Pre-WWII Air Corps Bomber Doctrine I

In January 1935 Major Wilson drafted the tactical school comment on a proposed Air Corps doctrine prepared by the General Staff’s War Plans Division. Wilson’s concepts about the proper use of air force were explicit: “The principal and all important mission of air power, when its equipment permits, is the attack of those vital objectives in a nation’s economic structure which will tend to paralyze that nation’s ability to wage war.” Wilson believed that such a decisive use of air power would “contribute directly to the attainment of the ultimate objective of war, namely, the disintegration of the hostile will to resist.” Wilson continued, stating matter-of-factly that in a “war between major powers, an air force phase, which may be decisive, will be initiated prior to the contact of ground armies.” Additionally, the air force plan, once decided on, must have “unwavering adherence” to be effective. Finally, in an ironic twist, the Tactical School also noted that the importance of aviation justified the diversion of ground troops to guard air bases.

Quite simply, the Tactical School proposed that air power by itself could be the decisive factor in war if its control was left to those who knew how to employ the weapon—air officers. Furthermore, the study admitted that this doctrine was offensive and was to be directed against modern industrial nations once a suitable airplane made the theories feasible. Bomber technology was driving the development of a doctrine to exploit its potential, regardless of whether this doctrine was appropriate to stated American defense policies, but two crucial elements were still missing. First, the vital objectives in a nation’s economic structure that could paralyze its ability to wage war had to be identified. Second, an airplane capable of executing the doctrine was needed.

Key elements in the industrial web were identified through research at the Tactical School. Captain R. M. Webster decided that New York City was a good example of a city “highly dependent upon the mechanisms of modern civilization.” Accordingly, he wrote to the commander of the 2d Corps Area at Governor’s Island, New York, asking for assistance. He noted that he was conducting research to determine the “sensitive points in that city to air attack” to evaluate “the probable effects induced by their destruction.” Webster specified that he was particularly interested in the relation of New York City to the national economic structure as well as the city’s water, food, electric power, illuminating gas, and transportation systems.

Major F. V. Hemenway, an officer assigned to Governor’s Island, responded that the data were available but could be viewed only at the headquarters due to their nature. If Webster could not visit, Hemenway suggested he write to a number of New York state agencies for assistance. Webster took the advice and began a letter-writing campaign that included the National Board of Fire Underwriters, the New York City Board of Water Supply, the Director of the Bureau of the Census, the Museum of Sciences and Industry, and the Consolidated Gas Company. Most of the addressees provided Webster with the information he requested, and he soon amassed an impressive amount of data. From such efforts the Tactical School determined the targets most vulnerable to bombardment attack.

Technology supporting the evolving doctrine was also forthcoming. In August 1935 the Douglas, Martin, and Boeing aircraft companies each sent bomber prototypes to Wright Field in Dayton, Ohio, to compete for the Air Corps multiengine bomber contract. The Martin entry was a larger version of the firm’s B-10, while the Douglas airplane was a derivative of its commercial DC-2 design. Each had two engines and were evolutions of existing aviation technology.

The Boeing entry, the four-engined model 299, was revolutionary. It had flown nonstop the 2,100 miles between the Boeing plant in Seattle, Washington, and Wright Field, at an impressive average speed of 232 miles per hour. The operational capabilities promised by the model 299 were impressive: a top speed of 251 miles per hour; a cruising range of 2,600 miles, with an increase to 3,150 miles feasible; a normal bomb load capacity of 2,500 pounds; and a service ceiling of 27,600 feet.

The Boeing airplane caused General Foulois, chief of the Air Corps, to rethink the entire Air Corps procurement program for fiscal year 1936. On October 1 Foulois requested that the approved requirements of 438 airplanes of all types be revised downward to a total of 333 so that 65 Boeing bombers could be purchased.

Within the month, however, the airplane procurement plan again had to be revised. On October 30 the Boeing prototype bomber crashed, not because of any defect in the airplane but because the crew had neglected to unlock the rudder and elevator controls during preflight checks. Unfortunately, the crash occurred before the necessary regulatory evaluations of the airplane had been completed, precluding “an award being made to the Boeing Aircraft Company under competitive conditions for 65 of these bombers.”

Still, Westover believed that the Boeing plane was a “remarkable aeronautical development” and that thirteen of the bombers should be procured “under Section 10 (k) of the Air Corps Act for experimental service test.” Westover went on to recommend that in addition to the thirteen Boeing planes, eighty Douglas prototypes be purchased if they proved superior to the Martin entry. Colonel William T. Carpenter, Supply Division, G-4, advised the chief of staff to approve Westover’s new Air Corps plan.

On November 21 the chief of staff approved the request, and thirteen Boeing airplanes were ordered. The contract for the Boeing bomber, designated the Y1B-17 pending service test, was closed on January 17, 1936. Delivery began the following January, and by August 1937 all thirteen of the B-17 bombers had been accepted by the Air Corps.

Over the next three years, the Air Corps asked for more B-17s and bombers of even greater range, but the War Department resisted. Its position stemmed from two considerations. First, the department believed that the twin-engined B-18 (the standardized Douglas prototype) was adequate for national defense purposes, particularly since substantially more B-18s than B-17s could be purchased with the limited budget.55 Second, the War Department argued that bombers with greater ranges than that of the B-17 were out of step with American policy, since they could “bomb points in Europe and South America and return without refueling.” Consequently, such an airplane was inappropriate “in the armament of a nation which has a National Policy of good will and a Military policy of protection, not aggression.”

The Air Corps arguments were articulated well by General Andrews. At a September 1936 conference concerning the continued funding of the Project D airplane, Andrews stated that the Army needed “airplanes of long endurance” to “stop hostile air expeditions at their sources,” to maintain continuous reconnaissance to guard against sea invasion, and to bomb enemy aircraft carriers at distances from national coasts that would prevent them from launching their aircraft. Andrews argued that the Air Corps should have the most advanced equipment available. Since “a future international situation may set up a need for planes of greater power,” the War Department authorized research and development of a generation of bombers beyond the B-17 but offered little more.

General Andrews undoubtedly envisioned roles for long-range bombers, including the B-17, beyond those he mentioned in the conference. The missions he discussed were those sanctioned for the GHQ Air Force by the October 1935 War Department training regulations—that is, air operations that were “beyond the sphere of influence of ground forces,” in the “immediate support of ground forces,” or involved “in coastal frontier defense and in other joint Army and Navy operations.”

Even in the unlikely event that Andrews wanted more bombers at least as capable as the B-17 to perform only the War Department–authorized missions, some air officers at the Tactical School believed strongly in the old adage “the best defense is a good offense.” In a 1936 lecture on the principles of war, Major Harold George blithely dismissed American military policies in the face of the new bomber technology:

I like to compare the strategy of an air force with the measures used by the Medical Department in ridding the Canal Zone of mosquitoes. That department did not put fly swatters in the hands of the population and then go back to its hospitals. Not by any means. The Medical Department went to the places where those mosquitoes lived and breeded and there they exterminated them,—not by defensive action but with offensive action.

This offensive doctrine called for an airplane of great range, whose “ultimate radius of action…is that which will enable us to strike the nerve centers of any potential enemies from our own territory.” The B-17 was a major step in this direction. Here, for the first time, was an airplane capable of transforming the bomber advocates’ theory into reality.

Aside from its range and bomb load, the B-17 had capabilities that seemingly made it virtually invincible. Its demonstrated speed of 250 miles per hour was faster than the standard Air Corps pursuit airplane, the P-26, whose maximum speed was 234 miles per hour.61 Increased speed also enabled bomber advocates to dismiss antiaircraft fire as a threat. The 1935 Bombardment text proclaimed confidently: “Higher speeds will also give the bombardment airplane a higher degree of immunity from antiaircraft fire than it already enjoys.” Furthermore, it appeared that bomber speed would only increase as bomber design advanced, further widening the gap between the bomber and pursuit aircraft. The reigning wisdom among American aviation engineers, particularly in the matériel division of the Air Corps, was that “increased aerodynamic efficiency could be achieved with increased size.” The apparent solution to increased speed, range, and carrying capacity was to design airplanes with larger airframes and powered by multiple engines of great horsepower.

In addition to the B-17’s impressive performance characteristics, it was the Air Corps’s first bomber large enough to mount guns larger than .30 caliber. The capability to carry heavier armament meant that the B-17 had a much greater chance of defending itself. Many Air Corps officers thus came to believe that when bombers were flown in tight formations the synergy of their massed weapons would create a wall of fire through which no pursuit plane could pass. For the bomber advocates, the B-17 settled the issue of the ascendancy of the bomber over the pursuit airplane. They were convinced that the “present and potential single engine pursuit planes” were “ineffective” against the new bomber since they were slower and had less range and weaker armament. Quite simply, the Air Corps was convinced the B-17 was an unstoppable weapon. Brigadier General Henry H. Arnold, commander of the 1st Wing, GHQ Air Force, asserted that “with the wide variety of targets available to long range bombardment, it is out of the question to expect that pursuit can be so placed as to intercept all air raids.”

The conviction that long-range bombers could not be deterred, reinforced by the technological breakthrough of the B-17, was the catalyst that made American air doctrine dogma. The invincibility of the bomber was a powerful assumption on a number of levels. First, if the United States could develop such a formidable bombardment capability, it had to be assumed that potential enemies could do so as well. Therefore, since their bombers would be invulnerable to defensive means, they could be stopped only by counter–air force operations. This mission, which required strategic long-range bombers in a defensive role, did not tie their procurement to the contentious coast defense. Second, the mission against an enemy’s air force, if presumed to be the most important role for aviation, gave the Air Corps additional arguments for autonomy. How could such a valuable weapon possibly be tied to the support of ground forces? The Air Corps understood clearly the implications of such arguments: “The United States must provide bombardment aviation at least the equal in numbers, range and speed performances, and striking power, to that of any other nation or possible coalition.”

From these crucial assumptions the Tactical School made the final refinements to Air Corps doctrine. The doctrine had two fundamental premises. First, “modern nations cannot wage war if their industries are destroyed.” Second, “aircraft can penetrate any known air defenses and destroy any known targets with bombs.” These premises led to the conclusion that “air warfare is…a method of destroying the enemy’s ability to wage war. It is primarily a means of striking a major blow toward winning a war, rather than a direct auxiliary to surface warfare.”

The conviction that the bomber was all important and all but unstoppable had a telling effect on how the Air Corps viewed other classes of aviation. By 1937, when the rout of the pursuit advocates was complete, their most vocal champion, Claire Chennault, retired. Forty years later General Laurence Kuter, a former bombardment instructor, recalled the victory of the bomber advocates: “We just overpowered Claire; we just whipped him.”

Kuter further explained that the bomber advocates defeated Chennault and the pursuit boosters by edging them out in a number of crucial areas, including “attention by the chief’s office, for appropriations, for personnel assignment, appropriations primarily. We got money for B-17s; he didn’t get anything.” Kuter also noted that Chennault was myopic about pursuit: “He wouldn’t talk about a fighter to accompany a B-17, a supporting defensive fighter, because that put the fighter in a secondary role.” Finally, Kuter noted the chasm between the competing camps in the Air Corps: “We wouldn’t talk about it [pursuit] either because that implied some of the limited funds might have to go to a supporting fighter of some sort. We didn’t believe we needed it in the first place, and where there was doubt, we believed that the limited amount of money was barely enough to get a bomber program started.”

The crucial assumption that enemy pursuit would be ineffective against American bombardment was repeated in the Air Corps doctrine about its own pursuit tactics. The 1939 Pursuit text noted that although the role of pursuit remained the attack of enemy bombers, the mission was questionable. Since pursuit had lost its speed advantage and had limited range, its attacks on heavily armed enemy bombardment formations “must be confined to harassing by long-range fire or by bombing if so equipped.”

The conviction that air power was potentially decisive also shaped the doctrine for support of the ground battle. The Tactical School rationalized that since air forces were so powerful the best service the Air Corps could provide to the ground commander was the defeat of enemy air power. Thus, the “neutralization of the hostile air attacking force” became the principal Air Corps contribution to the ground battle. Furthermore, the old contention that aviation was viewed by ground officers as “long-range artillery” was now used to the aviators’ advantage by asserting that “air attacks are not made against objectives within the effective range of friendly artillery, or against deployed troops, except in cases of great emergency.” Finally, Tactical School instructors emphasized that bombardment was simply too valuable to use in any type of ground support role.

Attack aviation doctrine was radically altered by this view that counter-air force operations were primary, since attack aviation had as its principal role “the attack of hostile ground forces…in close cooperation with ground forces in battle.” By 1935 targets for attack aviation were enemy air bases and parked airplanes; coast defense; antiaircraft defenses; and “the destruction, or the interruption of movement of personnel and materiel through the attack of factories, logistical establishments, lines of communication, and concentrated bodies of troops.”

The Tactical School’s marginalization of the ground support mission extended to the integration of tanks and airplanes into a combat team. In October 1938 Colonel John H. Pirie, acting commandant of the school, wrote to the chief of the Air Corps that he believed that airplanes, when compared with tanks, were fragile and susceptible to ground fire and that using them in a close support role jeopardized a valuable weapon system. Furthermore, air power was most effective when employed “beyond the local ground combat zone.” Therefore, using airplanes to “clear the path of the more rugged tank…clearly appears to be tactically unsound…except in the gravest emergency.”

The deteriorating European situation provided the impetus to expand the Air Corps into a force capable of executing the doctrines espoused at the Tactical School. When in September 1938 British Prime Minister Neville Chamberlain acceded to Adolf Hitler’s demands to dismember Czechoslovakia, George Fielding Elliot, a respected military commentator, suggested that Chamberlain had capitulated because of Germany’s immense advantage over England in air strength. Elliot concluded: “It is blackmail which rules Europe today, and nothing else: blackmail made possible only by the existence of air power.”

Joseph P. Kennedy, the American ambassador in London, shared Fielding’s opinions about the power of the Luftwaffe. On September 22 he informed the secretary of state of his recent conversation with Charles Lindbergh, who had just returned from a review of European air forces. Lindbergh’s opinions were alarming. He asserted that “Germany’s air strength is greater than all other European countries combined and that her margin of leadership is constantly being increased…. If she wishes to do so, Germany now has the means of destroying London, Paris, and Prague.” He further observed that only the United States could hope to compete with Germany in the aviation field.

On October 13 William C. Bullitt, the American ambassador to France, told President Roosevelt that Hitler had been able to dictate his terms at Munich because of his vastly superior air strength. He echoed Lindbergh’s conviction that only the American aviation industry could compete with Germany’s. Bullitt also told the president that the French believed that they and the British would have to rely on American production to counter the threat posed by the Luftwaffe.

Roosevelt soon settled on how America would respond to German military power. On November 14 he assembled key civilian and military advisers and sketched the outlines of a new national defense policy based on his belief that American defenses had to be bolstered in light of the situation in Europe. The country had to be “prepared to resist assault on the Western Hemisphere ‘from the North to the South Pole.’” The key to the plan, the president argued, was a massive expansion of American air power. Although he wanted an Army air corps of 20,000 planes and an annual production capacity of 24,000, he realized that Congress would not support such numbers and instead directed the War Department to develop a program based on 10,000 planes.

Roosevelt’s pronouncement produced mixed views in his military subordinates. General Arnold believed “that the Air Corps had achieved its Magna Carta.” He was fully receptive to the president’s conclusion that a strong air corps, not a large ground force, was the best way to deter aggression in the American hemisphere. Arnold also concluded that “the president had not only made permissible but had required the development of the long-range heavy bomber.” He left the White House with the seed of an idea for a balanced American air force branch planted firmly in his mind.