ABSTRACT
Even though ATC practice involves applying just three standards or rules of separation (vertical, lateral and longitudinal), the work is complex because of a range of other factors. For example, the weather influences the traffic flow. Aircraft may be required to divert from an original flight plan due to poor weather or, in a desire to get above or below poor weather conditions, aircraft may request flight level changes. Cross-winds or tail winds may alter an aircraft's performance, resulting in the aircraft not performing as anticipated. Other environmental conditions (e.g. bushfires and fog) can also alter the flight plan.
