A Concise History of the U.S. Air Force/Interwar Doctrine, Organization, and Technology

190105A Concise History of the U.S. Air Force — Interwar Doctrine, Organization, and TechnologyStephen L. McFarland

Interwar Doctrine, Organization, and Technology

The scale of destruction and bloodshed in World War I was truly shocking. No one could have imagined 10 million dead and 21 million wounded soldiers or 9 million dead civilians. A generation had been slaughtered in the trenches, the events witnessed by 2 million American servicemen who went home from "over there," convinced that such a war should never be fought again. In its aftermath, diplomats pursued collective security through the League of Nations; the Kellogg-Briand Pact renouncing war as an instrument of national policy; the Locarno Pact recognizing the inviolability of European borders; and the Washington, London, and Geneva disarmament treaties and talks. In Germany airmen sought to restore mobility to the battlefield, joining aircraft and tanks to create blitzkrieg warfare. In America airmen strove for the coup de grace―strategic bombing directly against the vital centers of a nation's war-making capability.

American airmen came back from France with a unique perspective on modern war. Josiah Rowe, of the 147th Aero Squadron, wrote of the World War I battlefield as "a barren waste, broken only by shell holes, trenches and barbed wire, with not one living thing in sight." He was "glad to get away from such gruesome scenes" by climbing into the sky in his airplane. Billy Mitchell wrote that the Allies could cross the front lines "in a few minutes" in their aircraft, whereas "the armies were locked in the struggle, immovable, powerless to advance, for three years.... It looked as though the war would go on indefinitely until either the airplanes brought [it to an end] or the contending nations dropped from sheer exhaustion."

American airmen knew that aircraft lacked the range, speed, and reliability for strategic bombing, but they had faith that technology could overcome any restrictions. They also knew the importance of concentrating on basic objectives such as winning air superiority or interdicting the front, both of which, they believed, required an independent air force. They had caught tantalizing glimpses of what strategic bombing could do to an enemy's industrial centers. They saw the effectiveness of offense and the futility of defense against a determined aerial assault.

For these and other servicemen, aircraft seemed the answer to the slaughter of trench warfare. German airmen soon envisioned air power as mobile artillery accompanying fast-moving armored units (blitzkrieg warfare). American airmen, however, saw air power as an independent strategic force that could bring an enemy nation to its knees. Throughout history, an attacking army fought its way through a defending army to get to its enemy's vital centers. Strategic bombers would fly over the army to strike at the enemy's heart. Air leaders such as Billy Mitchell believed that with aircraft future wars would be shorter and less bloody.

During World War I America's air force had not coalesced. Afterwards it had to be built in an atmosphere of antiwar fervor and congressional stinginess. In addition, the U.S. Army and U.S. Navy, viewing the air force as their auxiliary arms and a supporting weapon, placed obstacles in the way of its further development. The President's Aircraft Board, better known as the Morrow Board for its chairman, the banker Dwight Morrow, called by President Calvin Coolidge in 1925 to evaluate the Air Service's call for independence, reinforced this view: "The next war may well start in the air but in all probability will wind up, as the last war did, in the mud." Evolving technology and irrepressible flyers, however, drove the Air Service in a different direction.

No one in the Air Service was particularly keen on flying close air support in trench warfare. Most airmen thought it unglamorous, marginally effective, and dangerous. What then could air power do, especially with advanced technology? The War Department General Staff already knew what it wanted from its airmen—close air support, reconnaissance, interdiction, and air superiority over the battlefield. The Dickman Board, named for its chairman, Major General Joseph Dickman, appointed in 1919 by General Pershing to evaluate the lessons of the war, concluded: "Nothing so far brought out in the war shows that aerial activities can be carried on, independently of ground forces, to such an extent as to affect materially the conduct of the war as a whole."

The Air Service could hardly contradict this judgment. Its heavy bomber at the time was the French-built Breguet. A veteran of the Great War with a range of 300 miles and a top speed of 100 miles per hour, it could only carry a 500-pound bomb load. In the postwar demobilization, by 1920 the Air Service was reduced to fewer than 2,200 officers and 8,500 enlisted men. To formulate basic doctrine for the fledgling air force and train officers, Air Service Chief Major General Charles Menoher established the Air Service Tactical School at Langley Field in Virginia, later to become the Air Corps Tactical School at Maxwell Field in Alabama. He made Brooks and Kelly Fields in Texas responsible for flight training and the Engineering Division at McCook Field in Ohio, later to become the Materiel Division at nearby Wright Field, responsible for flight technology. Congress provided the Air Service a measure of independence, changing it from an auxiliary force to an offensive force equal to the artillery and infantry, by creating the U.S. Army Air Corps on July 2, 1926.

Other aerial pioneers sought to test the versatility of aircraft through aerial exploration and discovery in a succession of record-setting flights. In 1921 Lieutenant John Macready climbed to 35,409 feet, higher than anyone before. In 1923 Macready and Lieutenant Oakley Kelly flew a Fokker T-2 nonstop across the width of the United States. In 1924 several Air Service crews led by Major Frederick Martin took 175 days to fly around the world. In 1925 Lieutenants Jimmy Doolittle and Cy Bettis won the Pulitzer and Schneider Cup speed races for the Air Service. Major Carl Spatz (later spelled Spaatz), Captain Ira Eaker, Lieutenant Elwood Quesada, and Sergeant Roy Hooe flew the Fokker tri-motor Question Mark to a record duration of 150 hours in 1929, displaying the great promise of inflight refueling. Doolittle and Lieutenant Albert Hegenberger achieved what the New York Times called the "greatest single step forward in [aerial] safety"―a series of blind flights from 1929 to 1932 that opened the night and clouded skies to flying. Only the Air Corps' assignment to deliver air mail in the first half of 1934, called "legalized murder" by Eddie Rickenbacker because of the 12 lives it claimed, detracted from the image that these aerial pioneers were helping to create.

Record-breaking military flights, alongside trailblazing civilian achievements by Charles Lindbergh and Amelia Earhart, represented the public side of a revolution in aviation technology. The staff at the Engineering Division, and later the Materiel Division, worked with American industry and the National Advisory Committee for Aeronautics (predecessor of the National Air and Space Administration) to develop essential technologies such as sodium-cooled engine valves, high octane gasoline, tetraethyl lead knock suppressants, stressed duraluminum aircraft structures, cantilevered wings, superchargers, turbosuperchargers, retractable landing gear, engine cowlings, radial engines, variable pitch constant speed propellers, and automatic pilots. The two-engine Keystone bomber of the 1920s, a biplane constructed of steel tubes and wires and fabric surfaces, with an open cockpit and fixed landing gear, could fly 98 miles per hour for 350 miles with one ton of bombs. A decade later Boeing's four-engine B-17 bomber could fly nearly 300 miles per hour for 800 miles with over two tons of bombs.

How would America's military aviators use this technology in war? The Army General Staff wanted to employ tactical air power "in


The Air Corps Tactical School at Maxwell Field in Alabama. Air officer training was first established in 1922 at Langley Field in Virginia under the Air Service Field Officers School, later redesignated the Air Service Tactical School.
direct or indirect support of other components of the Nation's armed forces." It believed the primary target was the adversary's army. The most vocal opponent of this view was Assistant Chief of the Air Service, Brigadier General Billy Mitchell, who saw in strategic bombing the proper use of air power. Close air support and interdiction, he asserted, only perpetuated trench warfare and the horrors of World-War I-like slaughter. He argued for a force that could strike directly at an enemy's vitals, "centers of production of all kinds, means of transportation, agricultural areas, ports and shipping," forcing "a decision before the ground troops or sea forces could join in battle."

Mitchell's actions created opponents as well as adherents. A series of highly publicized ship-bombing tests begun in 1921 overshadowed the ideas he had espoused in books such as Winged Defense: The Development and Possibilities of Modern Air Power―Economic and Military. Air Service bombers sank several unmanned, anchored ships, including battleships. Mitchell's apparent success, despite poor bombing accuracy, diverted both the public's and the Congress's attention from more critical aerial achievements and issues of the period. Mitchell's troubles with Army and Navy leaders eventually led to his court martial after he spoke intemperately about the crash of the airship Shenandoah in 1925. (He blamed the loss on "incompetency, criminal negligence, and almost treasonable administration.") President Coolidge, famous for his reticence and nicknamed "Silent Cal," expressed a widely-held view when he contended, "General Mitchell [has] talked more in the last three months than I [have] in my whole life."

Behind such scenes, Chief of the Air Corps Major General James Fechet urged his officers in 1928 to look beyond the battlefield, beyond close air support, and find a way for the Air Corps to win a war independently. He imposed only three limitations: First, the Air Corps had to get the most for any money available. Second, civilians could not be targets of aerial attack. Secretary of War Newton Baker had ruled earlier that doing so "constituted an abandonment of the time-honored practice among civilized people of restricting bombardment to fortified places or to places from which the civilian population had an opportunity to be removed." Americans would not undertake terror raids, he said, "on the most elemental ethical and humanitarian grounds." Third, anything the Air Corps did would have to solve or avoid the evils of trench warfare.

One officer who answered Fechet's challenge was Lieutenant Kenneth Walker. Conventional wisdom taught that while airmen achieved high accuracy when they bombed from high altitudes, they exposed themselves to deadly ground fire. Walker showed that daylight high-altitude

Interwar Air Service Pioneers

Top to bottom: Suited for extreme cold, Lieutenant John Macready with the Packard LePere aircraft in which he set the American altitude record of 34,508 feet in 1921; Sergeant Roy Hooe, Lieutenant Harry Halverson, Captain Ira Eaker, Major Carl Spatz (later spelled Spaatz), and Lieutenant Elwood Quesada after their record-setting endurance flight in the Fokker Trimotor Question Mark in 1929; the Question Mark being refueled on its famous flight; Lieutenant Jimmy Doolittle in the Consolidated NY-2 he piloted during blind flying tests in 1929. The enclosing hood is folded around the cockpit.
Interwar Aircraft
In amazing technological leaps, interwar military aircraft evolved significantly from, top to bottom, biplanes such as the Keystone B-4 bomber and Boeing P-12 fighter, to some of the first all-metal American monoplanes such as the Boeing P-26 fighter and the Martin B-10 bomber.
precision bombing was superior to low-altitude bombing and provided greater survivability, explosive force, and, ironically, accuracy. (Bombs released at low altitudes tumbled and ricocheted when they hit the ground.) He wrote, "Bombardment missions are carried out at high altitudes, to reduce the possibilities of interception by hostile pursuit and the effectiveness of anti-aircraft gun fire and to increase the explosive effect of the bombs." The keys to attaining accuracy from high altitudes were Carl Norden's new M-series bombsights, designed under Navy contract, but destined to equip Air Corps bombers beginning in 1933.

At Maxwell Field in Montgomery, Alabama, Major Donald Wilson and the faculty of the Air Corps Tactical School proposed in the early 1930s to destroy an enemy's ability to resist by bombing what Wilson called the "vital objects of a nation's economic structure that tend to paralyze the nation's ability to wage war and...the hostile will to resist." Because of America's opposition to attacking civilians or non-military targets, this bombing would be aimed not directly at an enemy's will, but at the machines and industries that supported that will and its military defenses. The destruction of an enemy's vital industries would destroy its ability to continue to wage war. Wilson viewed high-altitude precision bombing as "an instrument which could cause the collapse of this industrial fabric by depriving the web of certain essential elements―as few as three main systems such as transportation, electrical power, and steel manufacture would suffice."

The technological innovations of the 1930s, which so profoundly inspired the ideas of Walker and Wilson among others, were applied in particular to the large aircraft demanded by America's airlines, and they created a curious situation―large bombers flew faster than small fighters. Thus was born the conviction among airmen, as expressed by Brigadier General Oscar Westover: "No known agency can frustrate the accomplishment of a bombardment mission." The B-17 of 1935 could reach 252 miles per hour at high altitudes, compared with the P-26 front-line fighter, which could not exceed 234. Because speed would allow a bomber to overcome enemy aerial defenses, strategic bombing became the focus of air power development for Mitchell, Walker, Wilson, Wright Field's engineers, and such Air Corps leaders as Brigadier General Henry "Hap" Arnold, commanding the 1st Bombardment Wing, who labored to create the tactical formations, flying techniques, and organization needed for this new kind of warfare.

Upon the recommendation of a War Department committee, known as the Baker Board (named for former Secretary of War, Newton Baker), Congress established the General Headquarters Air Force (GHQ AF) on March 1, 1935. This first American "named" air force, under the command of Brigadier General Frank Andrews and headquartered at Langley Field in Virginia, controlled all offensive aviation in the nine corps areas of the United States, including organization, training, and operations. Powerful opponents in the Army separated the GHQAF from the Air Corps under Major General Westover, in charge of individual training, procurement, doctrine, and supply. The Air Corps remained a combatant arm of the Army, while the GHQAF came under the Chief of Staff in peacetime and the commander of field forces in wartime. The two air components remained divided until March 1, 1939, when the GHQAF came under the control of the Chief of Air Corps.

The MacArthur-Pratt agreement of 1931 made the Air Corps responsible for short-range coastal defense and Army operations on land, but left the Navy as America's offensive force on the sea. Two developments changed this division of responsibility. First, advances in aviation technology made restrictions to short-range operations nonsensical, as when three B-17s intercepted the Italian liner Rex in the Atlantic over 700 miles from America's shores in 1937. Still, the Army continued buying, for the most part, short-range tactical aircraft, including the twin-engine B-18, to support ground operations. Second, Adolf Hitler's successful use of air power as a threat in the Sudetenland-Czechoslovakia crisis of 1938 convinced President Franklin Roosevelt that the United States needed a large air force "with which to impress Germany," and ordered the acquisition of 10,000 aircraft (later 5,500) when Congress appropriated $300 million for the buildup.


Brigadier General Frank Andrews with his staff at ceremonies inaugurating his leadership of the new General Headquarters Air Force's (GHQAF's) command.

When Germany invaded Poland in September 1939, the Air Corps had 26,000 officers and airmen and a heavy bomber force of only 23 B-17s. Chief of Air Corps Arnold had used President Roosevelt's support and British and French orders for 10,000 additional aircraft to launch a huge expansion of the aviation industry. With the fall of France in June 1940, Roosevelt ordered an Air Corps of 50,000 aircraft and 54 combat groups. Congress appropriated $2 billion, eventually, to insure funding for both strategic and tactical air forces. In March 1941 the Air Corps expanded to 84 groups. These actions and events presaged what would become the largest air force in the world equipped with the most modern aircraft available. By December 1941, however, the Army's air force still had only 3,304 combat aircraft, but World War II mainstays such as P-51 Mustang and P-47 Thunderbolt fighters and the B-29 Superfortress bomber still were not operational. All would become part of the U.S. Army Air Forces (USAAF) led by Major General Hap Arnold, established under Army Regulation 95-5 on June 20, 1941, with the Air Corps and the Air Force Combat Command (formerly the GHQAF) as subordinate arms. Less than a year later, Army Chief of Staff George Marshall made the USAAF coequal to the Ground Forces and Services of Supply.

In August 1941, at the behest of the War Department, USAAF Chief Arnold directed four former faculty members of the Air Corps Tactical School to devise an air plan against America's potential adversaries. Lieutenant Colonels Kenneth Walker and Harold George and Majors Haywood Hansell and Laurence Kuter of the newly-formed Air War Plans Division (AWPD) identified in their plan 154 "chokepoint" targets in the German industrial fabric, the destruction of which, they held, would render Germany "incapable of continuing to fight a war." A lack of intelligence prevented the design of a similar plan against Japan. The four planners calculated that the desired air campaign would require 98 bomber groups―a force of over 6,800 aircraft. From their recommendation General Arnold determined the number of supporting units, air-craft, pilots, mechanics, and all other skills and equipment the USAAF would need to fight what became World War II. The 239 groups estimated came close to the 243 combat groups representing 80,000 aircraft and 2.4 million personnel that actually formed the USAAF in 1944 at its wartime peak. The planners had also assumed that they would not have to initiate their air plan, known as AWPD/1, with a complete 98-group force until April 1944. However, they were not allowed the luxury of time. When the Japanese attacked Pearl Harbor four months after the air plan's submission to the War Department, an ill-equipped USAAF found itself thrust into the greatest war in human history.