S T A T U T O R Y I N S T R U M E N T S 2021 No. 549  CIVIL AVIATION  The Air Navigation (Restriction of Flying) (Duxford)  Regulations 2021  Made - - - - 5th May 2021  Coming into force - - 23rd July 2021  The Secretary of State has decided that it is in the public interest to restrict flying in the vicinity of  Duxford Aerodrome, Cambridgeshire, by reason of the holding of flying displays.  The Secretary of State makes the following Regulations in exercise of the powers conferred by  article 239 of the Air Navigation Order 2016( a ).  1.  These Regulations may be cited as the Air Navigation (Restriction of Flying) (Duxford)  Regulations 2021 and come into force on 23rd July 2021.  2.  In regulation 3(2) the times referred to are Co-ordinated Universal Time( b ).  Citation and commencement  Interpretation  Restricted airspace  3. —(1) Subject to paragraph (3), and during the periods specified in paragraph (2), no aircraft is  to fly below 4,500 feet above mean sea level within the area bounded by a circle having a radius  of 2.2 nautical miles whose centre is at 520539N 0000753E.  (a) between 0800 hours and 1700 hours on 23rd July 2021,  (b) between 1100 hours and 1700 hours on 24th and 25th July 2021,  (c) between 0800 hours and 1700 hours on 17th September 2021, and  (d) between 1100 hours and 1700 hours on 18th and 19th September 2021.  (3) Paragraph (1) does not apply to any aircraft flying in accordance with a permission issued by  the Duxford Aerodrome flying display director.  (2) The periods referred to in paragraph (1) are—  ( a ) S.I. 2016/765, to which there are amendments not relevant to these Regulations.  ( b ) Co-ordinated Universal Time (UTC) is one hour behind British Summer Time (BST). 