SUPPLEMENT to the LONDON GAZETTE, 2 JANUARY, 19473912. Air Marshal Sir Arthur Coningham, K .C.B., D.S.O., M.C., D .F.C., A .F.C., was appointed Commander, Advanced Allied Expeditionary Air Force, and he undertook this responsibility on detachment from the Second Tactical Air Force. The Commander, Advanced A .E.A .F .was the one air commander with whom the Commander-in-Chief, 21st Army Group dealt in his capacity Com-as mander-in-Chief, Land Forces, during the initial phases of the operation. The Commander, Advanced A .E.A .F .had the necessary authority to implement the requests for air action made by the Army, referring to meany requests for air support beyond (the resources of the two tactical air forces. Headquarters, Advanced A .E.A .F. was setup at Uxbridge on 1st May, 1944. Its War Room, where meetings to coordinate operations of the tactical air forces were held daily, was adjacent to the Combined Operations Room and the Combined Control and Reconnaissance Centres referred to below. Machinery of Control of Tactical Air Forces 13. Throughout the preparatory and assault periods, the control of the fighter bombers and the light and medium bombers of the two tactical air forces was exercised through a Combined Operations Room located at Uxbridge. This Operations Room was staffed by representatives of the United States Ninth Air Force and the Royal Air Force Second Tactical Air Force. Also under the direction of the Commander,- Advanced A .E.A .F., a Combined Control Centre was setup and operated by the Air Officer Commanding No. 11 Group, Royal Air Force, with the full collaboration of the Commanding General, United States IXth Fighter Command and with authoritative representation of the United States Army VIHth Fighter Command. Tihis Combined Control Centre was manned by a British/ American staff and was, in effect, ithe Operations Room of No. 11 Group, Air Defence of Great Britain, with the complete static signals system of the old organisation overdeveloped along period and augmented by additional communication facilities. This Centre planned, co-ordinated and controlled all fighter operations in the initial phases of the operations it was also responsible for issuing executive instructions for the fighter bombers. 14. A Combined Reconnaissance Centre was also operated under the command of the Commander, Advanced A .E.A .F .to co-ordinate and direct 'the visual and photographic reconnaissance efforts of both the British and United States reconnaissance forces, during the initial phases. 15. At Appendix “B”*is a diagram, setting out the chain of control and the locations of various Headquarters at the time of the Assault. Modifications in this chain of control were made later as they became necessary. Headquarters, Royal Air Force Second Tactical Air Force and Headquarters, United States Ninth Air Force moved overseas on 4th August, 1944, and Headquarters, Advanced A .E.A .F. moved to the Continent on 9th August, 1944 to economise in communications, this Headquarters was located alongside Headquarters, United States Ninth Air Force. It continued in the Afield 2 *Appendices not reproduced. alongside this latter Headquarters (which was located next to 12th United States Army Group), in the advance from the Cotentin Peninsula to the Paris area, where it was located at Versailles. Main Headquarters, A .E.A .F. moved from Stanmore to the Continent on 8th September, 1944, and was located alongside your own Headquarters at Julouville. Communications at that place were quite inadequate to meet the needs of a headquarters of the size concerned, and Main Headquarters A .E.A .F .moved with Supreme Headquarters to Versailles on 19th September, 1944.16. Plans had been drawn up for the further move of Advanced Headquarters, A .E.A .F. with Advanced Headquarters Ninth Air Force to Verdun. In view of impending developments, chiefly the absorption of A .E.A .F S.H.into .A.E.F., these plans were not put into operation. Headquarters, Advanced A .E.A .F. was therefore merged into Headquarters Main A .E.A .F.at 1200 hours on 23rd September, 1944-Part II.— Pol icy and P l ann g.(a)in Operations prior to D-Day. Operation “Overlord ”.17. Operation “Overlord ”was part of a large strategic plan designed to bring about the defeat of Germany by heavy and concerted assaults on German-occupied Europe from the United Kingdom, the Mediterranean and Russia. A Joint Study and Outline Plan for Operation “Overlord ”was completed in July, 1943. This plan was elaborated in more detail under the title "Neptune "—Initial Joint Plan and Maintenance Project/Administrative Plan— by the Allied Naval Commander-in-Chief, the Commander-in-Chief, 21st Army Group and myself. Operation “Neptune ”provided for the launching of an assault from the United Kingdom across the English Channel, designed to secure a lodgment area on the Continent, from which wider offensive operations could be developed. 18. To cover the operations of all air forces allotted to Operation “Neptune ”,an Overall Air Plan was evolved, which outset briefly the Joint Plan, the command and control of air forces involved, the principal air tasks and their development through the preliminary and preparatory phases, the assault and follow-up, and air operations subsequent to the assault and securing of the lodgment area. The main features of the Overall Air Plan are more fully dealt within paragraphs 25 and 26 below. 19. To supplement the Initial Joint Plan for Operation “Neptune ”,joint instructions and memoranda were issued by the Commanders-in- Chief of the Naval, Army and Air Forces. Administrative and Signals Planning. 20. To supplement the Overall Air Plan, additional Operational and Administrative Instructions were prepared and issued. In particular, comprehensive Administrative plans were issued for the Royal Air Force formations in A .E.A .F. and the United States Ninth Air Force. These Administrative plans, which were issued separately, were based on three previously agreed fundamental decisions: The—(a) relative administrative responsibilities of the Army and Air Forces in the field. The division laid down was closely followed and, in practice, worked excellently.