91.—(1) A person shall not act as an air traffic controller or hold himself out, whether by use of a radio call sign or in any other way, as a person who may so act unless he is the holder of, and complies with the privileges and conditions of—
(a)a valid student air traffic controller’s licence granted under this Order and he is supervised in accordance with article 92(10);
(b)an appropriate valid air traffic controller’s licence granted under this Order; or
(c)a valid air traffic controller’s licence so granted which is not appropriate but he is supervised as though he was the holder of a student air traffic controller’s licence.
(2) A person shall not act as an air traffic controller unless he has identified himself in such a manner as may be notified.
(3) A licence is not required by any person who, acting in the course of his employment, passes on such instructions or advice as he has been instructed so to do by the holder of an air traffic controller’s licence entitling the holder to give such instructions or advice.
(4) Nothing in this article prohibits the holder of a valid air traffic controller’s licence from providing at any place, or for any sector for which the licence includes a valid certificate of competence, information to aircraft in flight in the interests of safety.
(5) A licence is not required by any person who acts in the course of his duty as a member of any of Her Majesty’s naval, military or air forces or as a member of a visiting force.