36. For article 123 (height keeping performance - aircraft registered elsewhere than in the United Kingdom) substitute—
123.—(1) An aircraft registered elsewhere than in the United Kingdom must not fly in Reduced Vertical Separation Minimum airspace in the United Kingdom unless—
(a)it complies with paragraph (2) or (3); or
(b)it is otherwise authorised by the appropriate air traffic control unit.
(2) An aircraft complies with this paragraph if it is registered in an EASA Member, other than the United Kingdom, and it is flying under and in accordance with an approval issued by the competent authority of an EASA Member under Subpart D of Part-SPA.
(3) An aircraft complies with this paragraph if it is registered elsewhere than in an EASA Member and—
(a)it is so equipped with height keeping systems as to comply with the law of the country in which the aircraft is registered in so far as that law requires it to be so equipped when flying in any designated airspace; and
(b)the equipment is capable of being operated so as to enable the aircraft to maintain the height keeping performance notified for the airspace in which the aircraft is flying, and it is so operated.”.