This study investigated new methods for allocating airport slots. The currently used and proposed systems have been reviewed and their advantages and disadvantages highlighted. A survey of airlines operating from Heathrow was conducted to establish which attributes airlines operating from a congested airport want the new system to contain and to identify which systems do they consider as most efficient. In addition, two interviews were conducted with managers from BAA in order to acquire an insight into the company’s opinion on the issue. The slot ownership dilemma was addressed since slot ownership will influence the selection and effectiveness of the new slot allocation system. The findings from the research suggest that the non-residential airlines at Heathrow airport are satisfied with the currently used system for slot allocation and that they are also in favour of a system that will be based on overall performance. The final chapter contains recommendations for an option to be used for slot allocation involving a combination of slot auctions and slot-leasing, and involves the leasing of the available slots in auctions that will be carried out by an independent body.