3.2 Flights departing from non-controlled aerodromes and intending to enter controlled airspace are required to file a flight plan with the nearest
ATC unit prior to departure. However, where an uncontrolled aerodrome is located outside a control zone and where telephone facilities are not available, flight plans may be filed during flight. In those cases pilots should ensure that the flight plan is filed at least ten minutes before entry into controlled airspace and that
RTF transmissions are kept to a minimum.