Not so, North Weald is Air Ground only and he presented an Air Ground Operators Certificate of Competence when he started.
Don't ask me where it came from....
Anyone can have an A/G certificate known as a Radio Operators Certificate of Competence (ROCC). Civil and military ATCOs and FISOs with a CURRENT unit endorsement or validation can simply apply to the CAA on the requisite form paying them £35 for the issue of the certificate. All others ie controllers/FISOs without a current qualification and civil and military pilots must pass a simple 2 part exam invigilated by an authorised examiner (like me!)