Development works and modification
21.—(1)  A certified operator of an aerodrome must not carry out any work that results in changes to the physical characteristics of any runway, taxiway, aircraft stand, final approach and take‑off area, touchdown and lift‑off area, helicopter ground taxiway or helicopter stand at the aerodrome, except in accordance with paragraph (2).
(2)  A certified operator of an aerodrome must —
(a)before carrying out the work, notify the Director‑General of Civil Aviation of —
(i)the nature and purpose of the changes mentioned in paragraph (1); and
(ii)the plans relating to the work mentioned in paragraph (1), including a description of the proposed design and work schedule;
(b)before carrying out the work, conduct a risk assessment in accordance with the certified operator’s safety management system;
(c)ensure that consideration is given to the safety of aircraft operations at the aerodrome;
(d)while carrying out any work described in paragraph (1), ensure that safety measures, which take into account the risk assessment conducted under sub‑paragraph (b), are imposed; and
(e)keep, for the period specified in the Third Schedule, a record of the risk assessment conducted under sub‑paragraph (b).
(3)  Where any work mentioned in paragraph (1) is carried out, the certified operator of the aerodrome must obtain the approval of the Director‑General of Civil Aviation before operating the runway, taxiway, aircraft stand, final approach and take‑off area, touchdown and lift‑off area, helicopter ground taxiway or helicopter stand, as the case may be.