[en] The European Directive 96/12 requires that aircrew be considered as occupationally exposed persons and that measures are taken to determine the individual doses of air crew and cabin personnel. Consequently, several European research institutes have undertaken an extensive programme of air borne and mountain based experiments to measure the radiation field in the earth's atmosphere. Furthermore, Monte Carlo radiation transport calculations were done to follow the radiation cascades from the top of the atmosphere down to the earth's surface. Though the basic physical processes and radiation components have been studied previously, the determination of dose quantities require more physical information: Both operational (ambient dose equivalent) and risk related quantities (effective dose) contain non-physical information which is described by quality and radiation weighting factors, respectively. The radiation transport calculations show that at normal flight altitudes the spectral shapes of the particle fluences are essentially invariable. This permits to use calculated conversion coefficients to determine the dose quantities from calculated and experimental spectral data. This appears necessary especially for those radiation components whose dose contribution can not experimentally separated, but may considerably contribute to the effective dose considering the radiation factors presently recommended by the ICRP, e.g. for protons. The European Computer Package EPCARD for the Calculation of Aviation Route Doses was designed to combine the experimental and theoretical data in the best available way. The concept is to treat each major component of the cosmic rays separately, i.e. muons, electrons and photons, neutrons, protons and charged particles. The influence of geomagnetic shielding is considered based on calculations and experimental data, and the magnitude of solar modulation is inferred from neutron monitor data. Route doses are calculated along any specified aviation route and profile by integration along great circles. The essential characteristics of the programme are elucidated. Dose rate data are presented as obtained from measurements and calculations. (author)