163.—(1) In this article, a specified licence means—
(a)a National Private Pilot's Licence or United Kingdom Private Pilot's Licence; or
(b)a United Kingdom Commercial Pilot's Licence (Balloons) that is restricted to commercial operation and to the privileges of a United Kingdom Private Pilot's Licence (Balloons and Airships).
(2) Subject to paragraph (7), the holder of a specified licence, or of a licence which includes the privileges of a specified licence, may exercise any of the privileges of the specified licence if the holder has—
(a)a valid medical certificate issued under article 161;
(b)a medical certificate granted under Section 2 of Subpart A of Part-MED, including one which is valid for a Light Aircraft Pilot Licence issued under Part-FCL; or
(c)made a medical declaration in accordance with paragraph (3) which has not ceased to be valid in accordance with paragraph (4) and the holder complies with the conditions in paragraph (5).
(3) The holder of a licence makes a medical declaration in accordance with this article if they—
(a)reasonably believe that they—
(i)meet the medical requirements for a Group 1 Licence issued by the Driver and Vehicle Licensing Agency; and
(ii)are not subject to a disqualifying medical condition.
(b)make a declaration to that effect to the CAA in such form and in such manner as may be required or specified by the CAA; and
(c)in the case of a licence holder aged 70 years or more, have made such a declaration within the previous three years.
(4) A declaration made in accordance with paragraph (3)—
(a)ceases to be valid if it is withdrawn;
(b)must be withdrawn by the holder if they no longer reasonably believe that they satisfy the requirements of paragraph (3);
(c)may be withdrawn by the CAA if it has reason to believe that the holder—
(i)no longer meets the medical requirements in paragraph (3)(a)(i); or
(ii)is subject to a disqualifying medical condition.
(5) The holder of a licence who does not have a medical certificate and relies on satisfying the requirements of paragraph (3) may only exercise the privileges of the licence—
(a)in an aircraft with a maximum take-off mass of 5,700kg or less;
(b)with not more than three passengers on board;
(c)by day or when exercising the privileges of a night rating;
(d)in visual meteorological conditions or when exercising the privileges of an instrument meteorological conditions rating; and
(e)within the United Kingdom unless the holder has the permission of the competent authority for the airspace in which the aircraft is being flown.
(6) For the purposes of this article, “disqualifying medical condition” means any physical or mental condition or illness, or any history of such a condition or illness, including—
(a)any alcohol or drug abuse, addiction or misuse;
(b)any neurological condition;
(c)any functional disability;
(d)any surgery or medical treatment;
(e)any collapse, fainting or loss of consciousness;
(f)any history of (a) to (e); or
(g)such other medical conditions as the CAA may specify,
that might impair the safe operation of normal flight controls or render the licence holder unfit at any time to perform any function for which the licence is granted.
(7) The holder of a specified licence wishing to exercise night rating privileges must additionally meet the colour vision requirements of MED.B.075 of Part-MED in order to be so entitled.