San Diego, California December 29, 1939

On this date in 1939 a prototype four-engine heavy bomber took off from San Diego’s Lind­berg Field on its maiden flight. The flight lasted 17 minutes. Designed by Consol­i­dated Air­craft, the proto­type was ini­ti­ally known in-house as Model 32. Besides its dis­tinc­tive twin tails and slab sides that allowed for capa­cious twin bomb bays, it was equipped with a tri­cycle under­car­riage for faster take­offs and landings and a thick, shoulder-mounted, low-drag patented “Davis” wing that increased the plane’s speed, range, and load capa­bil­ity over con­tem­po­rary bomber air­craft like the Boeing B‑17 Flying For­tress. Earlier in 1939 the U.S. Army Air Corps selected the Model 32 following a rigged design study only Consol­i­dated could win and in March ordered a single experi­mental XB‑24 bomber. Later that year the Army ordered 38 B‑24As, which had improved aero­dynamics for better per­for­mance. Only 29 were produced, with 20 being sold to the Royal Air Force as LB‑30Bs (see photo essay below).

More modern than the legendary Boeing family of four-engine “Forts,” Con­soli­dated’s B‑24D, the first model pro­duced on a large scale, entered U.S. mili­tary ser­vice in 1941 as a poten­tial replace­ment for the B‑17. Of course, it never came to that. Both air­planes were pro­ducts of 1930s aero­nau­tical engi­neers, but the ungainly “Flying Box­car,” as the B‑24 was nick­named, proved more rugged, had greater endur­ance, and out­did its Boeing com­pa­triot in speed and oper­a­tional range. Long-range B‑24s (meaning they could fly 1,540 miles with normal fuel and maximum internal bomb load of 12,800 lb) also carried upwards of two-thirds more ordi­nance by weight than long-range Flying For­tresses. Though both heavy bombers were main­stays of the U.S. stra­te­gic bombing cam­paign in Western Europe, the Liberator’s longer range proved use­ful in bombing oper­a­tions in the Asia-Pacific thea­ter, which grew to include the Japa­nese Home Islands. Very long-range (VLR) anti­sub­marine Libe­ra­tors played an instru­mental role in shrinking the mid-Atlan­tic “gap,” con­sidered by U‑boat cap­tains to be safe from land-based attack air­craft, and helping win the Battle of the Atlantic. With a maxi­mum fuel load of 2,500 gallons, a Libe­ra­tor could spend 3 hours patrol­ling more than 1,100 miles from base, an hour more and almost twice the dis­tance from base com­pared with Lock­heed Hudsons and British Welling­tons, Arm­strong Whitworth Whitleys, and Sunderlands.

A total of 19,203 B‑24 variants were manu­factured at five U. S. facil­i­ties, making the Libe­ra­tor the world’s most-pro­duced bomber, heavy bomber, and multi-engine air­craft in U.S. mili­tary history. (The RAF con­ferred the name “Libe­ra­tor” on the B‑24, and the name was embraced by the U.S. Army Air Forces.) Besides Conso­li­dated Air­craft’s Cali­for­nia plant, B‑24 Libe­ra­tors were built by Conso­li­dated in Fort Worth, Texas; Douglas Air­craft (now Boeing) in Tulsa, Okla­homa; North Amer­i­can Avia­tion (now part of Boeing) in Dallas, Texas; and Ford Motor Com­pany at Willow Run near Ypsi­lanti, Michi­gan. More than 42,000 workers at the 3.5 mil­lion-square-foot/­325,161 square-meter Ford plant, believed to be the largest fac­tory under one roof, built just under half the world’s Libe­ra­tors: 6,792 com­plete planes and 1,893 knock-down kits. At peak pro­duc­tion, the Ford assem­bly line, over one mile long, churned out one B‑24 every 51 to 59 minutes, a rate so high that the “arsenal of demo­cracy” itself was unable to con­sume all the out­put, an embar­rass­ment of riches. Besides the United States, major B‑24 con­su­mers were Great Britain, Canada, Aus­tral­ia, and South Africa. Liber­a­tors were recorded as having dropped over 630,000 tons of bombs and downing several thousand enemy aircraft with their guns.

U.S. and British Heavy Bombers During World War II

Rare color photo of a preproduction prototype LB-30A wearing British rondelle Boeing B-17

Left: Rare color photo of a preproduction B‑24 proto­type wearing British rondelle. Six were sold to the UK directly and desig­nated LB‑30A (LB signi­fying Land Bomber). Far more B‑24 Lib­er­ators were pro­duced and were used more exten­sively than Boeing B‑17 Flying For­tresses, both in stra­te­gic bombing cam­paigns, on long-range anti­sub­marine patrols, and as trans­ports (C‑87s). In fact, only in the U.S. Eighth Air Force were B‑17s pre­dom­i­nant in num­ber. So many his­to­rians have focused on the war in Europe, devoting much paper and ink to the four-engine Boeing bomber, that the B‑17 is often thought to be the only Amer­i­can long-range bomber of the war until the much larger Boeing B‑29 Super­for­tress was put in service in May 1944. Iron­i­cally, the more modern B‑24 was designed to replace the B‑17, with vastly improved per­for­mance owing to a shoulder-mounted, low-drag, aero­dyna­mi­cally shaped wing (Davis wing) that afforded higher speeds, greater fuel effi­ciency and explo­sive pay­loads, and supe­rior oper­a­tional range. Con­versely, the B‑17’s large wing area (25 per­cent larger) made the plane easier to fly and at higher alti­tudes than the B‑24, but it pro­duced con­sid­er­able drag, limiting its speed and severely reducing its operational range. Also, the B‑24 had a higher accident rate than the B‑17, giving it another nickname: “Widow Maker.”

Right: By the time the U.S. entered World War II in December 1941 the Boeing B‑17 Flying For­tress was out­dated based as it was on 1920s-early 1930s tech­no­logy. Some 12,731 B‑17s were pro­duced between 1936 and 1945. First flown in com­bat by the Royal Air Force over Europe, the British found the B‑17’s per­for­mance dis­mal and pre­ferred flying the Con­sol­i­dated B‑24/LB‑30 Liber­ator. B‑17s flew with the U.S., British, and Soviet air forces. The German Luft­waffe even flew a dozen captured ones. Flying For­tresses were armed with thir­teen .50 cali­ber (12.7mm) M2 Browning machine guns in eight posi­tions. Depending on the dis­tance of the mission, a B‑17 could carry between 4,000 and 8,000 lb of bombs. (Loaded with a 6,000‑lb bombload, it had a range of 2,000 miles.) More bombs were dropped by B‑17s than by any other U.S. air­craft in World War II. Of the 1.5 mil­lion metric tons of bombs dropped on Nazi Germany and its occupied terri­tories by U.S. aircraft, 640,000 tons were dropped from B‑17s. During the course of the war more than 5,000 B‑17s were shot down by German fighter planes or flak batteries.

 RAF Avro Lancasters, September 29, 1942Halifax Mk II of RAF No. 35 Squadron

Left: Three RAF Avro Lancaster B.Is based at Wadding­ton, Lincoln­shire, fly above the clouds, Septem­ber 29, 1942. Intro­duced into ser­vice in Febru­ary 1942, 7,377 of these four-engine “Lancs” were built. They became the main heavy bomber used by the RAF as well as the most famous and suc­cess­ful of the war’s night bombers in con­trast to the USAAF heavy bombers that were used mostly in day­light raids over occu­pied Europe. On the night May 16, 1943, a British squad­ron of 19 modi­fied Avro Lan­caster bombers (Mk.III), each with a 9,250‑lb pay­load of one exter­nally mounted, specially designed “bounc­ing bomb” (actually a revolving depth charge), flew toward three dams on the Moehne and Eder rivers in the Germany’s Ruhr Valley in the state of North Rhine-West­phalia. In a spec­tac­ular feat of pre­ci­sion bombing, the “dam­busters” in Oper­a­tion Chas­tise arguably per­formed the most auda­cious bombing raid of the Euro­pean war, breaching two of three tar­geted dams. The Moehne dam alone spilled around 330 mil­lion tons of water into the west­ern Ruhr region, devas­tating fac­tories, muni­tion plants, homes, mines, and farm­land for miles around. Bodies of at least 1,579 vic­tims were found along the Moehne and Ruhr rivers, 70 in the Eder Valley, with hun­dreds of people gone missing. The RAF lost 8 Lan­casters and 53 crewmembers in the Chastise raid.

Right: Squadron No. 35 was the first RAF squa­dron to use the Hand­ley Page Hali­fax pictured above. The Hali­fax entered military service in Novem­ber 1940. Squa­dron No. 35 carried out the first Hali­fax raid on March 10/11, 1941, over Le Havre, France. Both the Avro Lan­caster (left frame) and the Hali­fax emerged as capa­ble four-engine stra­te­gic bombers. Air Chief Marshal Sir Arthur Harris, since Febru­ary 1942 head of RAF Bomber Com­mand, depre­cated the Hali­fax for its smaller pay­load, sharing as it did the same speci­fi­ca­tion as the con­tem­po­rary twin-engine Avro Man­chester. Hali­fax’s stable mate Lan­caster had the dis­tinc­tion of carrying the 22,000 lb earth­quake bomb called Grand Slam used by Bomber Command against hardened German targets towards the end of World War II. During their war­time service Hali­faxes flew a total of 82,773 oper­a­tions and dropped 224,207 tons of bombs, while 1,833 air­craft were lost. The Hali­fax was flown in large num­bers by other Allied and Com­mon­wealth air forces such as Canada’s, Australia’s, the Free French, and Poland’s.

The Story of Ford’s Willow Run and the Building of the B‑24 Bomber