Consolidated B-24 Liberator

The Consolidated B-24 Liberator was an American heavy bomber, built by Consolidated Aircraft. It was produced in greater numbers than any other American combat aircraft of World War II and still holds the record as the most produced U.S. military aircraft. It was used by many Allied air forces and every U.S. branch of service during the war, attaining a distinguished war record with its operations in the northern European, Pacific and Mediterranean theaters. 

Often compared to the better known B-17 Flying Fortress, the B-24 was a more modern design with a higher top speed and greater range yet it had a similar bomb load and defensive armament. Nevertheless, popular opinion among aircrews and general staff tended to favor the B-17s rugged qualities above all other considerations. The B-24 was notorious among American air crews for its tendency to catch fire. The placement of B-24 fuel tanks throughout the upper fuselage and its lightweight construction, designed both to increase range and optimize assembly line production, made the aircraft vulnerable to battle damage. The B-24 was more difficult to fly as well, with heavy control forces and poor formation flying characteristics. The B-24 nevertheless provided excellent service in a variety of roles thanks to its large payload and long range.

Consolidated B-24 Liberator
Class Aircraft
Type Bomber
Manufacturer Consolidated Aircraft
Origin United States of America
Country Name Origin Year
United States of America 1939
Country Name Operational Year Retirement Year
Australia View
Brazil View
Canada View
China View
Czechoslovakia View
Germany View
India 1941 1968 View
Italy View
Netherlands View
Nicaragua View
Poland View
Portugal View
Romania View
Russia (USSR) View
South Africa View
Turkey (Ottoman Empire) View
United Kingdom - UK (Great Britain) View
United States of America 1941 View
ManufacturerName Production From Production To Quantity
Consolidated Aircraft 18482 View

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.

RAF

The first British Liberators had been ordered by the Anglo-French Purchasing Board in 1940. After the Fall of France the French orders were in most cases transferred to Britain.

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.

The most important role, however, for the first batch of the Liberator GR Is was in service with RAF Coastal Command on anti-submarine patrols in the Battle of the Atlantic.

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.

Antisubmarine and maritime patrols

AAF Antisubmarine Command (AAFAC) modifications at the Consolidated-Vultee Plant, Fort Worth, Texas in the foreground in the olive drab and white paint scheme. To the rear of this front line are partly assembled C-87 "Liberator Express Transports".

Anti-Submarine Weapons: Leigh light used for spotting U-boats on the surface at night, fitted to a Liberator aircraft of Royal Air Force Coastal Command. 26 February 1944.

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 Scotia, 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.

USAAF

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.

Strategic bombing, 1942–45

On 12 June 1942, 13 B-24s of the Halverson Project (HALPRO) flying from Egypt attacked the Axis-controlled oil fields and refineries around Ploie?ti, 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 Ploie?ti (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 Ploie?ti. 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 Ploie?ti mission, the 44th was awarded its second Distinguished Unit Citation. Of the 177 B-24s that were dispatched on this operation, 54 were lost.

Radar and Electronic warfare

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.

Assembly ships

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.

"Carpetbaggers"

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.

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 began sending B-24D models 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.

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.

C-109 version

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.

Role Heavy bomber
Anti-submarine warfare
Maritime patrol aircraft
Manufacturer Consolidated Aircraft
First flight 29 December 1939
Introduction 1941
Retired 1968 (Indian Air Force)
Primary users United States Army Air Forces
United States Navy
Royal Air Force
Royal Canadian Air Force
Produced 1940–1945
Number built 19,256
Unit cost $297,627 ($4.77 million in today's dollars)
Variants Consolidated PB4Y-2 Privateer
Consolidated C-87 Liberator Express
Consolidated Liberator I
Developed into Consolidated R2Y


General characteristics

  • Crew: 7-10
  • Length: 67 ft 8 in (20.6 m)
  • Wingspan: 110 ft 0 in (33.5 m)
  • Height: 18 ft 0 in (5.5 m)
  • Wing area: 1,048 ft (97.4 m)
  • Empty weight: 36,500 lb (16,590 kg)
  • Loaded weight: 55,000 lb (25,000 kg)
  • Max takeoff weight: 65,000 lb (29,500 kg)
  • Powerplant: 4 x Pratt & Whitney R-1830 turbosupercharged radial engines, 1,200 hp (900 kW) each
  • Zero-lift drag coefficient: 0.0406
  • Drag area: 42.54 ft (3.95 m)
  • Aspect ratio: 11.55

Performance

  • Maximum speed: 290 mph (250 knots, 470 km/h)
  • Cruise speed: 215 mph (187 knots, 346 km/h)
  • Stall speed: 95 mph (83 knots, 153 km/h)
  • Combat radius: 2,100 mi (1,800 NM, 3,400 km)
  • Ferry range: 3,700 mi (3,200 NM, 6,000 km)
  • Service ceiling 28,000 ft (8,500 m)
  • Rate of climb: 1,025 ft/min (5.2 m/s)
  • Wing loading: 52.5 lb/ft (256 kg/m)
  • Power/mass: 0.0873 hp/lb (144 W/kg)
  • Lift-to-drag ratio: 12.9

Armament

  • Guns: 10 x .50 in (12.7 mm) M2 Browning machine guns
  • Bombs:
    • Short range (less than 400 mi): 8,000 lb (3,600 kg)
    • Long range (about 800 mi): 5,000 lb (2,300 kg)
    • Very long range (about 1,200 mi): 2,700 lb (1,200 kg)

End notes