Except in the cases of provisional suspensions or variations pending further enquiry, decisions made at the direction of the Secretary of State, and medical certificates, a decision to revoke, suspend or refuse to grant a certificate, licence etc. can be appealed against to the Members of the CAA (Civil Aviation Regulations 1991 - Regulation 6).
Full details of the appeals process can be obtained from:
Secretary and Legal Adviser
Civil Aviation Authority
Westferry Circus, Canary Wharf, London, E14 4HE
Further information is available for requests for review of certain personnel licensing and certification decisions.