120 Squadron's strength doubled. This still only put all of thirty-eight VLRs over the Mid-Atlantic Gap. The arrival of 25th Antisubmarine Wing, USAAF, with its medium-range B-24s (equipped with H2S, probably built by Canadians), made it possible to free up Coastal Command VLRs without it. The growth in numbers of escort carriers meant "a dramatic increase of USAAF Fortresses and medium-range Liberators" could be based in Newfoundland. 25h Wing flew over the Bay of Biscay, where they sank one U-boat before being redeployed to Morocco. Increasing availability of escort carriers reduced the hazard of the Gap. After a crisis in March which nearly had Churchill and the Admiralty abandon convoys altogether, the Mid-Atlantic Gap was finally closed in May 1943, when RCAF VLRs became operational in Newfoundland, by which time the Battle of the Atlantic was largely won. See also Mid-Ocean Escort Force Mid-Ocean Meeting Point GIUK gap CAM ship MAC ship Project Habakkuk Notes References Bowen, E. G. Radar Days. Philadelphia: Institute of Physics Publishers, 1998. (Reprints A. Hilger 1987 edition). Costello, John, and Hughes, Terry. The Battle of the Atlantic. London: Collins, 1977. . Deighton, Len. Bomber. St Albans: Triad, 1978. Gordon, Don E. Electronic warfare: Element of Strategy and Multiplier of Combat Power. New York: Pergamon Press, 1981. Harris, Arthur T., Marshal of the Royal Air Force. Bomber Offensive. Toronto: Stoddart, 1990 (reprints 1947 Collins edition). Hartcup, Guy. The Challenge of War: Britain's scientific and engineering contributions to World War Two. New York: Taplinger Publishing Co., 1970. Ireland, Bernard. The Battle of the Atlantic. Annapolis, MD: United States Naval Institute Press, 2003. Jones, R. V., Professor. Most Secret War: British Scientific Intelligence 1939–1945. London: Coronet Books, 1979 (reprints 1978 Hamish Hamilton edition). Longmate, Norman. The Bombers: The RAF offensive against Germany 1939–1945. London: Hutchinson, 1983. . Lyall, Gavin. The War in the Air: The Royal Air Force in World War II. New York: Morrow, 1968. Middlebrook, Martin. Convoy. New York: William Morrow & Co., 1976. Milner, Marc. North Atlantic run: the Royal Canadian Navy and the battle for the convoys. Annapolis, MD: United States Naval Institute Press, 1985. Milner, Marc. Battle of the Atlantic. St. Catherines, ON: Vanwell Publishing, 2003. Price, Alfred, Dr. Aircraft versus submarine: the evolution of the anti-submarine aircraft, 1912 to 1972. London, Kimber, 1973. Saward, Dudley. "Bomber" Harris: The Story of Marshal of the Royal Air Force, Sir Arthur Harris, Bt, GCG, OBE,