This thesis presents an approach for supporting the information access requirements of engineering designers. Technical and cultural factors are increasing the quantity of information that is available to designers. As a consequence, they require improved tools not just to retrieve this information but also to allow it to be organised and classified into meaningful structures to assist in its management. The research has been undertaken from two interrelated standpoints. The first focused on empirical studies of the information access requirements of practising designers. The second concerned the development, based on the key findings from the initial studies, of classification structures for aerospace design information and their incorporation in a computer-based information system. The empirical studies of designers were carried out in two separate stages. The first involved the characterisation of the information usage of a range of engineering designers with different backgrounds. The results indicated important differences in the usage and storage of information between designers. The second study examined documents used by practising designers. From this, a number of core classification scheme types were identified that allow information to be organised from a variety of user perspectives. The results of the empirical studies informed the development of a novel information system based on a combination of. (i) faceted-like, automatic, non-mutually exclusive classification principles and (ii) a hybrid browsing approach that `prunes' the browsable classification scheme, according to concept selections made by the user. The system overcomes some of the usual problems of browsing classification structures and allows the inference of linked relationships between different classification categories. This represents a powerful feature that is beyond the capabilities of existing search approaches. The benefits of the system, when applied to a number of typical engineering information search scenarios, are discussed followed by an evaluation of the approach. Finally, a number of conclusions and suggestions for future research are suggested.