The Consolidated PB4Y-2 Privateer is an American World War II and Korean War era patrol bomber of the United States Navy derived from the Consolidated B-24 Liberator. The Navy had been using B-24s with only minor modifications as the PB4Y-1 Liberator, and along with maritime patrol Liberators used by RAF Coastal Command this type of patrol plane was proven successful. A fully navalised design was desired, and Consolidated developed a dedicated long-range patrol bomber in 1943, designated PB4Y-2 Privateer. In 1951, the type was redesignated P4Y-2 Privateer. A further designation change occurred in September 1962, when the remaining Navy Privateers (all having previously been converted to drone configuration as P4Y-2K) were redesignated QP-4B. The Privateer was externally similar to the Liberator, but the fuselage was longer to accommodate a flight engineer's station, and it had a tall single vertical stabilizer rather than the B-24's twin tail configuration. The Navy wanted a flight engineer crewmember to reduce pilot fatigue on long duration over water patrols. The single vertical tail was adopted from the USAAF's canceled B-24N design (and was slightly taller on the Privateer) because it would increase stability at low to medium altitudes for maritime patrol. The Ford Motor Company, which produced B-24s for the United States Army Air Forces, had earlier built an experimental variant (B-24K) using a single tail. Aircraft handling was improved. The single tail design was used on the B-32 Dominator and PB4Y-2 and was slated for the US Army Air Forces' proposed B-24N production model to be built by Ford, but that order (for several thousand bombers) was canceled on 31 May 1945. Defensive armament on the PB4Y-2 was increased to twelve .50-in (12.7 mm) M2 Browning machine guns in six power-operated turrets (two dorsal, two waist, nose and tail); the B-24's ventral, retractable Sperry ball turret was omitted. Turbosuperchargers were not fitted to the Privateer's engines since maritime patrol missions were not usually flown at high altitude, improving performance and also saving weight. For more details on development and operational history, click here. Variants. YPB4Y-2 prototypes, three built. PB4Y-2 (Specifications below) main production version, 736 built. PB4Y-2B PB4Y-2s equipped to launch ASM-N-2 Bat air-to-surface missiles. Redesignated P4Y-2B in 1951. PB4Y-2M PB4Y-2s converted for weather reconnaissance. Redesignated P4Y-2M in 1951. PB4Y-2S PB4Y-2s equipped with anti-submarine radar. Redesignated P4Y-2S in 1951. PB4Y-2G PB4Y-2s converted for air-sea rescue and weather reconnaissance duties with the U.S. Coast Guard. Redesignated P4Y-2G in 1951. PB4Y-2K PB4Y-2s converted to target drones. Redesignated P4Y-2K in 1951 and QP-4B in 1962.