To be effective, the U-Boat hunt involved close cooperation among the operational forces of the Army Air Forces and the Navy. Unfortunately, this cooperative attitude did not lessen inter-service rivalries concerning organization, control, and the use of land-based aircraft. The Army Air Forces deemed the Navy's operational control practices involving its aircraft an intolerable situation, using most of AAFAC's specially trained aircraft and crews on endless preventive patrols off the East Coast looking at long stretches of water where submarines no longer ventured.
On 9 July 1943, as a result of a compromise proposal formulated in June by Arnold, Lt. Gen. Joseph T. McNarney, and Rear Adm. John S. McCain, Sr., the Army Air Forces and the U.S. Navy agreed that AAFAC would gradually withdraw from anti-submarine operations. In accordance with this agreement, the AAF by 6 October turned over 77 B-24 Liberators configured with antisubmarine equipment to the U.S. Navy in return for an equal number of unmodified B-24s from the U.S. Navy's allocation. The Navy would then continue to employ both its seaplane and land-based fixed-wing patrol squadrons (VP) and patrol bomber squadrons (VPB) in the antisubmarine warfare mission.
On 31 August the Air Force redesignated AAFAC as I Bomber Command and reassigned it to the First Air Force. The antisubmarine squadrons were redesignated as heavy bombardment squadrons. The 25th and 26th Antisubmarine Wings were inactivated, but the two antisubmarine groups stationed in England and French Morocco, the 479th Antisubmarine Group at RAF Dunkeswell, England and the 480th Antisubmarine Group Port Lyautey, French Morocco, continued operations into October 1943 before being inactivated.
Thus, the USAAF ended its antisubmarine mission, mostly disdained in spite of its strategic significance as temporary and secondary to the Air Force's responsibilities as a strategic bombing force.
As part of the overall Allied antisubmarine effort, the USAAF significantly affected the outcome of the campaign. In terms of the force available, the USAAF increased its antisubmarine force from a few obsolete observation aircraft, medium bombers, and B-17s, all without radar, to 187 operational B-24 Liberators, 80 B-25 Mitchells, 12 B-17 Flying Fortresss, and seven Lockheed B-34 Venturas, most equipped with microwave radar and other detection equipment. However the force was dissolved just as it reached a capability second only to escort carrier-based air operations in the ability to defeat submarines, and after the Battle of the Atlantic had peaked.
The USAAF's antisubmarine campaign harassed the Germans to the point of ineffectiveness. Even the efforts of the small armed and unarmed Civil Air Patrol aircraft in the shallow coastal waters contributed to this outcome. The German policy from the beginning of the war was to withdraw from areas that became too dangerous because of heavy aerial patrols.
By May 1943, Germany had lost the strategic initiative in the Battle of the Atlantic. Aircraft had forced the enemy to submerge so frequently and stay down for such extended intervals that their targets escaped and U-boat activity became so handicapped that the returns barely justified the expense.