German aviation technology


Arado Ar 232 Tausendfüßler or “Millipede” cargo aircraft.


Flettner Fl 282 Kolibri. The Germans did wonders in aviation technology at those times. They also introduced the first assembly lined manufactured rotor helicopter in the battlefield. Initially the Kolibri (Hummingbird) was first used for reconnaissance and airlift purposes but soon converted to battlefield use as well

Even before the rise to power by the Nazis in the 1930s, German technology had earned a reputation for precedent-setting breakthroughs. Furthermore, among American air power theoreticians, Gen Billy Mitchell would ultimately gain a reputation for prescience that was at times startling. So, a vignette about Mitchell in Germany in 1922 sets the tone for what was to follow.

In February 1922, Mitchell and his assistant Alfred Verville visited Germany, where fellow American air power pioneer (and some-time Mitchell rival) Benjamin Foulois enjoyed status as a military attaché assigned to The Hague with observer taskings in Berlin. Foulois had gained the confidence of a number of World War I German aviators, including Hermann Göring. As an American observer in Germany, Foulois sent substantial documentation back to the United States, but to his chagrin, he believed it was not properly leveraged to gain an early appreciation of post-World War I Germany.

During Mitchell and Verville’s visit to Berlin, Verville later recounted, Mitchell launched a diatribe one morning against what he likened as automobile engines for aircraft. According to Verville, Mitchell posited that somewhere a German scientist was already working on a new powerplant for use in the next war possibly two decades hence. Mitchell challenged Foulois, with his German contacts, to produce that German scientist.

Foulois arranged a meeting with some Germans, one of whom was an assistant to Hermann Oberth. Oberth explored early notional rocket technologies. One of his later assistants was a young Wernher von Braun, who would later credit Oberth with setting von Braun’s famous career path in rocketry that culminated in the successful Apollo program for NASA.

At the 1922 meeting with Mitchell, the German assistant agreed that “automobile-style” aircraft engines would give way to as-yet unperfected turbines burning kerosene. Discussions and demonstrations next depicted future rocket engines that would burn a mixture of alcohol and something the Germans called “liquid air,” Verville related. He also noted the Germans envisioned a range of 400km and speeds upward of 3,000 mph. As Mitchell’s assistant, Verville was possessed of significant aeronautical acumen. According to accounts, Verville recalled how Mitchell was clearly affected by what the Germans had said and demonstrated, but this early meeting apparently did not have any effect on American policy at that point. Yet history proved Mitchell’s powers of prediction largely correct when it came to the development of better aircraft powerplants, strongly influenced by German explorations.

The emergence of a renewed German military aeronautical capability in the early 1930s was initially masked by various subterfuges, ranging from the location of training fields far to the east, away from casual observation, to the duplicitous use of aircraft that had dual transport and bombardment capabilities. As the decade advanced, Hitler’s emboldened regime revealed more about its nascent air force. In the United States, developments in Germany initially prompted varied reactions. It has been estimated that as many as 75 percent of Americans at one time preferred isolation and noninvolvement in European confrontations in the years leading up to 1941. If postwar tellings of American history tend to make it seem everyone was united in the nation’s posture toward war, such solidarity was achieved only at the expense of Pearl Harbor. An active voice in the pre-war American milieu said European wars were inevitable and interminable, and not the province of Americans. Revulsion at the still-remembered horrors of World War I trench warfare influenced American isolationism. Ironically, the American population was composed largely of European expatriates and their offspring; émigrés who showed, by their very removal to the United States, a willingness to turn their backs on their former homes across the Atlantic.

The isolationists, including some prominent members of Congress and the media, did what they could to blunt the clearly interventionist desires of the Roosevelt administration. The ebb and flow of isolationist support in the United States changed in response to world events as well as actions by the US government in the 1930s and through nearly all of 1941.

Yet even during times of ambivalence toward Europe, some Americans were early observers of German rearmament. A knowledgeable celebrity vector into the new Luftwaffe was provided by famed aviator Charles Lindbergh; he made several visits to Germany in the 1930s, where he was apparently given wide access to new aircraft and organizations.

Lindbergh had an ally for his German forays in the person of Truman Smith, who was assigned as American military attaché to Germany from August 1935 to April 1939. Smith arrived in the midst of world-shaping events. As an army officer, he had first spoken with Hitler as far back as 1922, when the future German leader had no real power. Now Smith had the opportunity to facilitate information gathering on the burgeoning Luftwaffe – information that could inform American defense policy. Smith’s faculties for intelligence gathering and analysis are described by historian Dr. Richard P. Hallion:

Generally, American military intelligence limped along in the interwar years. Most talented officers gravitated towards combat commands, and those that chose intelligence went overseas with little training and few resources. No consensus existed on collection protocols, attachés often just submitting questionnaires to foreign contacts. One notable exception to this general pattern was Maj (later Lt Col) Truman Smith, a gifted and experienced infantry officer who arrived in Berlin as Military Attaché in August 1935. Smith, who blended a military intellectual’s insight with a combat officer’s instincts, quickly realized he faced challenges requiring immediate resolution: his office was receiving contradictory inputs on the state of German aeronautics; and the office’s air intelligence effort was at best sporadic, too-focused on preparation of an annual report that had but limited value.

Col Smith later said in a sworn statement that, “it was my function while I was Military Attaché in Berlin from July 1935 to April 1939 to keep abreast of the strength, organization, and training standards of the German armed forces, to keep myself advised of all economic, political, and military activities and trends that might have a bearing upon German capabilities and intentions of waging war.” Smith went on to say his findings were mostly the result of his own observations while in the field with German troops, or visiting German airfields, military installations, and factories producing war materiel. While Smith acknowledged inputs from Germans as well as US State Department representatives, his sworn statement’s explanation did not mention one of his correspondents by name: Charles Lindbergh.

Lindbergh’s publicized visits to Germany, where he was ostensibly treated with the cordial courtesies extended to a celebrity, prompted the American aviator to offer observations on Germany to Smith, Gen “Hap” Arnold, and publicly. Lindbergh, outspokenly isolationist in his views, has been called the only person opposing Franklin Roosevelt’s pre-war interventionist ambitions who had the charisma and presence to match and even outmaneuver the savvy Roosevelt on some levels. Nor did Lindbergh’s pronouncements only concern isolationism; in 1934 he was critical of the Roosevelt administration’s actions in canceling air mail contracts, and it seems evident Roosevelt did not take this lightly or with pleasure, coming from one with Lindbergh’s credentials.

Official correspondence from Smith to Lindbergh sometimes merged collegial chattiness with official business. In one 1937 letter sent just after the completion of Smith’s important assessment of the Luftwaffe, Smith offers Lindbergh the use of the official attaché automobile to facilitate future travel in Germany. The letter also politely scolds Lindbergh for sending Smith “certain data” via mail instead of diplomatic pouch, where the security of such information was expected to be greater.

A major document arising from the Smith–Lindbergh collaborations is the “General Estimate as of Nov. 1, 1937” submitted by Truman Smith, reporting on evidence of German air activities. Its opening paragraph picturesquely sets the tone: “Germany is once more a world power in the air. Her air force and her air industry have emerged from the kindergarten stage. Full manhood will still not be reached for three years.” The rest of the document is a straightforward analysis of the state of German air rearmament as perceived by Smith, and influenced by Lindbergh. “The astounding growth of German air power from a zero level to its present status in a brief four years must be accounted one of the most important world events of our time. What it portends for Europe is something no-one today can foretell and must be left as a problem for future historians.”

Smith emphasizes several reasons for the growth of the German Air Force at that time, including:

[t]he military aptitude of the German people … The technical and scientific skill of the race … The vision of General Göring who from the start planned a fantastically large Air Force and Air Industry and who at the same time possessed the energy to convert his plans into reality … The unified direction and execution made possible by the dictatorial nature of the German Government … The wise realization of the German air authorities at the start of their rearmament that other nations, especially the United States, were far in advance of them, both in scientific knowledge and technical skill. This humbleness of spirit has been one of the chief strengths of Germany. The old adage that self-dissatisfaction is true strength has never been better exemplified than in the German air development from 1933 to 1937.

Truman Smith expressed amazement at the size of the German aircraft industry at that time. He cited 23 “known airplane concerns with their 46 identified plants, having a potential annual plane production of probably 6,000 planes.” He also acknowledged:

There is every reason to believe that the plants identified only give a part of the picture and that the truth, could it be known, would show a still higher potential production. The scale of the German airplane motor industry is no less impressive. It is ever and again the size of this industry, which forces the foreigner, – and even the American who is accustomed to think in big terms, – to pause, ponder and wonder as to the future.

Smith’s 1937 analysis was prescient as it remarked on German aeronautical technology growth:

Behind this industry stands a formidable group of air scientists, with large and well-equipped laboratories and test fields, constantly pushing forward the German scientific advance. This advance is remarkable. The fact that the United States still leads in its air science and manufacturing skill must not be allowed to overshadow the German achievements between 1933 and 1937 and above all, not to lead to an underestimate of what Germany will achieve in the future.

An intriguing give-and-take characterized American and German aeronautical advances from the 1920s through the immediate post-World War II era. Airfoil research and rationale emanating from Germany’s Göttingen laboratories set the cadence in the post-World War I (and pre-Nazi) era. In 1932 America’s National Advisory Committee for Aeronautics (NACA, forerunner of NASA) acknowledged German precedents in the development of wing airfoils. Soon, NACA’s extensive catalog of varied airfoils with traits suitable for different types of aircraft would be seen as the standard, but it owed much to the pioneering efforts of German scientists at Göttingen. Meanwhile, German rocket scientists and enthusiasts were early to recognize the encouraging work of American rocketry pioneer Dr. Robert H. Goddard. Immediately after World War II, important German theory in wing shapes would once again augment the developments of the postwar NACA in the United States. Dr. George Lewis, Director of Aeronautical Research for the NACA, was predicting in 1936 that Germany would steal the march on state-of-the-art aeronautics unless the United States stepped up its investment in research and infrastructure.

Smith’s November 1937 report about German air power was blunt in its characterization of some other nations friendly to the United States: “[B]ecause on November 1, 1937 the American technical level, which is but one phase of air power, has not been reached [by Germany], is no ground for the United States to adopt the British policy of smugness. If so, we shall be as doomed to the same position of air inferiority with respect to Germany, as France now finds herself in and which Great Britain just as certainly will find herself in tomorrow – unless she realizes promptly her own shortcomings.” Clearly, Smith was sounding an alarm about current and impending German aeronautical prowess.

Smith’s 1937 report offered observations about the intentional defensibility of the German aviation industry:

The German air industry has been strategically located and each factory has been designed on tactical principles. Factories are located as far back from the frontier as possible and the new factories, while many, are relatively small. The principle of factory design is that there may be many separate and small buildings, each with separate powerplant and bomb and gas-proof chambers. Each is designed to operate as a complete airplane factory in time of emergency. This lay out of industry, which gives it great defensive strength against hostile air attacks, must be reckoned an important element of German air industry and air power.

Interestingly, the postwar United States Strategic Bombing Survey (USSBS) noted that the German electric power system, “except for isolated raids, was never a target during the air war. An attack was extensively debated during the course of the war. It was not undertaken partly because it was believed that the German power grid was highly developed and that losses in one area could be compensated by switching power from another. This assumption, detailed investigation by the Survey had established, was incorrect.” The postwar surveys concluded that the German electric power situation was precarious from the beginning of hostilities, and only declined as the war unfolded. Evidence has not been located to suggest conclusively that the USAAF’s disinterest in attacking German electrical power emanated from Smith’s 1937 report, but the apparent divergence merely suggests even an observer as prescient as Truman Smith may have misread some of the signs, or possibly been misled by his German hosts.

In November 1937 Smith enumerated Germany’s frontline combat aircraft in production as the Heinkel He 111 twin-engined bomber, considered “heavy”; the Dornier Do 17 bomber that he classified as “light”; and the Messerschmitt Bf 109 fighter. They would all be encountered in the skies over England less than three years later. The collaboration of Smith, Lindbergh and Smith’s assistant, Maj Albert Vanaman, came up with a remarkably accurate assessment of Luftwaffe strength in November 1937:

The actual November 1st strength of the German Air Force is probably from 175 to 225 squadrons. If we take a mean between these figures of 200 squadrons, we find Germany to at present possess 1,800 first line planes in units, 600 first line planes in reserve units or a total of 2,400 planes.” In his research, historian Richard P. Hallion has confirmed the accuracy of these educated estimates, noting: “at that time the Luftwaffe had 213 squadrons and an approximate first-line air strength of 2,356 planes.”

The seminal November 1937 report characterized the skills of German aviators: “The level of flying ability reached by the German air power still leaves much to be desired, both by our standards and theirs also. While good potential pilots, the Germans must still be rated as unrefined. However, they have made great progress since 1933. The present flying of units would be better still were it not for the air force expansion.” But, the report’s authors cautioned, any current and momentary German personnel performance difficulties “must not be allowed to obscure the certainty that these deficiencies will gradually cease to exist. If any foreign country feels self-satisfied in the matter of the superiority of its training, it will receive a rude awakening in the not too distant future.”

The November 1937 report judged German air power mature enough “where it must be given serious consideration as a powerful opponent of any single nation.” Citing “qualified officers” who had recently inspected the air forces of Germany, as well as of Great Britain and France, the report was blunt in its assessments: “Technically, Germany has outdistanced France in practically all fields. Germany is on the whole superior to Great Britain in the quality of her planes, but is still slightly inferior to Great Britain in motors, but rapidly closing the gap.” British and French air force training levels were judged to be better than those in Germany in late 1937, but during that year Germany was seen to reduce the gap in training with those countries.

Citing “a highly competent observer, well acquainted with both American and German air developments,” Truman Smith’s November 1937 report predicted that if the “progress curves” of both German and American air developments over the previous two years were replicated in the following two years, “Germany should obtain technical parity with the USA by 1941 or 1942.” The report makes an ominous observation: “If, however, America makes a single blunder, or if some important incident, whether political or a conflict of views within the armed forces, should slow down her present development, German air superiority will be realized still sooner.” Smith was succinct in his summation: “In November 1937 it appears that the development of German air power is a European phenomenon of the first diplomatic importance. The upward movement is still gaining momentum.”

Smith’s seminal 1937 report qualifies some of its attached lists of German Air Force units, strengths, and factory locations with the notation that secrecy made it difficult to judge if all such tallies were complete and up to date. Of interest is a map showing that German aircraft motor construction plants tended to be located deep in Germany and somewhat concentrated. This situation appeared corroborated later as the war unfolded, causing the USAAF to make a conscious decision about delaying a campaign against German aero engine production until sufficient aircraft were on hand to permit safe and recurring long-range missions to that part of Germany to cripple motor production, as would be seen later.

If Truman Smith did not readily name Charles Lindbergh at the time the November 1937 report was drafted, it is interesting to note that in the 1950s, while writing about his air intelligence activities in Germany two decades earlier, Smith gave “special reference to the services of Col Charles A. Lindbergh.”

Lindbergh’s access to German airspace in the late 1930s seems, in hindsight, surprisingly unfettered, unless Germany’s intent was that the American aviator should see many Luftwaffe fields as he transited the country in his own aircraft. In late October 1937, Charles and Anne Lindbergh flew from Germany to their residence in England, affording the opportunity to overfly at least six Luftwaffe airfields, at which Lindbergh observed and reported to Truman Smith the presence of various fighters, trainers, and Do 17 bombers. Over the following year, Lindbergh lobbied a number of American policymakers as he continued to express concerns over the growing might of German air power. He indicated concerns that France could not effectively defend against a German attack, and he expressed some doubt about Great Britain’s abilities at defense, although he gave the country higher marks than France. He presumed Russian aircraft construction to be effective, yet inferior to the manufacturing abilities of the United States. All of which, he told Joseph P. Kennedy, the US ambassador to Great Britain, suggested a European war could damage all combatants and lay Europe open to the spread of communism. Lindbergh also urged USAAC Gen Henry H. “Hap” Arnold in November 1938 to visit Germany to learn firsthand how the Luftwaffe and industry were developing.

As Germany expanded its grip on portions of the European continent by the fall of 1940, the availability of raw materials for aircraft construction – mainly aluminum and steel – appeared assured with access to Hungarian bauxite resources and Silesian aluminum plants and coal deposits. This was reported by Truman Smith in September of that year as he once again endeavored to provide an updated forecast of German aviation growth in the coming year. Using the information available to him, Smith posited in September 1940 that Germany would produce a minimum of 42,000 aircraft of all types between September 1, 1940 and September 1, 1941. German records indicate the number was closer to 12,000 for that time period. But if Smith’s estimates were based on capacity, he could not have known for sure the political and strategic decisions that went into the actual construction effort for that period.

The intrigue of life for an American in Germany in the 1930s was embraced by Truman Smith. His proactive efforts to quantify German military growth and strength provided a basic guide that appears to have subsequently informed target priorities after the United States became embroiled in the European war. Perhaps the ultimate irony of the isolationist counsel that Smith’s newfound friend Charles Lindbergh gave to all who would listen came on December 11, 1941 when Hitler, only days after the Japanese attack on Pearl Harbor, removed all ambiguity by declaring war on the United States.

For his efforts at creating a picture of German rearmament, Col Truman Smith was later awarded the Distinguished Service Medal. The citation for that award summarized his contributions:

As Military Attaché to Germany during the fateful period from August 1935 to March 1939, Col Smith accurately reported Nazi Germany’s rapidly growing military strength and intentions and greatly facilitated the efforts of the United States Army to keep abreast of German organization, tactics, and equipment. His reports stimulated action and were in a measure responsible for the manner in which the Army developed its plans to build up the military strength of this country. Upon the return of Col Smith to the United States his intimate and expert knowledge of the enemy was of importance to the formulation of Allied strategic plans.

If Germany and Japan won early victories in part due to their stunning, decisive offensives, the air of invincibility the Axis powers projected in 1942 was sobering, and in need of studied evaluation. By 1942, the Royal Air Force (RAF) had shown the Luftwaffe could be thwarted, yet the depth and breadth of the German Air Force was far from mapped by the Allies at this early stage of the war.

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