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UK Civil Aviation Regulations

These are published by the CAA on our UK Regulations pages. EU Regulations and EASA Access Guides published by EASA no longer apply in the UK. Our website and publications are being reviewed to update all references. Any references to EU law and EASA Access guides should be disregarded and where applicable the equivalent UK versions referred to instead.

The nominal Vertical Separation Minima (VSM) concept exploits known 'allowances' within the 1,000 ft vertical separation minima that was defined by ICAO in 1958 which was designed to take into account known inaccuracies in altimeters, aircraft level keeping etc. The advent of more modern and accurate systems onboard aircraft means that we are able to accept minor altimeter setting variances between flights for short periods of time, in order to reduce workload for pilots and controllers. The nominal VSM Safety Report details a conceptual safety argument for the use of a nominal VSM and presents an overview of progress, consolidates all evidences gained, and outstanding issues related to the delivery of nominal VSM.
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