Air traffic volume continues to grow steadily. In the era of globalization, it is quite simply the transportation of choice. However, current airport infrastructure is not sufficient to cope with this growth. Most major German and European airports are already approaching maximum capacity. Above all, it is the capacity of airport runways and the necessary take-off and landing slots which are proving the main bottleneck for airlines. In addition to factors such as safety and service, competition in the aviation industry is being primarily determined by the allocation of economically attractive slots at peaktimes. Only those airlines with such lucrative slots, or which can afford to acquire them, have a chance of competing in the air transportation business. This dissertation aims to present, analyze and assess the current slot allocation system and the legal evaluation of those possibilities currently being discussed regarding more efficient use of take-off and landing rights at busy airports. In addition to questions arising from the proposed slot trading system, the main subject of this dissertation is the question concerning the legal nature of slots, as well as any rights which airlines, airport operators and the public sector may have. In particular, the dissertation focuses on property rights and the right to equal opportunity and non-discriminatory participation, also in respect of grandfather rights granted to airlines (also regarding an incremental percentage slot withdrawal) and achieving the right balance between established providers and new applicants. The dissertation does not present nor develop new, more efficient allocation mechanisms, but examines to what extent the mechanisms currently practised and those changes targeted by the European Commission are consistent with applicable law. Die Vergabe wirtschaftlich interessanter Slots zu den Hauptverkehrszeiten bestimmt neben Faktoren wie Sicherheit und Service den Wettbewerb im Luftverkehr. Ziel der Arbeit ist eine Darstellung, Analyse und Beurteilung des gegenwärtig praktizierten Systems der Slotvergabe sowie eine rechtliche Beurteilung der in der Diskussion stehenden Möglichkeiten zur effizienteren Nutzung der Slots. Die Frage nach der Rechtsnatur eines Slots und nach möglichen Ansprüchen der Fluggesellschaften, der Flughafenbetreiber und der öffentlichen Hand bilden neben weiteren Fragen, die sich aus dem angestrebten Handel mit Slots ergeben, den Kern der Untersuchung. Die Autorin widmet sich insbesondere dem Eigentumsrecht und dem Recht auf chancengleiche und diskriminierungsfreie Teilhabe, insbesondere auch in Bezug auf die den Fluggesellschaften eingeräumten Großvaterrechte und einen sachgerechten Ausgleich zwischen alteingesessenen Anbietern und Neubewerbern.