Unless otherwise prescribed by the appropriate ATS authority, a flight plan for a flight to be provided with air
traffic control service or air traffic advisory service shall be submitted at least sixty minutes before departure, or, if submitted
during flight, at a time which will ensure its receipt by the appropriate air traffic services unit at least ten minutes before the aircraft is estimated to reach: a) the intended point of entry into a control area or advisory area; or b) the point of crossing an airway or advisory route.
