Air Power Versus U-Boats: Confronting Hitler's Submarine Menace

Air Power Versus U-Boats: Confronting Hitler's Submarine Menace Released through The Black Vault, a digital archive of declassified documents, this study examines the European-theater air campaign against German U-boats in the Battle of the Atlantic. The U.S. Army Air Forces in World War II Air Power versus U-boats Confronting Hitler’ s Submarine Menace in the European Theater A. Timothy Warnock AIR FORCE HISTOR Y AND MUSEUMS PROGRAM 1999 Air Power versus U-boats Confronting Hitler’ s Submarine Menace in the European Theater More than fifty years after World War II, America’ s major air power contribution to the war in Europe—in efforts such as Big Week, Re- gensburg, and Patton’ s dash across Europe—live on in the memories of airmen and students of air power. Never before had air forces per- formed so many roles in so many different types of operations. Air power proved to be extremely flexible: wartime missions included maintaining air superiority, controlling the air space over the battle- field; strategic bombardment, destroying the enemy’ s industrial and logistical network; air-ground support, attacking targets on the battle- field; and military airlift, delivering war matériel to distant bases. Perhaps one of the least known but significant roles of the Army Air Forces (AAF) was in antisubmarine warfare, particularly in the European-African-Middle Eastern theater. From the coasts of Greenland, Europe, and Africa to the mid-Atlantic, AAF aircraft hunted German U-boats that sank thousands of British and American transport ships early in the war. These missions supplemented the efforts of the Royal Navy, the Royal Air Force Coastal Command, and the U.S. Navy, and helped those sea forces to wrest control of the sea lanes from German submarines. German U-boats Threaten Allied Shipping: December 1941–June 1942 Before the United States entered World War II, the German submarine offensive against shipping across the North Atlantic was throttling Great Britain. U-boats were sinking merchant ships and tankers delivering war matériel from the United States faster than the British could replace them. The concern for both nations was that German submarines might counterbalance the advantage in resources that the United States provided to Great Britain under the Lend-Lease Act. In the long term, German control of the sea lanes might pose an even greater threat. Early in 1941, British and American leaders held secret meetings in Washington, D.C., to consider the possibility of becoming allies in a war against the European Axis (Germany and Italy) and Japan. The officials realized that an Allied war in Europe would eventually entail an invasion of Europe across the English Channel. Without American and British control of the shipping lanes, that invasion would be impossible. Meanwhile, enemy submarine forces concentrated on a single strategic objective: to sink enough Allied shipping to cripple the war effort. At the beginning of the war, Germany withdrew its U-boats from operational areas when Allied antisubmarine warfare severely limited their operations against shipping. But German dictator Adolf Hitler saw the Atlantic Ocean as his first line of defense in the west. Nazi U-boats could prevent the Allies from striking back with air and sea power, and from transporting troops and supplies to be used in any land invasion of Europe. The United States was grossly unprepared for an antisubmarine war. The U.S. Navy, under the command of Adm. Ernest J. King, was responsible for antisubmarine defenses, but it lacked trained manpower, specialized surface vessels, and long-range or very-long-range aircraft. Thus, King had to call for support from the U.S. Army Air Forces (AAF) commander, Gen. Henry H. Arnold. But, like the Navy, the AAF was unprepared for antisubmarine operations. Adm. Ernest J. King PHOTO # 1 AAF aircraft carried bombs rather than depth charges and lacked radar or other special submarine detection equipment. No trained personnel were available for the specialized job of detecting and attacking submarines from the air, and the AAF had no organization dedicated to antisubmarine operations. Perhaps the most serious problem was that the few combat aircraft on hand (approximately 3,000) were in sudden demand for many other important operations. Germany quickly took advantage of this unpreparedness. Within a month of the U.S. declaration of war, the first German submarine arrived in American waters. Between mid-January 1942 and the end of June, U-boats sank 397 ships—171 off the east coast of the United States, 62 in the Gulf of Mexico, and 141 in the Caribbean Sea. Many of these vessels were tankers. The AAF Response: Tactics, Technology, and Organization Reacting to the ferocity of the U-boat offensive, the AAF developed and adopted tactics that exploited the submarine's need to surface frequently. A submarine emerged daily, usually at night, to recharge its batteries, ventilate the boat, and permit crew members to come topside. It often traveled or pursued convoys on the surface because its submerged speed averaged three knots, whereas its surface speed was about fifteen knots, much faster than the ten knots of most merchant ships. Furthermore, submarines remained on the surface to maneuver for attacks and usually to fire their torpedoes or guns before submerging. When Allied escort ships discontinued their search for the submerged U-boats, the Germans could emerge again and circle ahead of the convoy to make another attack. Aerial patrols prevented this maneuver by forcing submarines to dive frequently and remain submerged too long to catch up with the convoys. By June 1942, the AAF was conducting two broad types of antisubmarine patrols. At the request of the U.S. Navy, AAF crews often escorted Allied convoys to prevent enemy submarines from attacking ships at close