Air Policy and Defense *

Highlights on some of the problems associated with the operation of American aircraft in warfare

By Edward Warner
Vice-Chairman, Civil Aeronautics Board,
lately Technical Assistant to W Averell Harriman on British Mission

* Excerpts from an address before Foreign Policy Association Forum on October 25, 1941

The sudden demand of the American public for information on our aircraft participating in the present war has resulted in the rise of innumerable pseudo experts who have poured out misinformation in alarming volume. Scarcely a day passes in which we do not receive several letters from responsible citizens deeply concerned lest there be some truth in the rantings of these self-styled authorities about the quality of our aeronautical material and the ability of our military leaders. It is therefor with great satisfaction that we are privileged to present the views of one who has made aviation his lifework and has made important contributions to the progress of aviation for more than a quarter of a century.

A former editor of Aviation, the author needs no introduction to our readers. He has been in the forefront of aeronautical progress in peace and in war and has made many contributions to aeronautical engineering, design, air transport operation, and other branches of aeronautics. During his recent stay in England, where he served as technical assistant to W Averell Harriman, he had occasion to work at close range on some of the vexing problems associated with the transplanting of American aircraft to foreign fields of operation.

These excerpts, from an address delivered to a recent forum on the general problems of defense, are intended for a non-technical audience and only a few of the many factors of the problem are here discussed. No attempt has been made, in the limited space available, to present a complete treatment of the essentials of the relation of American to European aeronautical engineering. It is our hope, however, that we may be able to offer in future issues, more specialized discussions of the several phases of this subject by the author.


The alluring possibilities that air power presented to the aggressor had a large share in starting the war; air power now has a large share in determining its outcome. The considerations that determine the effectiveness of air power's use have become vital to every living human being.

Being largely a war of air power, this is largely a war of air material. The material problem is of particular interest to Americans, for it is with material that we are currently taking part in the war in the air. Thousands of American airplanes have been shipped to the British forces. Tens of thousands of others will join them, in a mounting tide until the final victory in which they will have greatly shared has been won.

The performance of American military aircraft, and the service they have given in England and the welcome that they have found there, have been the subjects of a great deal of recent discussion. Questions of aircraft design have acquired a popular interest that they never had before, and they have become the subject of hot popular controversy. Extreme and spectacular statements have received wide circulation. What are the facts?

The basic facts are those that relate to the general quality of the aircraft, and their fitness for specialized military service. Contrary to frequent allegations of national self-exaltation or of national self-depreciation, there is neither general and continuing virtue, nor general and continuing defect, in American aircraft, nor in British, nor in German. Research goes on in all major nations. Aeronautical engineering follows the same general methods, uses much of the same data, and is subject to the same physical laws in all. In all these countries, men of great ability have applied their talents to the design of aircraft and their engines and auxiliaries, and to the improvement of the methods of producing the equipment. There have been periods when the arts of aeronautical engineering have been allowed to lapse into the doldrums in one country or another, with a general inferiority of the national product resulting for the time being; but there has been no such period in the last five years for any of the countries that I have mentioned. I think it can be honestly claimed that American research and invention have led the way introducing more important new features into aircraft design in recent years than have those of any other country; and I want to emphasize that, because the charge is so often and so inaccurately made that the organization of American aeronautics has been marked by suspicion and hostility towards innovation. I repeat that not even fragmentary support for any such charge can be drawn from the actual record. I would not venture, however, to extend that claim into a claim of any general and inherent superiority for the American product. Still less could any general inferiority be truthfully admitted.

If there is no universal superiority of one nation over another, however, there are many instances of the application of particular efforts, in one nation of another, to the solution of a particular problem on the development of a particular type. A few of the more conspicuous instances of that sort may be mentioned — instances in which we have followed one line of development, while the British or perhaps all of Europe have followed another, with the result that for certain special purposes our aircraft do possess special advantages, while in other respects they work under special handicaps.

The first such instance is that of the heavy bomber. Many countries — Germany and Russia among others in recent years — have at some time experimented with aircraft of giant size. In most European countries such trials have been a passing fancy, and a dominant consideration in determining policy on the size of the aircraft to be built in quantities has been a desire not to put too many eggs into one basket, but rather to secure a larger number of comparatively small units.

The British had been first to use four-engined airplanes for commercial purposes, and most persistent in developing their air transportation around very large aircraft; but to the four-engined bomber, although they continued development work and now have two excellent types in regular service, they gave a comparatively secondary place. In this country, on the other hand, for at least five years the directive policy of the Air Corps has viewed the large bomber, in the form colloquially known as the "flying fortress," with unvarying favor, and has given it a consistently high priority in procurement planning.

The heavy bomber is now recognized to have a number of special advantages for the present type of operations. Among the most important are its greater relative bomb-carrying capacity over long ranges, the lighter bombers being essentially short-range types; its ability to carry individual bombs of very large size, for attacking concrete buildings and other stoutly resistant structures; and its reduced personnel requirement, as compared with the two or three light bombers that would be required to carry the same military load as one heavy one. Even the Germans, who have been persistently faithful to the light bomber for overland raiding, have turned to the development of larger types for the long-range operations of the campaign over the Atlantic. The high development of the bomber of 40,000 lb weight or more in the years since 1935 constitutes one of the greatest of America's special contributions to the preparation of victory.

Another interesting point for illustration, and one that has been the occasion of some intensely acrimonious public discussion by aeronautical writers, concerns the power-plant. Both America and Britain build both air-cooled and liquid-cooled engines; but the concentration of effort upon the air-cooled types has been more intense in America than in Europe. There has been more hope in America that air-cooled engines could be made to serve all purposes, and the American air-cooled power-plants have made a world-wide reputation; but the British have built many more liquid-cooled engines than we have, and they have advanced more rapidly in increasing the power of the individual engine toward the present maximum of some 2,000 hp. Since most high-performance fighting aircraft are designed around liquid-cooled engines, our less intensive activity on that type of engine has imposed limitations on fighter development. Liquid-cooled power-plant are now in production here, and the development of new models of higher power is being pressed forward with all possible vigor; but we lack the British advantage of continuous development and large-scale application over the past decade.

The last point that I select for mention is that of the design of aircraft engines for maximum performance at very high altitudes. There are two general ways of making an aircraft engine maintain its full power in the region of rarefied atmosphere. Dependence may be placed entirely on a supercharger built into the engine itself; or there may be a supplementary provision of a supercharger attached to the engine as an accessory, and not mechanically connected to it, but driven by exhaust gas. European development has concentrated on the first method; America has given much attention to the second. The auxiliary type of supercharger has been the subject of study and occasional experiment in England, in Germany, and in France, but only in America has the assault on the enormous technical problems that it presents been so continuous, and engaged such an amount and quality of engineering and inventive talent, as to realize practical serviceability. The auxiliary supercharger, driven by an exhaust turbine, is already making it possible to conduct bombing expeditions at altitudes well above any that were previously attainable. It may rank with the development of heavy bombers among major American contributions to the aeronautical technology of this war.

In addition to the differences in development policy and in specialized national interest, there have been the differences between a nation at peace and one already at war. In time of peace, the military aircraft is commonly judged primarily as a flying-machine, and only secondarily as a fighting craft. In time of peace, the fitting of armor seemed an outrage against aeronautical science; but after the fall of 1939 it took only a few weeks of accumulating experience of the men who were actually being shot at in the air to convince designers that the weight of a little judicially-distributed steel plate would be weight well expended, even though it increased the landing speed of the airplane by three miles an hour, or lengthened the take-off run by 100 ft.

There was, for example, the case of the leak-proof fuel tank. In 1919, with recent unhappy memories of aircraft coming down in flames, it was a general assumption that protection of the tank against ready loss or ignition of its contents by enemy fire was essential. Reasonably efficient means of leak-proofing tanks were developed; but leak-proofing was heavy, and bulky, and sometimes shortlived. It gradually disappeared from the art, only to return when another war began to furnish tragic reminders that bullets still punctured unprotected tanks and drained the fuel away, sometimes with fire resulting.

To the problems of design and construction must be added those of getting the aircraft into service. At least three-quarters of such troubles as have been experienced with American aircraft in the British Service — and there have been some troubles — have been due to nothing inherent in the aircraft themselves, but have arisen out of the problem of fitting different types of equipment together, and of providing all of the information and all of the auxiliary supplies that were necessary for efficient use. Fortunately one may now speak of these difficulties primarily in a historical sense, for most of the troubles that were apparent six months ago have now either been entirely overcome or are well on the way to disappearance.

To realize the troubles that may be experienced in moving even the best of equipment from one environment to another, it must be remembered that a military airplane does not operate as an independent unit, but as a working part meshed into a vast and intricate system. Where British and American designs for auxiliary equipment differ, there must be a change of practice somewhere in order that the airplane and its consumable supplies may operate together. Bombs have to fit bomb-racks; ammunition has to fit guns; and guns to fit mount. Changes in gun installation may involve a change in firing control running all the way to the pilot's cockpit. Radio sets must go into the space provided for them in the aircraft; but they must also have the frequencies and the other characteristics to enable them to work within the framework of the communications system established in the country where the aircraft is to be operated, the alternative being to make extensive revisions in the ground equipment.

Even the most trivial details can be annoying. Both British and American Services, for example, have a standard practice in the folding of maps for ready reference; but the practices are different enough to make it difficult to keep the standard maps of one country conveniently in a map-case designed to hold those of the other. Other points have been far more important. There was a case, for example, in which the necessary changes in radio and other electrical equipment required a change in the characteristics of the generator driven by the engine. That in turn modified the engine's vibration characteristics, and it was only after a period of very urgent shop and laboratory work that means of overcoming the resultant mechanical difficulties were found and introduced.

Some differences require a period of familiarization for the pilot before he can feel at home with the new equipment. It appears to be true, for no particular reason, that the natural position of the control stick in most British aircraft is farther back toward the pilot's body than in similar American machines. A pilot accustomed to flying with his arm in a certain position finds any other position uncomfortable until he gets used to it. A more important matter is the habitual use of quite different brake control in the two countries; and there are others.

Aircraft can be move from place to place at very high speed, but their lives in useful service may be short when they arrive unless a considerable supply of spare parts has kept pace with them. Not only is a stock of spare hardware needed, and tires, and engine and propeller parts and instruments and the like, but also special tools, and working-benches, and jigs for re-aligning wings and bodies after they have been damaged and distorted, and other special fixtures. Shortage of spares is often a grave handicap for aircraft that are operating within a few hundred miles of the factory where they were built. The handicap is vastly greater, and a proper organization is proportionately more difficult to work out, when the needs must be communicated in coded cables, and the needed material dispatched across an ocean. Even in the relatively simple and unmechanized days of our grandparents, there was current a sort of house-that-Jack-built jingle that worked up to a grand climax of how the battle was lost for the want of a horseshoe nail. Battles in the air may be lost for the want of lubricating oil of the precise specification on which the engines were designed to run; for the want of an adequate supply of exactly the right type of spark plugs; or for the want of the coils which will convert a radio set to enable it to operate on the proper frequencies.

Another difficulty often arising has been that of getting adequate instruction books and such material to all the places where they will be needed. The airplane often outruns or becomes separated from the information that ought always to be in the hands of those charged with operating and maintaining it. I dwell upon such seemingly small matters because, small as they seem, they are capable of making a vast amount of trouble, and have on occasion actually done so; and because of the satisfaction with which I can express my confidence that the problems of supply of material and of information, and of modification where necessary to fit a change in environment, and of accustoming personnel to the unfamiliar characteristics of the trans-Atlantic equipment, are all progressing towards more and more complete solutions.

Such problems are inherently those of the early stages of association. Arrangements for each new type of aircraft to be preceded by an account of its special qualities and operating demands, prepared from the point of view of the pilot, now insure that the first examples of the type to arrive will not be received as unproved strangers, but with the confidence that goes to the bearer of impeccable credentials.

The role of the service representatives of the American industry is of enormous importance in this work of familiarization, as well as in dealing with those mechanical troubles to which all highly-stressed machinery is occasionally subject. There has been a growing appreciation that delicate and complex mechanical equipment, for its most efficient operation, needs occasional attention and operating counsel from engineers and mechanics who have known that equipment from its inception. The resultant attempt to keep the number of service representatives in England of the American industry commensurate with the rapidly growing amount of American equipment there is a recognition of one of the fundamental requirements of getting the most out of the aircraft and their engines and accessories. The guidance that American-trained experts can give is particularly important under the conditions of a country at war, with skilled labor never available in quantities to meet all the demands, and with every resource of manpower and womanpower, and every expedient for speedier training for mechanical jobs, necessarily pressed to the limit.

I have been dwelling particularly on military air material, but civil aviation is also of national importance, even in time of war. It has the importance that always attaches to the swiftest possible transportation of persons, goods, and communications in times of special emergency; but is also has the significance of an instrument of national policy in international relations, and of a vital instrument of military communications. For embattled Britain, air transport supplies communication and conveyance between areas of which the connection by surface means of transport is so slow and roundabout as to be virtually non-existent. The pressure is so great that the would-be traveler by a British transport plane finds it necessary in many cases, and wise in almost all, to support his application with a government-issued certificate of priority. We have reached no such stringency as that, though we have approached it on the trans-Atlantic service; but we too are deeply dependent upon air transport in this crisis, at home, across both oceans, and for swift travel and exchange communications within the western hemisphere.

There has been an impressive manifestation of hemispheric unity in the steps that the American Republics have taken to uproot the ominously penetrating German-controlled lines.

It becomes increasingly important that the air transport systems within the United States, and those connecting us with neighboring countries and extending overseas, should operate during the emergency with a sole concern for the swiftest possible adaptation to national requirements, in the order of their urgency, and for the rendering of the greatest possible aggregate of service with the greatest economy of men and material. They operate under a legal framework drawn in terms of peace conditions. It provides for development primarily through the initiative of the individual airlines, with the agencies of Government giving their applications judicial consideration in accordance with an established judicial procedure, rather than for Government initiative and sponsorship of the establishment of services where the national interest requires them; but air transport, especially in the international field, has now to meet the test that is to become the universal touchstone of all our pursuits and professions. It has to be the expression of a national purpose that gives an unquestioned priority to the needs of the present emergency, and very little weight indeed to any considerations that do not coincide with the emergency's requirements. Considerations of competitive positions either for the present time or for the period after the war recede into comparative insignificance. It success in the years immediately ahead will not be judged by ordinary standards, but by the accuracy with which it conforms to the emergency's demands and finds solutions for the emergency's abnormal problems.

This article was originally published in the December, 1941, issue of Aviation magazine, vol 40, no 12, pp 48-49, 186, 188.
The original article includes a photo of an early production B-17E and a photo of Mr Warner.
Photo of B-17E credited to International; photo of Mr Warner is not credited.
A PDF of this article is available.