4.—(1) Subject to sub-paragraph (2), the holder of a licence that includes ratings of two or more of the classes specified in paragraph 5 must not at any one time perform the functions specified in respect of more than one of those ratings.
(2) The functions of the following ratings may be exercised at the same time—
(a)an Aerodrome Control Instrument Rating and an Approach Control Procedural Rating; and
(b)an Aerodrome Control Instrument Rating and an Approach Control Surveillance Rating, provided that the holder does not exercise the functions of any rating endorsement described in paragraph 2(a) to (c) of article 7 of the air traffic controllers’ directive included in the Approach Control Surveillance Rating.
(3) When a surveillance radar approach terminating at a point less than 2 nautical miles from the point of intersection of the glide path with the runway is being provided under an approach control surveillance rating, no other function under the approach control surveillance rating may be exercised at the same time.