In 1938 Consolidated Aircraft was approached by by United States Army Air Corps to augment the Boeing plant in Seattle in the production of B-17 bombers. However, after touring the Boeing plant Consolidated engineers submitted a design of their own, which would be the most versatile bomber of World War II – the B-24 Liberator. During this blog we’ll trace the development of the Liberator, as well as the many roles it played during the war.
Capitalizing on its success in building large flying boat aircraft in the 1930′s, Consolidated based the design of the Model 32 upon a shoulder-mounted Davis wing. This concept proved highly efficient, giving the Liberator a high aspect ratio, in addition to greater speed, load and range. The fuselage of the Liberator was structured around its bomb bays, with the forward and rear bomb bay compartments split lengthwise with a center line ventral catwalk, which also served as the fuselage’s structural keel beam. A unique feature of the Liberator was it’s bomb bay doors. Instead of having flap type doors, as with the B-17, the Liberator had a set of four tambour-panel metal bomb bay doors, which retracted up the outside fuselage of the plane, closing similar to the slide action of a roll top desk. The reasons for this concept were retraction of the doors along the fuselage minimized drag, allowing the plane to fly over the target area at a high rate of speed, while maximizing ground clearance since the Liberator design was too low to allow the use of conventional bomb bay doors. The aft fuselage was mated to a small wing with two tails, as with the earlier Model 31 flying boat. The Liberator also had the distinction of being the first USAAF bomber to incorporate a tricycle landing gear system.
Designated by Consolidated as the B-24 in 1939, the Liberator began operations with the RAF the following year as a transport flying equipment and civilian ferry pilots between Canada and Britain. The Liberators serving inPB4Y P this role were modified with the removal of armament and the placement of passenger seats and a revised cabin oxygen and heating system. Liberators also tipped the scales in the Battle Of The Atlantic. The delivery of Very Long Range (VLR) Liberators to the RAF Coastal Command in 1941 drastically increased the range of the RAF patrol force, closing the Mid Atlantic Gap, an area of the Atlantic in which U boats could operate free from air attack due to the limited range of existing patrol aircraft. These B-24s were stripped of non-essential armament in order to save weight and carried additional fuel tanks in the bomb bay to extend the range of the plane. By 1942 these Liberators carried ASV (Air to Surface Vessel) radar, which coupled with the Leigh searchlight mounted under the wing, achieved a stunning rate of success against the U boats, with many U boat crews choosing to charge their batteries during daylight when they could see approaching aircraft.
The B-24′s first combat missions as a bomber were flown by the RAF in the Middle East in early 1942. Though the missions were successful, the RAF never deployed the Liberator in a strategic role over Europe. While the first combat for the Liberator with the USAAF was a failed mission against Wake Island in June 1942, within a week B-24s from an Egyptian base launched a raid against the Ploesti oil fields in Romania. Though small in scope, this raid was a precursor of things to come. This effort was followed up by another mission against Ploesti on August 1, 1943. Operation Tidal Wave was the B-24′s most costly mission. In June 1943, three B-24 groups were detailed from the Eighth Air Force in England to train with two B-24 groups from the Ninth Air Force to conduct the mission. Flying from bases in North Africa, the joint force was to approach the Ploesti complex at low altitude in order to gain surprise over enemy fighters. However, the attack became disorganized after a navigational error alerted the defenders, lengthening the bomb run. Though much of the refinery was destroyed, it was producing at total capacity within a few months. This was achieved at a loss of 54 Liberators of the 177 assigned to the mission. It would take several missions flown by B-24s of the newly formed Fifteenth Air Force to completely destroy the Ploesti refinery the following year.
In 1943 the B-24 received a significant update with nose turrets installed on the H and J models, which were just entering production. This was a marked improvement over the earlier D model, introduced in USAAF service in early 1942, having a web type front housing with two poke guns. The powered Emerson turret enabled the Liberator to reduce vulnerability to head-on attacks. The H and J models also featured an improved bomb sight and fuel transfer system. The J model offered slight improvements in the bomb sight and autopilot over the H model and became the primary B-24 production model from August 1943 through the remainder of the war. The Liberator became the dominant heavy bomber in the Pacific due to it’s greater range, payload and speed over the B-17, which was phased out by mid 1943. Unlike the operations of the European theater, little strategic bombing was conducted in the Pacific by the Fifth and Seventh Air Forces, with the majority of the missions flown in support of ground forces. As with the RAF, Liberators in the China, Burma, India (CBI) area were used in a transport role. The converted cargo version, designated C-87, was used to airlift cargo over the Himalayas from India to China. This was of critical importance early in the war, as the Liberator was the only USAAF transport immediately available which could fly over the Himalayas fully loaded. A tanker model of the B-24 was also utilized in the CBI area. The C-109 became operational in the summer of 1944 as a support aircraft for Boeing B-29 Superfortress operations launched from Chinese bases. Unlike the C-87, the C-109 was not built on the assembly line, but converted in the field from existing B-24 production. These modifications included the addition of several storage tanks, giving the 109 a capacity of 22,000 lbs. of fuel. When fully loaded these aircraft proved difficult to fly, which dictated leaving the forward tanks empty. While plans originally envisioned a fleet of 2,000 C-109 tankers to support 10 B-29 groups operating from China, the capture of the Mariana Islands offered a much easier location from which to supply raids on mainland Japan.
During its service the Liberator played a number of roles. A dedicated naval version, the PB4Y Privateer, a single-tailed aircraft, was used by the navy in both the Atlantic and Pacific areas. The B-24 was one of the first aircraft to use a precision-guided bomb, as well as jamming radar in flight. From service as a VIP transport to bombing U boats in the Atlantic, the Liberator was there. The B-24 was used by at least six Allied nations with more than a dozen versions produced. When production ended in 1945, the Liberator was both the most diverse and the most produced USAAF aircraft of World War II-with more than 18,500 examples built.
DEDICATED TO JON GARVIS