Most infringements occur in southern England where the skies are more crowded than in other areas of the country and where there is a complex airspace structure.

There is a concentration of infringements in the airspace surrounding Heathrow, Luton, Stansted, Southampton, Gatwick and London City airports.

Each of these incidents has a serious impact on airport operations, disrupting arrival and departure procedures, delaying passengers and increasing the workload of controllers and pilots as they take action to ensure the safety of all affected aircraft.