Holds are a standard procedure for managing traffic flow into an airport and maintaining safe separation between aircraft. These racetrack-shaped flight patterns allow aircraft to be held at different altitudes while the pilot awaits further instructions from air traffic control (ATC).

Scotland’s lower airspace is based on a design built for aircraft and navigation technology that belong to another era. Demand has grown, aircraft have changed and the invisible infrastructure that keeps flights safely moving needs a comprehensive upgrade to keep pace.