Article 21 1.

Pilots shall be required to hold a pilot licence and a pilot medical certificate appropriate to the operation to be performed, except for situations in which, as a result of the adoption of implementing acts referred to in point (c)(i) of Article 23(1), taking into account the objectives and principles set out in Articles 1 and 4, and in particular the nature and risk of the activity concerned, such licences or medical certificates are not required.