History
Background
The development of the Liberator began when the US Army Air Corps issued a request in 1938 for Consolidated Aircraft to produce the B-17 Flying Fortress under license. After visiting Boeing’s Seattle factory and inspecting the B-17 firsthand, Consolidated instead proposed a superior design of its own to compete directly with Boeing’s bomber.
In January 1939, the Army Air Corps invited Consolidated to submit a formal design for a long-range heavy bomber that offered better range, speed, and service ceiling than the B-17. This led to the Model 32 proposal, featuring a highly efficient airfoil wing, a twin tail, and twin bomb bays, each equal in capacity to the B-17’s single bay. It was to be powered by four Pratt & Whitney R-1830-33 engines, equipped with mechanical two-speed superchargers but no turbosuperchargers.
Following review, the Army awarded a contract for one prototype, designated XB-24, on March 30, 1939. In less than nine months, the XB-24 made its maiden flight on December 29, 1939. Even before it flew, the Army had already placed orders for seven YB-24s and thirty-six B-24As for evaluation. The XB-24 was transferred to Wright Field, Ohio, for testing, where extensive evaluations led to a series of refinements before it was officially accepted by the Army on August 13, 1940.
French & British Orders
In May 1938, a delegation from the French Purchasing Commission visited Consolidated and issued a specification for an export version of the Model 32, designated LB-30MF (“Mission Française”), with “LB” standing for “Land Bomber.” In April 1940, France expressed a strong interest in the aircraft and placed an order for 175 examples. However, the fall of France in June 1940 rendered the order moot, and the contract was transferred to Great Britain.
Under this revised contract, the first six YB-24 airframes were completed to British specifications and delivered as LB-30As, which were assigned to Ferry Command for use as long-range transports. These were operated by British Overseas Airways Corporation crews on transatlantic routes. The American equivalent, the B-24A, was also used for similar transport purposes.
The next twenty aircraft, built from diverted B-24A production, became known as LB-30Bs or Liberator Mk.Is in RAF service. These were the first Liberators to see operational combat, entering service with No. 120 Squadron of Coastal Command by summer 1941. Modifications included ASV (air-to-surface vessel) radar antennas, racks for depth charges, and in some cases, a 20 mm cannon pack fitted under the forward fuselage for anti-submarine warfare.
Requisitioning the LB-30 (Liberator Mk.II) Liberator
The next version, the Liberator Mk.II, was the first purpose-built Liberator bomber variant for the RAF and had no direct American counterpart. It incorporated significant structural change, a lengthened nose (adding approximately three feet), which became standard for all later Liberator models. These aircraft also introduced power-operated defensive armament: two Boulton Paul turrets, each armed with four .303-caliber Browning machine guns, were fitted in the tail and upper fuselage.
Fuel tanks and fuel lines were now self-sealing for improved survivability, and the earlier Hamilton Standard propellers were replaced by longer-hub Curtiss Electric propellers. A total of 140 Liberator Mk.IIs were built specifically to RAF specifications, rather than being diverted from US orders. While some were delivered unarmed, they were fitted with British equipment and weaponry upon arrival at RAF bases.
The Liberator Mk.II formally entered RAF service in August 1941, following a delay caused by the tragic crash of the first aircraft, AL503, which was scheduled for delivery on June 2, 1941. During a test flight, a loose bolt jammed the elevator, causing the aircraft to crash into San Diego Bay and killing all on board, including Consolidated’s chief test pilot, William Wheatley.
Following the attack on Pearl Harbor on December 7, 1941, and America’s entry into the war, the US Army urgently requisitioned 75 of the 140 Liberator Mk.IIs originally intended for the RAF. These aircraft, delivered unarmed and unfinished to RAF standards, were redesignated LB-30 by the US Army Air Forces, instead of being classified as “B-24”. This designation reflected the fact that they were originally built for export. They were repainted with US national insignia but retained their RAF serial numbers and camouflage, Dark Earth and Dark Green over Night Black, which remained until repaints or overhauls.
Once in US hands, the aircraft were modified with American equipment and weapons. The RAF-specified Boulton Paul power turrets were replaced: a powered Martin turret armed with twin .50 caliber machine guns was installed in the mid-upper fuselage, while the tail position was fitted with a pair of hand-held .50 caliber guns. Additional single .50 caliber guns were mounted in the waist positions and the nose. In total, the modified LB-30s carried eight 0.50 caliber machine guns.
Of the 75 aircraft taken over by the USAAF, 46 were pressed into active service. Six were lost to accidents within the first six weeks of operations, while the remaining 23 were eventually returned to the RAF once newer US-built Liberator models became available.
In January 1942, 15 LB-30s were deployed to Java to reinforce the B-17-equipped 7th and 19th Bomb Groups, flying in desperate defense of the Dutch East Indies. Seventeen more were equipped with Canadian-built ASV radar and assigned to Latin America, reinforcing the 6th Bomb Group tasked with defending the Panama Canal. Three LB-30s were deployed to Alaska, where they joined the 28th Composite Group for anti-shipping patrols against the Japanese in the Aleutians. Those not used in combat were converted into training aircraft or long-range transports serving with Ferry Command across both Atlantic and Pacific routes.
The first US-flown Liberators to see combat were LB-30s in Java. On January 16, 1942, three LB-30s and two B-17s of the 9th Bomb Group carried out a raid on Japanese shipping and airfields from Singosari near Malang, Java. Soon after, surviving aircraft were evacuated to India, from where they resumed operations against Japanese forces in Burma. LB-30s of the 19th Bomb Group also struck targets in Sumatra, Bali, and the Celebes (now Sulawesi) in an effort to disrupt the Japanese advance. After the fall of the Dutch East Indies, surviving aircraft were withdrawn to Australia, with at least two LB-30s surviving long enough to be converted into C-87 Liberator Express transports by 1944.
Although soon eclipsed by newer models such as the B-24D, some aircraft continued to serve in the Panama Canal Zone until as late as 1944, flying coastal defense and anti-submarine patrols.
