9 Where the Regional Director General has approved the use of an airport for the landing, by any Canadian air carrier licensed under Part II of the Canada Transportation Act, of an aircraft on a flight conducted exclusively for the purpose of improving the skill and knowledge of the aircrew personnel of that air carrier and, where arrangements are made in advance with the officer in charge of the airport where the landing takes place, the landing charge for each such landing is 20 per cent of the applicable charge prescribed in section 4.
[...]