|United States Army Air Forces Consolidated B-24D Liberator over Maxwell Field, Alabama.|
Maritime patrol aircraft
|First flight||29 December 1939|
|Retired||1968 (Indian Air Force)|
|Primary users||United States Army Air Forces
United States Navy
Royal Air Force
Royal Australian Air Force
|Number built||19,256|
|Variants||Consolidated PB4Y-2 Privateer
Consolidated C-87 Liberator Express
Consolidated Liberator I
|Developed into||Consolidated R2Y|
The Consolidated B-24 Liberator is an American heavy bomber, designed by Consolidated Aircraft of San Diego, California. It was known within the company as the Model 32, and some initial models were laid down as export models designated as various LB-30s, in the Land Bomber design category. The B-24 was used in World War II by every branch of the American armed forces, as well as by several Allied air forces and navies, attaining a distinguished war record with its operations in the Western European, Pacific, Mediterranean, and China-Burma-India Theaters and in antisubmarine warfare.
In comparison to the Boeing B-17 Flying Fortress, the B-24 was a more modern design, with a higher top speed, greater range, and heavier bomb load. However, it had a lower operational ceiling and was also more difficult to fly in formation at higher altitude due to heavy control forces. The shoulder placement of the B-24's high aspect ratio wing made the aircraft vulnerable to battle damage and in water landings. The B-24 was notorious among American aircrews for its tendency to catch fire. Its shoulder-mounted "Davis wing" did not provide a broad surface for emergency landings, therefore an impact on the fuselage tended to crush it and dislodge turrets. Nevertheless, the B-24 provided excellent service in a variety of roles due to its large payload and very long range. Among its varied uses, it was deployed as the carrier for the 1,000 lb Azon guided bomb.
There existed an opinion among aircrews and a tendency among some strategic bombardment commanders to favor the B-17's rugged qualities and especially its higher operational ceiling above all other considerations. However, the general staff favored the B-24 and procured it in greater numbers than any other American warplane. The B-24 remains the most produced heavy bomber in history. At nearly 19,000 units, with over 8,000 manufactured by Ford Motor Company, it holds the distinction as the most-produced American military aircraft.
The B-24's most costly mission was the low-level strike against the Ploiești oil fields, in Romania on 1 August 1943. The attack became disorganized after a navigational error which alerted the defenders and protracted the bomb run from the initial point.
Two B-24s, one B-24A and one Liberator V (Lend Lease B-24J) representing a B-24H, are airworthy as of 2015.
The Liberator originated from a United States Army Air Corps (USAAC) request in 1938 for Consolidated to produce the B-17 under license. After company executives including President Reuben Fleet visited the Boeing factory in Seattle, Washington, Consolidated decided instead to submit a more modern design of its own.
The new Model 32 combined designer David R. Davis's wing, a high-efficiency airfoil design created by unorthodox means, with the twin tail design from the Consolidated Model 31 flying boat, both mated together on a new fuselage. This new fuselage was intentionally designed around twin bomb bays, each one being the same size and capacity of the B-17 bomb bays.
In January 1939, the USAAC, under Specification C-212, formally invited Consolidated to submit a design study for a bomber with longer range, higher speed and greater ceiling than the B-17. The specification was written such that the Model 32 would automatically be the winning design. The program was run under the umbrella group, "Project A", an Air Corps requirement for an intercontinental bomber that had been conceived in the mid-1930s. Although the B-24 did not meet Project A goals, it was a step in that direction. Project A led to the development of the Boeing B-29 and Consolidated's own B-32 and B-36.
The B-24's spacious, slab-sided fuselage (which earned the aircraft the nickname "Flying Boxcar") was built around a central bomb bay that could accommodate up to 8,000 pounds (3,600 kg) of ordnance in each of its forward and aft compartments. The equal-capacity forward and aft bomb bay compartments were further split longitudinally with a centerline ventral catwalk just nine inches (23 cm) wide, which also functioned as the fuselage's structural keel beam. An unusual four-panel set of all-metal, tambour-panel "roller-type" bomb bay doors, which operated very much like the movable enclosure of a rolltop desk, retracted into the fuselage, creating a minimum of aerodynamic drag to keep speed high over the target area.
The occasional need for crewmen to move around inside from fore to aft within the B-24's fuselage during a mission over the narrow catwalk was a drawback shared with other designs.
On the ground, the B-24 was steered by using the left and right brakes and feeding power to the engines on either side. This made taxiing quite difficult.
Like the B-17, the B-24 had an array of .50 caliber (12.7 mm) M2 Browning machine guns in the tail, belly, top, sides and nose to defend it from attacking enemy fighters. However, unlike the B-17, the ball turret could be retracted into the fuselage when not in use, a necessity given the low ground clearance of the fuselage. The ball turret first appeared on B-24Ds sometime in early 1943. The early Ds had tunnel guns and the Bendix remote controlled ventral turret, of the type used on the B-25 Mitchell medium bombers and similar to the Sperry design used in early B-17E production. Other ventral defenses continued to be developed and fielded. Later the trend reversed with the ventral turret removed, resulting in a reduced crew size and weight.
The U.S. Army Air Corps awarded a contract for the prototype XB-24 in March 1939, with the requirement that one example should be ready before the end of the year. Consolidated finished the prototype and had it ready for its first flight two days before the end of 1939. The design was simple in concept but, nevertheless, advanced for its time. Consolidated incorporated innovative features such as a tricycle landing gear and Davis wing.
Compared to the B-17, the proposed Model 32 had a shorter fuselage and 25% less wing area, but had a 6 ft (1.8 m) greater wingspan and a substantially larger carrying capacity, as well as a distinctive twin tail. Whereas the B-17 used 9-cylinder Wright R-1820 Cyclone engines, the Consolidated design used twin-row, 14-cylinder Pratt & Whitney R-1830 "Twin Wasp" radials of 1,000 hp (750 kW). The 70,547 pounds (32,000 kg) maximum takeoff weight was one of the highest of the period.
The new design would be the first American bomber to use tricycle landing gear,  and it had long, thin wings with the efficient "Davis" high aspect ratio design (also used on the projected Model 31 twin-engined commercial flying boat) promising to provide maximum fuel efficiency. Wind tunnel testing and experimental programs using an existing Consolidated Model 31 provided extensive data on the flight characteristics of the Davis airfoil.
Early orders, placed before the XB-24 had flown, included 36 for the USAAC, 120 for the French Armée de l'Air and 164 for the Royal Air Force (RAF). The name "Liberator" was originally assigned to it by the RAF, and subsequently adopted by the USAAF as the official name for the Model 24. When France fell in 1940, their aircraft were re-directed to the RAF.
After initial testing, the XB-24 was found to be deficient in several areas. One major failure of the prototype was that it failed to meet the top speed requirements specified in the contract. As built, the XB-24 top speed was only 273 mph instead of the specified 311 mph. As a result, the mechanically supercharged Pratt & Whitney R-1830-33s were replaced with the turbo-supercharged R-1830s. Additionally, the tail span was widened by 2 feet (0.61 m) and the pitot-static probes were relocated from the wings to the fuselage. The XB-24 was then re-designated XB-24B—these changes became standard on all B-24s built starting with the B-24C model.
In April 1939, the USAAC initially ordered seven YB-24 under CAC contract # 12464. The US policy at the time, despite neutrality, was that American requirements could be deferred while the its Allies could immediately put US production into the war effort. The added advantage was the American types could be assessed in the Europe war zone earlier. Thus the first six YB-24 were released for direct purchase under CAC contract # F-677 on 9 November 1940. These aircraft were redesignated LB-30A. The seventh aircraft was used by Consolidated and the USAAC to test armor installations as well as self-sealing fuel tanks. Initially, these aircraft were to be given USAAC serials 39-681 to 39-687. Due to deferments of the US requirements, the US purchase was twice postponed, and the serial numbers were changed to 40-696 to 40-702. When the RAF purchased the first six YB-24 aircraft, the serial numbers were reassigned to an early batch of B-24D funded by the deferment.
The RAF, like the US, found global war increased the need for air transports and early type bombers and seaplanes were converted or completed as cargo carriers and transports. LB-30As were assigned to transatlantic flights by RAF Ferry Command, between Canada and Prestwick, Scotland. The first Liberators in British service were ex-USAAF YB-24s converted to Liberator GR Is (USAAF designation: LB-30A). The aircraft were all modified for logistic use in Montreal. Changes included the removal of all armament, provision for passenger seating, a revised cabin oxygen and heating system. Ferry Command's Atlantic Return Ferry Service flew civilian ferry pilots, who had delivered aircraft to the UK, back to North America.
Later in 1941, the first Liberator Is entered RAF service. This model introduced self-sealing fuel tanks and powered gun turrets. At the same time, Consolidated added a 2 ft 7 in (79 cm) plug in the forward fuselage to create more space for crew members.
The Liberator II (referred to as the LB-30A by the USAAF) were divided between Coastal Command, Bomber Command, and BOAC. Both BOAC and the RAF used converted Liberator IIs as unarmed long-range cargo carriers. These aircraft flew between Britain and Egypt (with an extensive detour around Spain over the Atlantic), and they were used in the evacuation of Java in the East Indies. BOAC also flew trans-Atlantic services and other various long-range air transportation routes.
Two RAF bomber squadrons with Liberators were deployed to the Middle East in early 1942. While RAF Bomber Command did not use B-24s as strategic bombers over mainland North West Europe, No. 223 Squadron RAF, one of Bomber Command's 100 (Bomber Support) Group squadrons, used 20 Liberator VIs to carry electronic jamming equipment to counter German radar.
In October 1944, two RAF Liberator squadrons (357 and 358) were deployed to Jessore India in support of British SAS, American OSS and French SIS underground operations throughout SE Asia. The aircraft were stripped of most armaments to allow for fuel for up to 26-hour return flights such as Jessore to Singapore.
Liberators were also used as anti-submarine patrol aircraft by RAF Coastal Command. RAF Liberators were also operated as bombers from India by SEAC and would have been a part of Tiger Force if the war had continued. Many of the surviving Liberators originated in this Command.
The Liberators made a great contribution to Allied victory in the Battle of the Atlantic against German U-boats. The decision to allocate some Liberators to the RAF's Coastal Command in 1941 to patrol the eastern Atlantic Ocean in an offensive anti-submarine role produced immediate results. The Very Long Range (VLR) Liberators "almost doubled the reach of Britain's maritime reconnaissance force". This extended range enabled Coastal Command anti-submarine patrols to cover part of the mid-Atlantic gap, where U-boats had operated without risk of being attacked and sunk by Allied aircraft.
For 12 months, No. 120 Squadron RAF of Coastal Command with its handful of much-patched and modified early model Liberators, supplied the only air cover for convoys in the Atlantic Gap, the Liberator being the only warplane with sufficient range. The VLR Liberators sacrificed some armor and often gun turrets in order to save weight, while carrying extra aviation gasoline in their bomb-bay tanks. Liberators were equipped with ASV (Air to Surface Vessel) Mark II radar, which together with the Leigh light gave them the ability to hunt U-boats by day and by night.
These Liberators operated from both sides of the Atlantic with the Royal Canadian Air Force and the Army Air Forces Antisubmarine Command and later, the US Navy conducting patrols along all three American coasts and the Canal Zone. The RAF and later, American patrols ranged from the east, based in Northern Ireland, Scotland, Iceland, and beginning in mid-1943 from the Azores. This role was dangerous, especially after many U-boats were armed with extra anti-aircraft guns, some adopting the policy of staying on the surface to fight, rather than submerging and risking being sunk by aerial weapons such as rockets, gunfire, torpedoes and depth charges from the bombers. In addition to flying from the US coasts, American Liberators flew from Nova Socia, Greenland, the Azores, Bermuda, the Bahamas, Puerto Rico, Cuba, Panama, Trinidad, Ascension Island and from wherever else they could fly far out over the Atlantic.
The rather sudden and decisive turning of the Battle of the Atlantic in favor of the Allies in May 1943 was the result of many factors. The gradual arrival of many more VLR and in October, PB4Y navalized Liberators for anti-submarine missions over the "black pit" and the Bay of Biscay was an important contribution to the Allies' greater success. Liberators were credited in full or in part with 93 U-boat sinkings.
In addition to very long range anti-submarine sorties, the B-24 was vital for missions of a radius less than 1,000 mi (1,600 km), in both the Atlantic and Pacific theaters where U.S. Navy PB4Y-1s and USAAF SB-24s took a heavy toll of enemy submarines and surface combatants and shipping.
The United States Army Air Forces (USAAF) took delivery of its first B-24As in mid-1941. Over the next three years, B-24 squadrons deployed to all theaters of the war: African, European, China-Burma-India, the Anti-submarine Campaign, the Southwest Pacific Theater and the Pacific Theater. In the Pacific, to simplify logistics and to take advantage of its longer range, the B-24 (and its twin, the U.S. Navy PB4Y) was the chosen standard heavy bomber. By mid-1943, the shorter-range B-17 was phased out. The Liberators which had served early in the war in the Pacific continued the efforts from the Philippines, Australia, Espiritu Santo,Guadalcanal, Hawaii, and Midway Island. The Liberator peak overseas deployment was 45.5 bomb groups in June 1944. Additionally, the Liberator equipped a number of independent squadrons in a variety of special combat roles. The cargo versions, C-87 and C-109 tanker, further increased its overseas presence, especially in Asia in support of the XX Bomber Command air offensive against Japan.
So vital was the need for long range operations, that at first USAAF used the type as transports. The sole B-24 in Hawaii was destroyed by the Japanese attack on Pearl Harbor on 7 December 1941. It had been sent to the Central Pacific for a very long range reconnaissance mission that was preempted by the Japanese attack.
The first USAAF Liberators to carry out combat missions were 12 repossessed LB-30s deployed to Java with the 11th Bombardment Squadron (7th Bombardment Group) that flew their first combat mission in mid-January. Two were shot up by Japanese fighters, but both managed to land safely. One was written off due to battle damage and the other crash-landed on a beach.
US-based B-24s entered combat service in 1942 when on 6 June, four B-24s from Hawaii staging through Midway Island attempted an attack on Wake Island, but were unable to find it. The B-24 came to dominate the heavy bombardment role in the Pacific because compared to the B-17, the B-24 was faster, had longer range, and could carry a ton more bombs.
On 12 June 1942, 13 B-24s of the Halverson Project (HALPRO) flying from Egypt attacked the Axis-controlled oil fields and refineries around Ploiești, Romania. Within weeks, the First Provisional Bombardment Group formed from the remnants of the Halverson and China detachments. This unit then was formalized as the 376th Bombardment Group, Heavy and along with the 98th BG formed the nucleus of the IX Bomber Command of the Ninth Air Force, operating from Africa until absorbed into the Twelfth Air Force briefly, and then the Fifteenth Air Force, operating from Italy. The Ninth Air Force moved to England in late 1943. This was a major component of the USSTAF and took a major role in strategic bombing. Fifteen of the 15th AF's 21 bombardment groups flew B-24s.
For much of 1944, the B-24 was the predominant U.S. Strategic Air Forces (USSTAF) formerly the Eighth Air Force in the Combined Bomber Offensive against Germany, forming nearly half of its heavy bomber strength in the ETO prior to August and most of the Italian-based force. Thousands of B-24s, flying from bases in Europe dropped hundreds of thousands of tons of high explosive and incendiary bombs on German military and industrial targets.
The 44th Bombardment Group was one of the first two heavy bombardment groups flying the B-24 with the 8th Air Force in the fall/winter air campaigns in the European Theater of Operations. The 44th Bomb Group flew the first of its 344 combat missions against the Axis powers in World War II on 7 November 1942.
The first B-24 loss over German territory occurred on 26 February 1943. Earlier in the war, both the German Luftwaffe and the British Royal Air Force had abandoned daylight bombing raids because neither could sustain the losses suffered. The Americans persisted, however, at great cost in men and aircraft. In the period between 7 November 1942 and 8 March 1943, the 44th Bomb Group lost 13 of its original 27 B-24s. For some time, newspapers had been requesting permission for a reporter to go on one of the missions. Robert B. Post and five other reporters of The New York Times were granted permission. Post was the only reporter assigned to a B-24-equipped group, the 44th Bomb Group. He flew in B-24 41-23777 ("Maisey") on Mission No. 37 to Bremen, Germany. Intercepted just short of the target, the B-24 came under attack from JG 1's Messerschmitt Bf 109s. Leutnant Heinz Knoke (who finished the war with 31 kills) shot down the Liberator. Post and all but two of the 11 men aboard were killed. Knoke reported: "The fire spread out along the right wing. The inboard propeller windmilled to a stop. And then, suddenly, the whole wing broke off. At an altitude of 900 metres there was a tremendous explosion. The bomber had disintegrated. The blazing wreckage landed just outside Bad Zwischenahn airfield," which would later be used for some of the first Messerschmitt Me 163B Komet rocket fighter operations.
A total of 177 B-24s carried out the famous second attack on Ploești (Operation Tidal Wave) on 1 August 1943, flying from their bases in northwestern Libya. In late June 1943, the three B-24 Liberator groups of the 8th Air Force were sent to North Africa on temporary duty with the 9th Air Force. The 44th Bomb Group was joined by the 93rd and the 389th Bomb Groups. These three units joined the two 9th Air Force B-24 Liberator groups for the 1 August 1943 low-level attack on the German-held Romanian oil complex at Ploești. This daring assault by high altitude bombers at tree top level was a costly success. The 44th destroyed both of its assigned targets, but lost 11 of its 37 bombers and their crews. Colonel Leon W. Johnson, the 44th's commander, was awarded the Medal of Honor for his leadership, as was Col. John Riley "Killer" Kane, commander of the 98th Bomb Group. Kane and Johnson survived the mission but three other recipients of the Medal of Honor for their actions in the mission—Lt. Lloyd H. Hughes, Maj. John L. Jerstad and Col. Addison E. Baker—were killed in action. For its actions on the Ploești mission, the 44th was awarded its second Distinguished Unit Citation. Of the 177 B-24s that were dispatched on this operation, 54 were lost.
The B-24 advanced the use of electronic warfare and equipped Search Bomber (SB), Low Altitude (LAB) and Radar Counter Measure (RCM) squadrons in addition to high altitude bombing. Among the specialized squadrons were the 20th RS (RCM), 36th BS (RCM), 406th NLS, 63rd BS (SB) SeaHawks, 373rdBS (LAB) and 868th BS (SB) Snoopers.
The 36th Bombardment Squadron was the Eighth Air Force's only electronic warfare squadron using specially equipped B-24s to jam German VHF communications during large Eighth Air Force daylight raids. In addition, the 36th BS flew night missions with the Royal Air Force Bomber Command 100 Group at RAF Sculthorpe. Radar Counter Measures (RCM) was code named CARPET, however, this should not be confused with agent and supply drops, code named "Carpetbaggers".
The B-24 controlled Azmuith Only Azon, a pioneering Allied radio guided munitions during World War II. The ordnance of 1,000 lb weight, was deployed operationally by USAAF B-24s in both Europe and the CBI theaters. The Eighth Air Force's 458th Bombardment Group deployed the guided Azon ordnance in Europe between June and September 1944, while the Tenth Air Force's 493rd Bomb Squadron employed it against Japanese railroad bridges on the Burma Railway in early 1945, fulfilling the intended original purpose of the Azon system.
In February 1944, the 2nd Division authorized the use of "Assembly Ships" (or "Formation Ships") specially fitted to aid assembly of individual group formations. They were equipped with signal lighting, provision for quantity discharge of pyrotechnics, and were painted with distinctive group-specific high-contrast patterns of stripes, checkers or polka dots to enable easy recognition by their flock of bombers. The aircraft used in the first allocation were B-24Ds retired by the 44th, 93rd and 389th Groups. Arrangements for signal lighting varied from group to group, but generally consisted of white flashing lamps on both sides of the fuselage arranged to form the identification letter of the group. All armament and armor was removed and in some cases the tail turret. In the B-24Hs used for this purpose, the nose turret was removed and replaced by a "carpetbagger" type nose. Following incidents when flare guns were accidentally discharged inside the rear fuselage, some assembly (formation) ships had pyrotechnic guns fixed through the fuselage sides. As these aircraft normally returned to base once a formation had been established, a skeleton crew of two pilots, navigator, radio operator and one or two flare discharge operators were carried. In some groups an observer officer flew in the tail position to monitor the formation. These aircraft became known as Judas goats.
From August 1943 until the end of the war in Europe, specially modified B-24Ds were used in classified missions. In a joint venture between the Army Air Forces and the Office of Strategic Services (OSS) code named Operation Carpetbagger, pilots and crews flew specially modified B-24Ds painted with a glossy black anti-searchlight paint to supply friendly underground forces throughout German occupied Europe. They also flew C-47s, Douglas A-26 Invaders, and British de Havilland Mosquitos.
Carpetbagger aircraft flew spies called "Joes" and commando groups prior to the Allied invasion of Europe on D-Day and afterward, and retrieved over 5,000 officers and enlisted men who had escaped capture after being shot down. The low-altitude, nighttime operation was extremely dangerous and took its toll on these airmen. The first aircrews chosen for this operation came from the anti-submarine bomb groups because of their special training in low altitude flying and pinpoint navigation skills. Because of their special skills, they were called upon to fly fuel to General George Patton's army during the summer and early autumn of 1944 when it outran its fuel supply. When this mission was completed, it was recorded that 822,791 US gallons (3,114,264 L) of 80 octane gasoline had been delivered to three different airfields in France and Belgium.
The 859 BS was converted from day bombadment to these operations and then transferred to the 15th Air Force.
In early 1942, with the need for a purpose-built transport with better high altitude performance and longer range than the Douglas C-47 Skytrain, the San Diego plant begand sending B-24D to Fort Worth for conversion into the C-87 transport. The conversion had a hinged cargo door at the nose eliminating transparent nose and large cargo doors installed in the waist area. The C-87 had a large cargo floor, less powerful supercharged engines, no gun turrets, a floor in the bomb bay for freight, and some side windows. The navigator's position was relocated behind the pilot. Indigenous Fort Worth C-87 and AT-22 production began with the FY 1943 order for 80 serial numbered airframes 43-30548 through 43-30627.
The C-87A was a dedicated VIP series built in small quantity. Early versions were fitted with a single .50 caliber (12.7 mm) Browning machine gun in their tails, and a XC-87B version proposed two .50 caliber (12.7 mm) fixed machine guns for the nose, operable by the pilot, though these were eventually removed. The XC-87B also designated a resurrected crash victim B-24D (42-40355) fitted with low altitude power packages and a forward fuselage extension. The extended nose earned it the name Pinocchio. Later modifications gave it a single tail and yet another type of engine packages bring it to near C-87C configuration. Other C-87 designations were the U.S. Navy designation RY and Lend Lease Liberator Cargo VII.
Although only 287 C-87 and eight U.S. Navy RY variants were produced, they were still important in the Army Air Forces' airlift operations early in the war when aircraft with high altitude, long-range heavy hauling abilities were in short supply. The C-87 flew in many theaters of war, including much hazardous duty in flights from Labrador to Greenland and Iceland in the North Atlantic. In the China Burma India Theater (CBI), the C-87 was used to airlift cargo and fuel over the Hump (the Himalayas) from India to China. Early in the campaign, the C-87 was the only readily available American transport that could fly over the Himalayas while heavily loaded, rather than relying on circuitous and highly dangerous routes through valleys and mountain passes. The ATC India China Division was the only unit in the Command to be combat decorated during WWII, having been award a Distinguished Unit Citation.
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The C-87 was not always popular with the aircrews assigned to fly it. The aircraft had the distressing habit of losing all cockpit electrical power on takeoff or at landings, its engine power and reliability with the less-powerful superchargers also often left much to be desired. It proved to be quite vulnerable to icing conditions, and was prone to fall into a spin with even small amounts of ice accumulated onto its Davis wing. Since the aircraft had been designed to be a bomber that dropped its loads while airborne, the C-87's nose landing gear was not designed for landing with a heavy load, and frequently it collapsed from the stress. Fuel leaks inside the crew compartment from the hastily modified long-range fuel system were an all-too-common occurrence. Lastly, unlike a typical purpose-designed transport, the B-24 was not designed to tolerate large loading variations because most of its load was held on fixed bomb racks. Consequently, it was relatively easy for a poorly trained ground crew to load a C-87 with its center of gravity too far forward or aft, rendering the aircraft difficult to control due to inadequate or excessive longitudinal stability. In his autobiography, Fate is the Hunter, the writer Ernest K. Gann reported that, while flying air cargo in India, he barely avoided crashing an improperly loaded C-87 into the Taj Mahal. As soon as more dependable Douglas C-54 Skymaster and Curtiss-Wright C-46 Commando transports became available in large numbers, C-87s were rapidly phased out of combat zone service , with some later used as VIP transports or B-24 flight crew trainers.
The C-109 was a dedicated fuel transport version of the B-24 conceived as a support aircraft for Boeing B-29 Superfortress operations in central China. Unlike the C-87, the C-109 was not built on the assembly line, but rather was converted from existing B-24 bomber production; to save weight, the glass nose, armament, turret fairings and bombardment equipment were removed. Several storage tanks were added, allowing a C-109 to carry almost 2,905 gal (11,000 L) of fuel weighing over 22,000 pounds (10,000 kg).
Plans originally called for 2,000 C-109s to support 10 groups of B-29s (approximately 400) in China, but the capture of the Mariana Islands provided a far more easily resupplied location for raids on mainland Japan, and the plans were greatly scaled back. Only 218 C-109s were actually converted. After the transfer of the B-29s, the C-109s were reassigned to the Air Transport Command. According to the history of the U.S. Army Air Forces in World War II, at least one squadron was assigned to the IX Troop Carrier Command in Europe to transport gasoline to advancing ground and air forces on the Continent after the Normandy invasion.
However, whereas a combat-loaded B-24 could safely take off with room to spare from a 6,000 ft (1,800 m) runway, a loaded C-109 required every foot of such a runway to break ground, and crashes on takeoff were not uncommon. The aircraft demonstrated unstable flight characteristics with all storage tanks filled, and proved very difficult to land fully loaded at airfields above 6,000 ft (1,800 m) MSL in elevation, such as those around Chengdu. After it was discovered that these problems could be alleviated by flying with the forward storage tank empty, this practice became fairly routine, enhancing aircrew safety at the cost of some fuel-carrying capacity. Many C-109s were lost in flying the Hump airlift to China.
B-24 bombers were also extensively used in the Pacific area after the end of World War II to transport cargo and supplies during the rebuilding of Japan, China, and the Philippines.
B-24s were also used by the U.S. Navy and U.S. Marine Corps for ASW, anti-ship patrol, and photographic reconnaissance in the Pacific Theater, and by the U.S. Coast Guard for patrol and SAR. Naval B-24s were redesignated PB4Y-1, meaning the fourth patrol bomber built by Consolidated Aircraft. Navy PB4Y-1s assigned to Atlantic ASW and all Coast Guard PB4Y-1s had the ventral turret replaced by a retractable radome. Also, most naval aircraft had an Erco ball turret installed in the nose position, replacing the glass nose and other styles of turret.
The Consolidated Aircraft Company PB4Y-2 Privateer was a World War II U.S. Navy patrol bomber that was derived directly from the B-24 Liberator. The U.S. Navy had been using basically unmodified B-24s as the PB4Y-1 Liberator, and this type of patrol plane was considered to be quite successful. However, a fully navalized design was advantageous, and Consolidated Aircraft developed a purpose-built long-range patrol bomber in 1943, designated PB4Y-2, that was visually distinguishable from the B-24 and PB4Y-1 by having a single vertical stabilizer rather than a twin tail, and teardrop-shaped waist gun blisters, much like those on Consolidated's own PBY Catalina flying boat maritime patrol aircraft in appearance.
While Australian pilots flew Liberators in other theatres of war, the aircraft was introduced into service in the Royal Australian Air Force (RAAF) in 1944, after the American commander of the Far East Air Forces (FEAF) General George C. Kenney suggested that seven heavy bomber squadrons be raised to supplement the efforts of the 380th Bombardment Group of the USAAF. The USAAF helped in the procurement of the aircraft for the RAAF and training of the Australian aircrew members. Seven flying squadrons, an operational training unit and two independent flights were equipped with the aircraft by the end of World War II in August 1945. Liberators remained in service until 1948.
The RAAF Liberators saw service in the South West Pacific theatre of World War II. Flying mainly from bases in the Northern Territory, Queensland and Western Australia the aircraft conducted bombing raids against Japanese positions, ships and strategic targets in New Guinea, Borneo and the Netherlands East Indies. In addition, the small number of Liberators operated by No. 200 Flight played an important role in supporting covert operations conducted by the Allied Intelligence Bureau; and other Liberators were converted to VIP transports. A total of 287 B-24D, B-24J, B-24L and B-24M aircraft were supplied to the RAAF, of which 33 were lost in action with more than 200 Australians killed. Following the Japanese surrender the RAAF's Liberators participated in flying former prisoners of war and other personnel back to Australia.
In June 1944, Qantas Empire Airways began service with the first of two converted Liberators on the Perth to Colombo route to augment Consolidated PBY Catalinas that had been used since May 1943. This route across the Indian Ocean was 3,513 mi (5,654 km) long, the longest non-stop airline route in the world at the time. The Liberators flew a shorter 3,077 mi (4,952 km) over-water route from Learmonth to an airfield northeast of Colombo, but they could make the flight in 17 hours with a 5,500 pounds (2,500 kg) payload, whereas the Catalinas required 27 hours and had to carry so much auxiliary fuel that their payload was limited to only 1,000 pounds (450 kg). The route was named Kangaroo Service and marked the first time that Qantas' now-famous Kangaroo logo was used; passengers received a certificate proclaiming them as members of The Order of the Longest Hop. The Liberators were later replaced by Avro Lancastrians.
Two squadrons of the South African Air Force (SAAF) also flew B-24s: 31 and 34 Squadrons under No 2 Wing SAAF based at Foggia, Italy. These two squadrons engaged in relief flights to Warsaw and Kraków in Poland to support the Polish Uprising against Nazi Occupation.
Three B-24s were captured and then operated by the German secret operations unit KG 200, which also tested, evaluated and sometimes clandestinely operated captured enemy aircraft during World War II.
One of these was captured at Venegono, Italy on March 29, 1944. It was used on penetration missions in RAF bomber streams at night in Luftwaffe markings. On a ferry flight from Hildesheim to Bavaria on April 6, 1945 it was shot down - by German anti-aircraft fire.
Only one B-24 was officially delivered to the USSR according to the Lend-Lease agreements, stranded in Yakutsk while flying a government mission to the Soviet Union in November 1942. In addition, 73 Liberators of various models that had force-landed on European airfields were recovered and 30 of them were repaired and used by the 45th BAD.
The B-24 Bombers joined the Chinese Battlefield since 1942 as the heavy bombers of the 14 th Airforce to fight against the Japanese during the Second Sino-Japanese War (WW2 in China). About 48 B-24Ms were provided by the U.S. to the Chinese Nationalists Airforce after WW2 and were used during the Chinese Civil War. The PLAAF had two B-24Ms captured from the Chinese Nationalists during the Chinese Civil War and operated until 1952.
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Continued development work by Consolidated produced a handful of transitional B-24Cs with turbocharged instead of supercharged engines. The turbocharged engines led to the flattened oval nacelles that distinguished all subsequent Liberator models.
The B-24D was the first mass-produced series. The B-24D was the Liberator III in British service. It entered US service in early 1942. It had turbocharged engines and increased fuel capacity. Three more 0.50 caliber (12.7 mm) machine guns brought the defensive armament up to 10 machine guns. At 59,524 pounds (27,000 kg) maximum takeoff weight, it was one of the heaviest aircraft in the world; comparable with the British "heavies", with fully loaded weights of nearly 30 short tons for the Stirling, the 34 short ton Lancaster and the 27 short ton Halifax.
Production of B-24s increased at an astonishing rate throughout 1942 and 1943. Consolidated Aircraft tripled the size of its plant in San Diego and built a large new plant outside Fort Worth, Texas. More B-24s were built by Douglas Aircraft in Tulsa, Oklahoma. The North American plant B in the city of Grand Prairie, Texas started production of B-24G in 1943. None of these were minor operations, but they were dwarfed by the vast new purpose-built factory constructed by the Ford Motor Company at Willow Run near Detroit, Michigan.
Ford broke ground on Willow Run in the spring of 1941, with the first plane coming off the line in October 1942. It had the largest assembly line in the world (3,500,000 sq ft; 330,000 m2). At its peak in 1944, the Willow Run plant produced one B-24 per hour and 650 B-24s per month. By 1945, Ford made 70% of all B-24s in two nine-hour shifts. Pilots and crews slept on 1,300 cots at Willow Run waiting for their B-24s to roll off the assembly line. At Willow Run, Ford produced half of 18,000 total B-24s.
Each of the B-24 factories was identified with a production code: Consolidated/San Diego, CO; Consolidated/Fort Worth, CF; Ford/Willow Run, FO; North American, NT; and Douglas/Tulsa, DT.
In 1943, the model of Liberator considered by many the "definitive" version was introduced. The B-24H was 10 inches (25 cm) longer, had a powered gun turret in the upper nose to reduce vulnerability to head-on attack, and was fitted with an improved bomb sight, autopilot, and fuel transfer system. Consolidated, Douglas and Ford all manufactured the B-24H, while North American made the slightly different B-24G. All five plants switched over to the almost identical B-24J in August 1943. The later B-24L and B-24M were lighter-weight versions and differed mainly in defensive armament.
As the war progressed, the complexity of servicing the Liberator continued to increase. The B-24 variants made by each company differed slightly, so repair depots had to stock many different parts to support various models. Fortunately, this problem was eased in the summer of 1944, when North American, Douglas and Consolidated Aircraft at Fort Worth stopped making B-24s, leaving only the Consolidated plant in San Diego and the Ford plant in Willow Run.
In all, 18,482 B-24s were built by September 1945. Twelve thousand saw service with the USAAF, with a peak inventory in September 1944 of 6,043. The U.S. Navy received 977 PB4Y-1s (Liberators originally ordered by the USAAF) and 739 PB4Y-2 Privateers, derived from the B-24. The Royal Air Force received about 2,100 B-24s equipping 46 bomber groups and 41 squadrons; the Royal Canadian Air Force (RCAF) 1,200 B-24Js; and the Royal Australian Air Force (RAAF) 287 B-24Js, B-24Ls, and B-24Ms. Liberators were the only heavy bomber flown by the RAAF in the Pacific.
Late in the war RAF Liberator aircraft modified in England for use in South East Asia had the suffix "Snake" stenciled below the serial number to give them priority delivery through the Mediterranean and Middle East.
Data from Quest for Performance
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