Planning Listed Buildings & Conservation Act 1990, states the following: 'The Secretary of State may from time to time determine that any part of a local planning authority's area, which is not for the time being designated as a Conservation Area of Special Architectural or Historic Interest, the Character or Appearance of which it is Desirable to Preserve or Enhance, and if he so determines, he may designate that part as a Conservation Area'. 'I have asked the Secretary of State to Designate the Active Aerodrome (the unpettioned part) at Panshanger; also now modernly known as Panshanger Aerodrome as a Conservation Area'.