characterise connecting factors and forums.

In addition, the employment contract regime of aircrews is characterised by its fragmentation: the contract is partly affected by aviation law rules, while the labour rules determined by Art. 8 of Rome I Regulation apply for the rest. The concept of "operating base" becomes relevant in the application of PIL rules. Although a direct assimilation with the habitual place of work is excluded, it is necessary to analyse the real relevance that the assigned operating base may have in determining the applicable law and the international jurisdiction, taking into account that it also determines the application of collective agreements and the State of affiliation to social security.

Difficulties in contract classification are due to the spread of atypical employment modalities and the existence of different forms of cooperation between airlines. The use of atypical working arrangements is a trend characteristic of low-cost airlines, which use them in order to reduce social and labour costs. These include bogus self-employment of pilots, work of unpaid pilots, on-demand contracts and recruitment through intermediary companies. These contracts raise specific classification issues. The application of the protective labour connecting factors and forums of Rome I and Brussels I bis Regulations is only possible if the relationship between the airline and the pilot/flight assistant is qualified as an employment relationship in accordance with the autonomous European concept of “employment contract”. For that reason, it is necessary to assess the compatibility of each of the modalities with the defining features of the concept. In addition, cooperation among airlines makes it difficult to identify the employer or employers, i.e. whose relationship with the employee is regulated by the law of the employment contract, and the worker can sue by invoking the labour forums.

This doctoral thesis focuses on the abovementioned specialties in order to describe, first of all, the context of labour relations in the aviation sector. Secondly, the scope of application of the employment contract law is delimited, focusing the analysis on the most controversial issues and the usual casuistry. Subsequently, a parallel study is made of the determination of the applicable law and the international jurisdiction, justified mainly by the fact that the concepts of “habitual place of work” and “engaging establishment” are shared in both sectors. The analysis is based on a distinction between connecting factors and forums determined by the performance of the work (habitual place of work) and based on circumstances outside the performance (those based on the figure of the employer and on the autonomy of the will), combined with a transversal treatment of the connection of the closest links.