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The Boeing B-17 Flying Forteess

Mission Accomplished: The Story of the Flying Fortress (1942) Chronicles one of the early (autumn 1942) bombing runs of B-17s over Europe. Internet Archive

Initially designed for a purely defensive role-the protection of the American coastline from foreign surface fleets-the Boeing B-17 shared the honours with the Consolidated Liberator of being the principal heavy bomber of the U.S.A.A.F. in World War II. The prototype, the Model 299, was designed to an Army Air Corps specification of 1934, and it was the aircraft's defensive role, and not its seemingly formidable defensive armament concentrated in five fuselage stations, that suggested the name `Flying Fortress'. The 299 was powered by four 750 h.p. Pratt and Whitney Hornet engines, and in August 1935-only a month after its roll-out-it flew to Wright Field, Dayton (Ohio), averaging 232 m.p.h., a record breaking performance for those days. Thirteen service test models were subsequently built, and the last one, delivered in January 1939, was the first to be specially modified for high-altitude bombing and fitted with turbo-superchargers.

First production model was the B-17B, this being followed in 1940 by the B-17C, which featured a long bath-shaped ventral gun position, and had sliding windows over the waist gun positions instead of blisters. Twenty B-17Cs were bought by the British Purchasing Commission and the first of these Fortress's, as they became known in R.A.F. service, were ferried across the Atlantic in the spring of 1941. The first aircraft to arrive was AN521.

Behind the strategy that governed the American air war in Europe during World War II lay events and ideas that dated back to World War I and the 1920s. The first strategic bombing raid in 1915 deployed not airplanes but German Zeppelins, rigid airships that dumped ordnance on the east coast of Great Britain. Two years later Germany's Gotha bomber, a machine capable of a round trip from Belgian bases, struck at Folkestone, a port through which British soldiers embarked for the front. This raid killed 300 people, including 115 soldiers. The bomber had proven itself as a weapon against a military target.

A few weeks later, 14 Gothas attacked London in the first fixed-wing assault upon civilians and their institutions. The dead and wounded totaled 600, and the raid wrought consternation among the public and the government. The British hastily summoned fighter units to gird the cities. To counter the defensive cordon, the Gothas flew night missions. With primitive navigational tools and no bombsights, the raiders drizzled explosives without any pretense of hitting military or industrial targets. Theoreticians of war now had a new factor to enter into equations: the terror of massive strikes upon workers producing the stuff of war.

Brigadeer General Billy Mitchell, who had only earned his wings in 1916, commanded the air force for General John J. Pershing and his American Expeditionary Force in France. Mitchell met Maj. Gen. Hugh M. Trenchard, commander of the Royal Flying Corps, who quickly persuaded the American that the "airplane is an offensive and not a defensive weapon." Mitchell grasped the possibilities of taking the war behind the lines and plotted a huge raid that would blast German military and industrial targets in the autumn of 1918. A correspondent for the Associated Press wrote, "His navy of the air is to be expanded until no part of Germany is safe from the rain of bombs.... The work of the independent force is bombing munitions works, factories, cities and other important centers behind the German lines.... Eventually Berlin will know what an air raid means, and the whole great project is a direct answer to the German air attacks on helpless and unfortified British, French and Belgian cities."

World War I ended before Mitchell could demonstrate what his "navy of the air" might achieve, but he continued to expound his ideas. While accepting the need for control of the skies through destruction of the enemy air forces, he said, "It may be ... the best strategy to damage and destroy property, and to kill and disable an enemy's forces and resources at points far removed from the field of battle of either armies or navies." Implicitly, Mitchell accepted war on civilians.

In 1921 and 1923, Mitchell demonstrated that bombers could sink some anchored warships. The experiments confirmed that aircraft could destroy substantial stationary targets, but admirals scoffed that vessels under way could easily avoid the attacks. The Army dismissed the show as irrelevant for its vision of warfare, which was to slugg it out with hostiles while capturing territory.

While Mitchell and Trenchard promulgated their ideas of aerial offensives, a contemporary Italian, General Giulio Douhet, preached that modern war involved the entire society, including "the soldier carrying his rifle, the woman loading shells in a factory, the farmer growing his wheat, the scientists experimenting in the laboratory." Douhet spoke not only of smashing wartime production but argued, "How could a country go on living and working, oppressed by the nightmare of imminent destruction." He conceded that such a war without mercy eliminated considerations of morality.

Americans partially bought into the Douhet's theories. They buried the idea of indiscriminate raids that slaughtered nonmilitary people and emphasized hitting industrial production, transportation facilities, and military centers. Promoters of strategic bombing hypothesized that by destroying the goods of war and the will of the people to resist, conflicts could be shortened and the wholesale carnage of the World War I battlefield avoided.

Mitchell's outspoken demands for an independent air force ended his career, but acolytes like Henry "Hap" Arnold, Carl Spaatz, and Ira Eaker retained positions in the military hierarchy. They successfully promulgated the doctrine of strategic bombing, accurate targeting of enemy installations and facilities. Toward that end, in 1933 the War Department approved a prospectus for a plane capable of traveling at speeds in excess of 200 miles per hour and with a range of more than 2,000 miles. The new bomber could be used to defend either coast, but if deployed overseas it would require bases in England or sites like the Philippine Islands. Boeing produced the first model of the Boeing B-17 Flying Fortress, which roared through the sky at 232 mph during a 2,100 mile trip from Seattle to Dayton. The advocates of air power were delighted, but unfortunately the prototype crashed and burned on a test flight. Instead of ordering 65, the War Department scaled back to a mere 13.

To carry out daylight precision bombing the Army adopted a tool ordered and then discarded by the Navy as unsuitable for divebombers: the Norden bombsight. In the crucial seconds over an objective, a bombardier manipulated the device to guide the plane as he lined up the target and then released the explosives.

Douhet also taught his disciples that heavily armed bombers in mass formations could operate by day against fighter defenses. The publicity on Boeing's creation hailed the new airplane as a "Flying Fortress," but it was hardly as impregnable as the name indicated. The first B-17s lacked armor plate to protect the crew, carried only five machine guns, and made no provision for a tail gunner. The B-17 faithful believed that was sufficient since, in their minds, the aircraft could attain altitudes beyond reach of interceptors. In the late 1930s, a hot shot fighter pilot, Lieutenant John Alison, confounded the assurance of promoters of the early B-17 when he convincingly demonstrated he could push his fighter close enough to the weaponless rear of a Flying Fortress and shoot it down. His feat, however, did not immediately persuade the bomber command to install a tail gun. Nobody in the Air Corps was going to listen to a pursuit pilot, a second lieutenant who claimed, "I can shoot those things down very easily."

The conviction that strategic bombers could operate unmolested by enemy aircraft influenced the development of U.S. fighters. Escorts to protect the big planes would be unnecessary, and the design for a fighter focused upon a machine that would protect the ground forces. Not until the Battle of Britain in 1940 and the appearance of the Messerschmitt Me-109 did the American experts realize that the speed and altitude of an enemy fighter challenged their assumptions about the invulnerability of the B-17. The standard American fighter, the Curtiss P-40 Tomahawk - a good gun platform, while speedy in a dive - had a limited ceiling and rate of climb. It would not be deployed in the European Theater.

Desire for an interceptor with longer range and performance higher in the sky had belatedly resulted in the twin-engine Lockheed P38 Lightning, and aeronautical engineers returned to their drawing boards to blueprint what would become the Republic P-47 Thunderbolt and the North American P-51 Mustang. At the same time manufacturers modified the big bombers, now including the Consolidated B-24 Liberator, which had slightly more range and bomb weight capacity than the B-17, adding better means to defend themselves: up to 12 .50-caliber machine guns, a tail gunner, and armor for the crew. When the enemy changed tactics during World War II and began head-on attacks, a chin turret would be added to give greater firepower forward.

From the start of World War II, the British intended to follow Trenchard's maxims on carrying the war to the industrial centers and the population of the foe. In May 1940, when the Royal Air Force attempted daylight strategic raids by its fleet of bombers, German ack-ack and interceptors killed more flyers than the enemy lost on the ground. B-17s purchased from the United States carried out a few daylight missions with dismal results and curdled RAF enthusiasm for the Flying Fortress. American analysts noted that the Brits insisted on operating above 30,000 feet, which overloaded the oxygen systems, froze weapons, and reduced airspeed, making the planes vulnerable to the Me-109s. The RAF B-17 missions relied on an inferior bombsight, and the maximum number of aircraft in formation was a mere four. The British, using their own bombers, switched to nighttime assaults, on industrial areas. They made no pretense of discriminating between residential neighborhoods and factories.

The British tried to convince the Air Corps that it too should operate after dark. That would have negated the entire basis for the designs of the B-17 and B-24 and wasted the hundreds of hours training of bombardiers with the Norden device. Faith in daylight precision bombing thus remained intact as the United States entered World War II. There was no disagreement with the British on the purposes and potentials of air power. Maj. Gen. Ira Eaker, who headed the American bomber command in 1942, said, "After two months spent in understanding British Bomber Command, it is still believed than the original allout air plan for the destruction of the German war effort by air action alone was feasible and sound and more economical than any other method available." He did agree that since the resources then available were limited, a ground effort might be required.

The development of the four-engine bomber was such a turning point in the course of air power - of world power, as it worked out-that. The Boeing Flying Fortress, the B-17, was the first of the four-engine bomber type. It had only one predecessor of equal importance in air history. That was the first "military aircraft" of the Wright brothers in which Lieutenant Tom Selfridge was killed in 1908. The patterns were sadly alike. On its first official flight at Dayton, Ohio, on October 30, 1935, the first B-i7 crashed before the eyes of the high Air Corps officials who had come to decide upon it, and killed Major P. P. Hill, one of the finest test pilots in the Air Corps, killed the Boeing test pilot, injured four others of its crew, and looked like a flop. Maintenance people had failed to familiarize themselves sufficiently with new features; the horizontal tail surfaces were not properly unlocked, and almost as soon as it was airborne the great new bomber was in flames on the runway.

However, as with the first Wright plane, the specifications and the preliminary performance of the first B-17 had been too impressive for this tragic accident to wipe the Flying Fortress out. The 750 h.p. engines, demonstrated by Major Hill on earlier flights, and the size of the craft combined with its featherlike maneuverability, had astonished seasoned observers. The introduction of a co-pilot's seat - it was not thought of then primarily in terms of the eventual teamwork between two pilots, but had been installed because the implied range of this airplane suggested that a single pilot would not fly it all the time-showed a new conception of air power. "With all those guns, it looks like a fort that can fly," somebody said, and the name stuck, though the early armament was nothing compared to the guns put on it later.

Despite the disaster, further trials were indicated. It wasn't altogether simple. Westover had to go to bat, and he did, standing up before the criticism and alerting the lower echelons of the Air Corps on what could be expected from that criticism with the same kind of letters a commander might send down in wartime. The upshot was that thirteen more B-17's were ordered, and as already told, the first two Flying Fortresses actually to be accepted by the Air Corps arrived at Langley Field almost at the same time I arrived in Washington.

From then on, the B-17 was the focus of our air planning, or rather of the Air Corps' fight to get an air plan - some kind of genuine air program - accepted by the Army. "Precision bombardment," of course, was not new. I've already told something of our pioneering with bombardment on the West Coast, where my 7th and 19th Bomb Groups had been entrusted with the first Martin B-10's, and the first Norden bombsights. The tough part of aircraft development and securing an air program is to make Congress, the War Department, and the public realize that it is impossible to get a program that means anything unless it covers a period of not less than five years. Any program covering a shorter period is of little value. Normally, it takes five years from the time the designer has an idea until the plane is delivered to the combatants. The funds must cover the entire period or there is no continuity of development or procurement. For years the Army - and the Army Air Forces while a part of it - was hamstrung in its procurement programs by that governmental shortsightedness.

Great strides had been made in the East in recent years by Major Hugh Knerr, despite the fact that neither the topography of the eastern states as regards bombing ranges, nor the equipment given him had been as good as ours. Knerr commanded the 2nd Bomb Group at Langley Field, and that unit received the first B-17's.

Our horizons had been strictly limited prior to the arrival of the four-engine bomber. Range, fire power, bombload - in all respects, our bombers before this had fallen short of the thing we all preached and hoped for, the "other" independent function of air power in which we had so long believed, which Billy Mitchell had described as if it were already there.

True, the "strategic" function of this new plane, as laid down by the over-all plans for national defense at that time, was still only a "tactical" employment. The B-17, too, was intended to sink enemy ships approaching our shores. It was some time later that General Frank M. Andrews still had to argue in the struggle for its procurement that the B-17 was "especially useful for coastal patrol." But even at that, the interception would be hundreds of miles farther at sea and formations of Flying Fortresses could cover in an hour more distance than a fast enemy ship could be expected to cover in a night. (Realizing this soon, the Navy raised hell like a country gentleman finding poachers on his property.)

The four-engine bomber was the first positive answer to the need arising from the United States' modification of the Douhet theories, which we had been teaching as an abstract science at the Air Corps Tactical School for several years. Ever since Versailles, Germany had been considered the next enemy by most strategists, including Billy Mitchell, whose notion, however, that Japan would come flying to attack us "some fine Sunday morning" was less heeded.

The large bomber was the center of the "bomber controversy." If one thinks of the state of the world in 1936, the year the Spanish Civil War began, the year after Mussolini invaded Ethiopia, the year immediately before Japan went into China proper, the year in which Hitler's remilitarization of the Rhineland took place, it would seem that the time was overdue for some kind of clear-cut thinking about American air power to have started in the War Department. It hadn't. And in that connection, this is a good place to note one or two facts that are sometimes oversimplified.

Despite popular legend, we could not have had any real air power much sooner than we got it. By that, I mean the genuine nucleus of air power, able to expand quickly enough to meet whatever demands were made upon it, that was foreshadowed technically by the appearance of the four-engine bomber, and which was to obtain its real Magna Carta in the office of President Roosevelt on September 28, 1938.

Unbelieving men in high places, battleship admirals, generals, and others who seized on Billy Mitchell's sins to eliminate him, didn't eliminate air power at all, nor retard it half so much as has been said. Actually, they didn't even eliminate Billy. They broke his heart, but from the day of his trial, public opinion was mostly on his side. The point is, that kind of public opinion couldn't help air power then in any conclusive degree, and no other kind of public opinion was ready.

In the United States the growth of air power had been thrown out of balance by a national policy based on the belief that weapons would be needed only to fight a defensive war against an invader. In such an attack against the United States proper, the Navy would fill its traditional role as the first line of defense, and land-based bombers would provide support by flying out, to sea and helping to sink the invader. Air Corps doctrine, based on offensive strategic bombing rather than continental defense, ran opposite. to this. But using national policy to justify the building of bombers, Air Corps planners concentrated on the development of a long-range bomber that could, among other things, intercept a hostile fleet far offshore. In the early 1930's this mission was entrusted to twin-engine planes like the Boeing B-9 and the Martin B-10. The B-10, with its enclosed cockpit, gun turrets, and retractable landing gear, was almost as fast as the best pursuit planes, and helped foster faith in the bomber.

Unfortunately, as a result, fighter plane design and production lagged in the prewar days. A few fighter enthusiasts like Chennault protested, vigorously but in vain. The Lockheed P-38, Bell P-39, and Curtiss P-40, designed in 1936 and 1937, were not ready when war broke out in Europe. At that point - September, 1939 - the Air Corps had only obsolescent Curtiss P-36's - and no night fighters at all.

But it did have the most powerful bomber in the world as a result of the vision and persistence of men like General Foulois. In July, 1935, the 18-17, a revolutionary four-engine long-range bomber, designed by Boeing, had been test-flown. In August it made a nonstop flight of 2,100 miles at an average speed of 232 miles per hour, which put it in a class by itself. Even before this, the Air Corps had asked for a bomber with a range of 5,000 miles, capable of flying to Hawaii, Alaska, or the Canal Zone without having to stop en route. This had resulted in the XB-15, an airplane that proved too large for any power plants then in existence. It was not put into mass production, but it was the direct ancestor of the B-29.

Interservice rivalry raised its head in 1938, when the Air Corps, demonstrating its range at halting an enemy offshore, sent a flight of B-17's to "intercept" the Italian liner Rex 725 miles at sea. The Navy viewed it as an invasion of an area intrusted to itself as guardian of the sea approaches, and the Air Corps shortly found its combat range restricted to one hundred miles off the coast. In addition it was instructed to limit itself to the number of B-17's completed or on order. The ruling was handed down, incredibly, on the eve of Munich.

Consolidated B-24 Liberator Consolidated's B-24 Liberator was one of the most costly and complicated aircraft produced by the US during WWII. It was produced in greater numbers than any other US bomber. 19,000 were built and served all over the globe as a bomber, transport, and long-range anti-submarine aircraft. This is a detailed examination of the design, development and use of the B-24 - the backbone of the USAAF bombing offensive during WWII. Extensively illustrated with over 200 archive photographs. Exceptional!

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