C45c 1st Training Flight in a Hawker Signed Thornton and Simpson (A)

28 April 77 Introduction of the Hawk into the Royal Air Force Special Postmark Commemorating the First Training Flight in a Hawker Siddeley Hawk at RAF Valley. Flown in H S Hawk XX167. Personally Signed by Duncan Simpson Hawker Siddeleys Chief Test Pilot who has been closely associated with test flying of the Harrier and Hawk & Gp Capt D L F Thornton OBE Officer Commanding RAF Valley Details enclosed.