Chapter 3 PEACE

The Future of Aerial Defence.

In the evolution of aviation during the war the conclusion has been reached that the most remarkable lines of development at the Armistice were in the direction of ground and night fighting, torpedo attack and long-range bombing, exemplifying respectively the three spheres of air operations-military co-operation, naval co-operation, and the strategic use of aircraft. It must be remembered that this progress in tactics and strategy, in the machine, and the airman's skill, was made in the short period of four years, and that every war has started with a great advance in scientific knowledge, accumulated during peace, over that obtaining at the close of the previous war. We may therefore assume, provided the danger is averted of a retrograde movement from recent scientific methods to pre-war conditions-sabres, bayonets, and guns-that by the outbreak of another war on a large scale, which we hope may never occur, the knowledge of Service aeronautics will have increased immeasurably since 1918, and may be, not a contributory, but a decisive factor in securing victory.

The period since the Armistice has been employed in the reduction and consolidation of the Royal Air Force. In England the cadre system has been adopted, while abroad the greatest concentration of effort is aimed at, with Egypt, at present the most important strategic point in the Imperial air system, as the centre of activity. Iraq is being handed over to the control of the Royal Air Force, whose share in the policing of overseas possessions is likely usefully to grow provided any tendency to the concurrent building up of a large ground organization is withstood. The advantages of aircraft for "garrison" duties lie, under suitable geographical conditions, in their swift action and wide range, their economy, and, during disturbances their capacity for constant pressure against the enemy without fear of retaliation. One of the main problems is at present that of personnel. Service flying is restricted to comparatively young men, and therefore the majority of officers can only be commissioned for short periods. For this reason the experiment is being made of taking officers direct from civil life on short engagements, and at the same time endeavouring to ensure, by technical and general education, that the Royal Air Force shall not become a blind-alley occupation.

Though it is difficult to foretell on what lines aircraft will develop for any one purpose, as in the past, the problem of military co-operation will perhaps be less complex than that of co-operation with the Navy. It will probably consist of improvements along the lines already indicated, such as increased range, speed, climb, man?uvrability, offensive armament, armour, the assistance of tank and anti-tank action, and the utilization of gas. Fighting will undoubtedly take place at very high altitudes to keep the enemy's fighting machines away from the zone of operations-necessitating the development of the single-seater so as to increase climb and man?uvrability, and obtain, if possible, a speed of 200 miles an hour at 30,000 feet. Cavalry, unless retained, as I think they should be, in the form of mounted machine-gunners, will, I think, disappear in European warfare, but infantry will remain, and it will be the object of aircraft to assist their advance by reconnaissance, ground attack, artillery and tank co-operation, and the destruction of the enemy's supplies and communications. In this connection ground tactics and air tactics must develop pari passu and commanders of Corps and Armies must work out during peace training the fullest schemes for the most intimate co-operation between air and land forces.

The future of naval co-operation is a difficult problem, more especially as there was no major naval engagement after Jutland in which aircraft could be used, and consequently we have little to go on in estimating their practical value in direct co-operation with the fleet. It is impossible at present to judge between the conflicting opinions as to the future of the capital ship, but it is certain that aviation will materially modify naval tactics and construction. Coast defence, reconnaissance, anti-submarine work, escort, and the bombing of enemy bases, will doubtless continue and develop with ever-increasing machinery and equipment; but torpedo attack by aircraft may reach a point where the very existence of opposing fleets may be endangered. It is already questionable whether a battleship could survive an attack launched by even a small force of this mobile arm.

As was the case during the war, the action of aircraft at sea is restricted by range, the difficulty being to find the mean between the opposing conditions of radius of flight and limitation in the size of aircraft imposed by the deck-space of "carriers," but there is reason to suppose that on the one hand engines will be so improved as to afford a sufficient radius of action to comparatively small aircraft, while, on the other, devices will be found to economize deck-space.

Fleets operating near the enemy's coast will be vulnerable from land aircraft bases, and thus close blockade will be rendered increasingly difficult. The possibility of gas attack on enemy bases from the air in co-operation with submarines and of effecting a blockade by this means must be envisaged.

Since the Armistice the operational work of the Royal Air Force on behalf of the Navy has been conducted under the auspices of the Admiralty. Improvements have been made in large flying boats and amphibians, especially with a view to facilitating their landing on "carriers" and the decks of battleships. There has also been considerable progress in the construction and use of torpedo aircraft.

The war lasted long enough to prove the effect of the strategic offensive by air. In spite of the dictates of humanity, it cannot be eliminated. It is true that modern war is inimical to the progress of mankind and brings only less suffering to the victors than to the vanquished. To ensure peace should therefore be our ideal. But a great war once joined is to-day a war of peoples. Not only armies in the field, but men, women, and even children at home, are concentrated on the single purpose of defeating the enemy, and armies, navies, and air forces are dependent upon the application to work, the output of war supplies, and, above all, the morale of the civil population. Just as gas was used notwithstanding the Hague Convention, so air war, in spite of any and every international agreement to the contrary, will be carried into the enemy's country, his industries will be destroyed, his nerve centres shattered, his food supply disorganized, and the will power of the nation as a whole shaken. Formidable as is the prospect of this type of air warfare, it will become still more terrible with the advent of new scientific methods of life-destruction, such as chemical and bacterial attack on great industrial and political centres. Various proposals, such as the control of the air effort, service and civil, of all countries by the League of Nations, and even the complete elimination of aviation, have been put forward as a means of avoiding the horrors of aerial warfare and its appurtenances, but they are untenable, and any power wishing and able to sweep them aside will undoubtedly do so.

A future war, as I see it, will begin something after this manner, provided either side possesses large air forces. Huge day and night bombers will assemble at the declaration of war to penetrate into the enemy's country for the attack of his centres of population, his mobilization zones, his arsenals, harbours, strategic railways, shipping and rolling stock. Corps and Army squadrons will concentrate in formation to accompany the armies to the front; reconnaissance and fighting patrols will scatter in all directions from coastal air bases to discover the enemy's concentrations and cover our own; the fleet, whatever its nature, will emerge with its complement of reconnaissance and protective machines and torpedo aircraft for direct action against the enemy's fleet. A few fighting defence units will remain behind.

But it must not be imagined that these functions will be carried out unopposed. Local battles in the air will occur between fighting machines for the protection of specialized machines, while the main air forces in large formations will concentrate independently to produce, if possible, a shattering blow on the enemy and obtain from the outset a supremacy in the air comparable to our supremacy on the sea in the last war.

In mobilization the time factor is all-important. Our national history has been one of extraordinary good fortune in this respect, but the margin allowable for luck is becoming very narrow and, whereas in 1914 it was some twenty days between the declaration of war and the exchange of the first shots, in the next war the air battle may be joined within as many hours, and an air attack launched almost simultaneously with the declaration of war. In modern war the mobilization period tends to shorten, and every effort will be made towards its further reduction, since mobilizing armies are particularly vulnerable from air attack.

Civil Aviation as a Factor in National Security.

The picture I have drawn may appear highly coloured for the reason that no country is likely for some time to possess sufficiently large air forces to obtain a decisive victory, or at any rate an uncontested superiority, at the outbreak of war. Though in air, as in every other form of warfare, attack is more effective than defence, we cannot afford to keep our air forces up to war strength in peace any more than our Army or Navy.

The problem, from a military point of view, is therefore to ensure an adequate reserve and to maintain our capacity for expansion to meet emergencies. The number of units maintained at war establishment should be the absolute minimum for safety and of the type immediately required on mobilization, i.e. long-range bombing and naval reconnaissance squadrons. The remainder should be in cadre form. We can, of course, maintain a fixed number of machines and pilots in reserve for every one on the active list, but, although some such system is necessary, on a large scale it is open to many and serious objections. First of all, even on a cadre basis, it means keeping inactive at considerable cost a number of machines which may never be used and which, however carefully stored, quickly deteriorate. Knowledge of aeronautics is still slender and improvements are made so continuously that machines may become obsolete within a few months. Moreover, the growth of service aviation in peace must tend to become artificial and conventional rather than natural, and this will react on design and construction, which will be cramped, both technically and financially, within the limits imposed by service requirements.

It is obvious therefore that the capacity of the construction industry to expand cannot be fostered by service aviation alone; furthermore, in the event of another war of attrition, expansion will be more essential than any amount of machine reserve power immediately available, and in the event of a war of short duration that power will win which has the greatest preponderance of machines, service or civil, fit to take the air. The asphyxiation of a large enemy city, if within range, can be done by night-flying commercial machines, and it would require a defending force of great numerical superiority for its successful defence.

Whether, therefore, from this point of view, or others, which I will mention later, another solution must be found, and this lies in the development of civil aviation. An analogy in the Navy and the Mercantile Marine has long been apparent. "Sea power," says Mahan, "is based upon a flourishing industry." Substitute "air" for "sea" and the analogy is still true. The Navy owed its origin to our mercantile enterprise and to-day it depends upon the Mercantile Marine for its reserve power of men and material. In the same way must air power be built up on commercial air supremacy. If we accept Mahan, or the dictum of any other great naval or military historian or strategist, a service air force by itself is not air power, and after a brief if brilliant flash must wither if reserves are not immediately at hand. A large commercial air fleet will provide, not only a reserve of men and machines, but it will keep in existence an aircraft industry, with its designing and constructional staffs, capable of quick and wide expansion in emergency; and such an industry will not be employed on the design of contrivances for use in a possible war, but on meeting the practical requirements of everyday air transport and navigation.

Thus a natural, practical and healthy, as opposed to a stereotyped and artificial, growth will be ensured. Our naval supremacy is largely attributable to the interest which the people as a whole have traditionally taken in naval policy; in other words, to the fact that we are a seafaring nation. Similarly air supremacy can only be secured if the air-sense of the man in the street is fostered, and aviation is not confined to military operations, but becomes a part of everyday life. At the present time commercial aviation is far too small to play the part of reservoir to the Royal Air Force-an object which must constitute one of the principal claims for support of the nucleus already in existence.

Civil Aviation as an Instrument of Imperial Progress.

Civil aviation, however, has not only an indirect military, but, with its superiority in speed over other means of transport, a direct commercial utility. The nation which first substitutes aircraft for other means of transport will be more than half-way towards the supremacy of the air. Moreover, as the Roman Empire was built upon its roads and as the foundations of the British Empire have hitherto rested upon its shipping, as steam, the cable and wireless have each in turn been harnessed to the work of speeding up communications, so to-day, with the opening of a new era of Imperial co-operation and consultation, this new means of transport by air, with a speed hitherto undreamed of, must be utilized for communication and commerce between the various portions of the Empire.

A comparison of the French and British attitudes towards civil aviation clearly demonstrates the two policies I have mentioned. Both France and England grant subsidies-France the very much larger sum-but the great difference lies in the objects aimed at. French policy is fostering civil aviation as a part of its military policy and, a portion of the subsidy being given to machines fulfilling service requirements, there is a strong tendency for French civil aviation to be military air power camouflaged. British policy, on the other hand, should aim at fostering civil aviation primarily as a commercial concern and believes that air commerce is the basis of air power as a whole. We are prepared to face the tendency of military and civil machines to diverge if that divergence is essential to the commercial machine.

An alternative to the British policy of maintaining a small air force and fostering commercial aviation as a reserve is the Canadian plan of a small air force training school and a civil Government flying service with such objects as forest patrol, survey and coastguard duties, the work being carried out on repayment for Government departments, provincial governments and private corporations. The former method, allowing of independent commercial expansion, is better suited to British mentality and requirements, but its success will depend on a genuine endeavour to make commercial aviation the real and vital basis of our air power. Experience in commercial operation cannot be gained by the exploitation of air routes or the carriage of mails or passengers under Service auspices. It is only by running transport services, as far as possible under private management, that operational data can be obtained, economies effected, and the design of strictly commercial machines improved.

To sum up. Military air supremacy can best be assured by the intensive development of industrial air organization for commercial purposes. The conception of civil aviation as the mainstay of air power as a whole is right. Service aviation is bound by technical and financial limits; its scope confined to the requirements of war. Civil aviation, on the other hand, opens out a prospect of productive expansion. The steady growth of the Continental services is already beginning to demonstrate the importance of air transport.

Financial and Economic Problems.

The commercial exploitation of air transport is passing through a period of experiment, and suffering in the general war reaction from the incapacity of the public to think of aviation except as a fighting service. The machines hitherto used on the lines to and on the Continent are principally converted war machines, and to transform military into commercial craft and to use them as such is of small assistance to civil aviation, which requires reliable, economic machines as one of the basic conditions of its financial success. The cost of running an air transport service is considerable. Depreciation is one heavy item of expenditure. New machines must be evolved suitable to the requirements of mail, passenger and freight transport, but, in the present state of financial stringency, capital is not forthcoming for experiment unless there is every promise of a safe return. Then there are the expenses involved in general ground organization, maintenance, fuel, insurance, etc. The question is how can we carry on until the really economic type of commercial machine is evolved. It will never be evolved unless there is continuous flying and a continuous demand for new and improved machines for commercial work. To meet this in France, the Government came forward with a liberal grant of subsidies which have now been increased and placed on a more favourable basis, permitting of a very considerable reduction in the fares for transport by air. The British Government has also granted a subsidy for British firms operating on the cross-Channel routes, which it is hoped will place them before long on a sound, self-supporting, commercial basis. Part of this subsidy is allocated to assist transport companies in obtaining the latest type of commercial machines on a hire purchase system. With a few services properly supported by the State we shall pull through the experimental period of civil aviation.

The services to the Continent, although the distance is on the short side for the merits of air transport to be properly demonstrated, effect a considerable saving in time, and it is certain that the amount of mail, especially parcels, carried on these routes will continue to increase and lead to the eventual adoption of normal rates for air postage. An extension of the use of aircraft as the regular means of carrying mails will be of great assistance in the development of air transport. Aircraft revolutionize the speed of intercommunication by letter, and banks and financial houses will gradually realize that large savings can be made by utilizing air mails for the transaction of business. A difficulty lies in the fact that the area of the British Isles is not very favourable for an extensive air mail service, which can only operate by day, since by the existing means of transport mails are carried during the out-of-business hours and can generally reach their destination in a night, while the distances to Paris and Brussels are too short to afford outstanding advantage.

Lastly, we require public support and a spirit of confidence in the air. This can only be secured by increased reliability, reduction of charges and keeping the public informed of the progress made. It is the nature of man to distrust new departures. He disliked the introduction of mechanical devices into the Lancashire weaving mills. He scoffed at the steamship and railway. To-day he is inclined to treat as premature the serious exploitation of the air. In spite of the great decrease of accidents, in spite of the increased comfort of air travel, in spite of increased regularity, the average person is slow to realize that the communication of the busy man of the future will be by air. The majority of the business world is too conservative to make general use of the opportunities offered by aircraft for the quick transmission of its correspondence, while, though speed must be paid for, the high fares hitherto charged have deterred the general public from substituting the aeroplane for the train or boat. The running costs represented by these fares are being materially reduced as a more economic machine is evolved, and the reduction of fares which helps to place competition with foreign subsidized services and with the older forms of transport on more equal terms must for a time depend upon the assistance of Government grants.

Weather Conditions and Night Flying.

The safety of the machine and the reliability of an air service largely depend on accurate weather forecasts. In order to co-ordinate the meteorological work of the country as a whole, and for the special assistance of aviation, the Meteorological Services of Great Britain have been amalgamated under the Department of Civil Aviation, and, working in close co-operation with the Communications Branch of the Department, have made improvements in the rapid collection and distribution of meteorological information for all purposes. In addition to the forecasts issued four times daily, collective reports are issued hourly by wireless from the London terminal aerodrome at Croydon and copies are distributed to transport companies and others concerned.

A feature of meteorology which is often overlooked is its economic value. By making use of a knowledge of the wind at different heights, aircraft can complete journeys more quickly than would otherwise be possible, and thereby save their own fuel and their passengers' time. This will be specially useful in the tropics where the regularity of the surface winds has its counterpart in the upper air, but even in Europe time-tables can be drawn up with due attention to the favourable and unfavourable effect of prevailing winds. The planning of airship routes in particular, must be considered in close connection with this aspect of weather conditions.

To-day, however, the aeroplane may be considered as an "all-weather" craft, save for mist and fog-the enemies of all transport and particularly to that of the air-to which unfortunately England is particularly liable during the winter. Experiments have been carried out on the dispersal of fog, the illumination of aerodromes by fog-piercing lights, and instruments to record the exact position of the aeroplane and its height above the ground, but success has not yet been achieved.

Similar to the problems of flying and landing in mist and fog is that of night flying. Until night flying is practicable, only half the value of the aeroplane's speed is obtainable, since other transport services run continuously day and night. Further, as machines become rapidly obsolete owing to technical progress, it is essential that they should be in use for the greatest number of hours during their life. Much has been done in the lighting and marking of aerodromes and in the equipment of aeroplanes with wireless telephone and direction-finding apparatus.

It may here be mentioned that there are two methods of obtaining the position of aircraft by means of wireless telegraphy, known as direction-finding and position-finding. Direction-finding is effected by means of two coils set at right angles in the aircraft, by means of which the bearing of a transmitting ground station with reference to the aircraft's compass can be taken. When two or more bearings on different ground stations, whose position is known, have been obtained, a "cut" or "fix" of the aircraft is obtained. The position-finding system consists of two or more ground stations fitted with apparatus capable of taking bearings with respect to true north and connected by direct telephone line. The aircraft calls up by wireless one of these stations, requests her position and then makes a series of signals for about half a minute. The stations take the aircraft's bearings, plot its position, and transmit the information to the aircraft. Wireless direction and position-finding, as well as wireless telephony, have on several occasions proved their value to navigation, but in spite of instances of successful night flying, developments have not been such as to render night services practicable.

Marine experience has been a valuable guide, but aerial illumination has entailed many new problems of its own-the distribution of light through very wide angles, the installation of light and powerful lamps in aircraft, the elimination of shadows and the prevention of dazzle, the provision of apparatus to indicate the strength and direction of the wind, and the like.

Very shortly the first organized and equipped night-flying route will be available; that between London and Lympne on the Continental air highway. The Boulogne-Paris section will probably be ready a little later. There will be four lighthouses on the English section, of which two will be automatic, requiring no attention for twelve months at a time. These, and many other, facilities will much assist the progressive establishment of services during the hours of darkness, and will provide valuable data for the establishment of other night-flying routes. There is no real difficulty given a reasonably clear atmosphere.

Organization.

I have mentioned the broad lines on which the organization of the air services was built up before and during the war. We have seen that the initial foundations and framework remained and bore the great systematic structural development which was gradually required. In August, 1914, there were some 240 officers, 1800 men and 200 machines; in November, 1918, 30,000 officers, 170,000 men, and 22,000 machines, all of them better and of a higher performance than those of 1914. Our casualties during the war were about 18,000; air formations had been active in some fifteen theatres of operations; 8,000 enemy machines and 300 observation balloons had been destroyed; some three-quarters of a million photographs taken over hostile country, and 12,000,000 rounds had been fired from the air at ground targets. At Home two organizations had expanded independently from the same seed until, impeding one another's growth, their trunks had joined and a single and improved tree was the result.

This is the only country where a unified air service has been adopted. In war the arrangement was successful. Against its continuance in peace the Army and Navy urge that, with the best of wills, there is a great difference between having an integral branch of a service to work with other services and having to deal with an independent organization, and argue increased cost, duplication, competition and disjointed action. There is no doubt that the liaison of the General, Naval and Air Staffs must be closened, and if co-operation with the senior services was really becoming less satisfactory, a return to the old system should be considered amongst other alternatives, but I do not think that it should be so. It must also be remembered that, although air co-operation is vital to naval and military operations, it is fortunately unlikely that there will be another war for a long time and, meanwhile, the growing essential, independent strategic action would be irretrievably impaired by the reabsorption of the Air into the Army and Navy.

On the other hand, even apart from supply, such a reversion would also cause much duplication, e.g. training. The solution and the correct and logical outcome of the unification of the Air service is the close grouping of the three arms in a Ministry of Defence, and this, even in face of the obvious practical difficulties, should be adopted and co-ordination thus increased step by step. Apart from Supply, some of the services in which this could be effected are the medical, education, chaplains, mobilization stores, transport, works and buildings, accounting, communications, ordnance and national factories. A modified scheme might also be studied in which, under a Ministry of Defence, the Army and Navy each had tactical air units of seconded personnel for artillery co-operation, spotting and reconnaissance, and the Air Ministry dealt with supply, research, initial training and reserves, civil aviation and an independent air force.

One of many good examples of the necessity of co-ordination is afforded by the position of the aircraft supply services at the beginning of the war and their development. We have already seen that there were some eight private firms manufacturing aircraft in a small way and there was practically speaking no engine industry at all. For the Royal Flying Corps, the War Office had relied largely on the Royal Aircraft Factory, and, although the methods of control adopted had many advantages, there was in them a tendency to retard private enterprise and development. The Admiralty, on the other hand, had assisted by dealing almost entirely with firms for Royal Naval Air Service supply. The conditions in France fortunately were very much better than those in this country, and for the first year or two French factories helped us out with both machines and engines. By the end of the war we had the largest and most efficient aircraft industry in the world. There were no less than seventy-six great factories turning out vast numbers of complete aeroplanes, in addition to thirty-three manufacturing complete engines and over 3,000 turning out spares and equipment. Such expansion is not possible within a few weeks, it took a long time to arrive at this position, and it causes one very seriously to think what would have happened had France not been our ally, and points the moral which has been mentioned of the necessity for a thriving aircraft and engine industry in peace. During the war Germany also had a very large number of firms engaged on this work.

The Machine and Engine.

The general differences between service and civil requirements in aircraft fall under the headings of ceiling, load and speed. For service purposes very much higher ceiling and greater climb and speed are required and the design is much affected by the condensed nature of the load. For peace purposes, besides the primary advantage of speed which the air has over other forms of transport, regularity must be ensured and the correct ratio between speed, duration and load-carrying power determined. Great ceiling, man?uvrability and climb are not required.

However great the speed and load, there is no value in air transport, whether for passengers or mails or goods, unless it is safe and also compares favourably from an economic point of view with the older methods. Without these the public cannot be expected to utilize air transport, nor is there any inducement to surrender mails and freight for carriage by air. Every endeavour compatible with economy is made, as far as the equipment of aerodromes and the organization of the routes are concerned, to render air navigation as safe as possible, yet, though both safety and economy of running have been improved, much remains to be done. Safety depends largely on engine reliability, fire prevention and the capacity of the machine to land in small spaces.

Though neither roads nor rails have to be laid and aircraft possess the great advantages of mobility and point to point transit, the initiation and maintenance of an air service is a very complex and costly matter. The utilization of converted war machines is no longer sufficient and those specially designed for commercial work are beginning to make their appearance. Such are the Handley Page W.8, the Vickers, the D.H.18 and 34, and the Bristol 10-seater.

The first two are twin-engine and the last three single-engine machines. Opinions differ as to the relative advantages of the twin and single-engine type. The first and running costs of the single engine are lower, but the twin has greater power and carrying capacity, while most pilots prefer to have a surplus of power over and above that required for normal flight. For these reasons, and because of the psychological effect on insurance companies and on passengers, the twin engine will probably remain in use for large commercial machines, until long-lived and economic engines of more than 500 horse-power are available. On the other hand, where extra power is not required, the twin-engine is not safer than the single-engine machine; no existing twin-engine commercial aeroplane can maintain its height and land safely with only one engine running. Experiments have been made, especially in Germany, on the multi-engined machine with all the engines in the fuselage, but its advantages have so far been counterbalanced by loss of efficiency due to transmission gearing and shaft drives to the propellers and the vibration and weight of the gearing.

High-powered engines are very expensive to run and every effort has therefore to be made by aerodynamic efficiency to carry more useful load with less horse-power. Improvement is being made in this direction; thus the D.H.18 carries eight passengers at 56 horse-power per passenger, the D.H.32 is designed for the same number at 45 horse-power each, and the D.H.34 for ten passengers at 45 horse-power each.

The two best German commercial machines, the Junkers and the Fokker, have a comparatively low horse-power and a low fuel load, but greater attention has been paid to the design of the machines, which are monoplanes with cantilever wings, offering less resistance to the air than our biplanes. One of the most difficult problems is to evolve a high-lift wing which does not impair the aircraft's speed in the air. For commercial machines we must aim at the largest possible commercial load, the smallest possible fuel load and, consequently, an engine which uses fuel economically and, conversely, a lighter fuel. The development of the engine is receiving constant attention, as are also various safety devices, among which may be mentioned those guarding against fire and those varying the lift of wings so as to lower the landing speed and thus decrease the dangers attendant upon forced landings.

In addition to the high initial cost of machines and engines, their maintenance also requires the greatest care. Detailed investigation must be made into all serious accidents. This is now compulsory under the new Air Navigation Act, and the fitness of pilots is ensured by periodical medical examination.

Apart from the weather, the safety of an aircraft depends upon its engine, and perhaps even more upon the installation and accessibility of engines and their adjuncts, such as the petrol, oil, water and ignition systems. During the earlier stages of the war the average life of an engine before complete overhaul was necessary was, of stationary engines, from 50 to 60 hours, and of rotary engines, about 15 hours. To-day these figures stand at 200 hours and upwards and from 50 to 60 hours respectively. For commercial purposes this must be further increased to 300-500 hours as a normal working period.

There are two schools of thought with regard to the efficiency, reliability and the economy of engines. One school advocates using a light power plant per horse-power, run normally at about half its maximum; the other favours a plant of greater weight, more solid construction and greater efficiency, running at nearly its full horse-power. The former is more expensive in primary cost and upkeep, but allows a higher performance and provides reserve horse-power for emergency; the latter is cheaper, but involves a certain risk owing to lack of surplus power. We have hitherto shown a tendency to adopt the former method, the Germans the latter. For commercial purposes a compromise will probably be found to be best.

Apart from the initial outlay on "air stock," the maintenance, overhead, fuel, insurance and depreciation charges are very heavy. These are much affected by such items as simplicity of design, strength against wear and tear, ease of assembly and interchangeability of parts, easily removable engines, increase in durability by the use of metal construction for parts of the machine and the propeller, the elimination of rubber joints, substitution of air for water cooling, facilities for loading and unloading in a commercial machine, simple and efficient navigational instruments and self-starter. Every improvement, however small, will assist to reduce running costs. Then revenue must be increased and the comfort of passengers, as, for instance, ventilation, warmth, luggage capacity and, more than all, a reduction of noise has to be carefully considered or they will not travel a second time by air. An effective engine silencer is at last well on the way. It is obvious what a great advantage this attainment will be both for service and civil purposes. Roughly speaking, a high-powered engine without a silencer is audible at a distance of some seven miles and at a height of 13,000 feet at night time, though these distances are reduced by about a third by day when normal ground noises exist. The bulk of noise is caused by the exhaust, the propeller and mechanical noises in the engine.

I cannot leave this subject without emphasizing the value of research, both abstract and concrete. But, though it is the keystone of progress, its results must largely depend on the amount of flying done. It is clear that for economic reasons new designs can only thoroughly be tried out by commercial use, and therefore again that real progress is dependent on commercial activity.

The advance of civil aviation is bound to be slower than was that of war aviation. But, as war experience improved old and evolved new types, so will peace requirements and experience shape the type and design of aircraft and engine best suited to its purposes. Although a good deal has under the circumstances already been achieved in peace, much remains to be done. Gradually, however, with a modicum of research, improvements in the factors already mentioned and the reduction of initial cost and maintenance expenses, air transport for mails, passengers and goods will take its place as a normal commercial public utility service, and the increased speed of communication will assist in the general development of trade.

Air Services: British, Continental and Imperial.

International civil flying commenced officially on August 26th, 1919, and gradually expanded, both in the United Kingdom and on the Continent, especially during the summer of 1920. France, aided by considerable subsidies, conducted services from Paris to London, Brussels and Strasburg, from Toulouse to Montpelier and across Spain to Casablanca in Morocco; Belgium, from Brussels to London and Paris; Holland, from Amsterdam to London; Germany, in spite of the restrictions placed upon her, entered the field as a competitor and her aircraft flew regularly from Berlin to Copenhagen and Bremen, and from Bremen to Amsterdam. On the American Continent, the United States Post Office ran mail services from New York to Washington, Chicago, and San Francisco, with extensions from Chicago, St. Paul, Minneapolis, and St. Louis.

For reasons which I shall give, there were no internal services in the United Kingdom, but there were four companies operating air lines from London to Paris, one of which held the contract for the carriage of mails. There were also air mail services between London and Brussels and Amsterdam. The mileage flown and the number of passengers and the weight of goods carried were considerable, while the number of letters steadily increased, especially on the Amsterdam service; and an efficiency of 76 per cent., 94 per cent., and 84 per cent. was obtained on the London-Paris, London-Brussels, and London-Amsterdam services respectively.

It must be remembered that these results were obtained without any direct assistance on the part of the State, such as was given by the French Government to air-transport companies in the form of subsidies. British economic policy is traditionally opposed to subsidies, believing that enterprise can be healthily built up on private initiative. Therefore, until 1921 civil aviation had to content itself with the indirect assistance of the State, which consisted mainly in the adjustment of international flying; the laying-out and equipment of aerodromes on the air routes; the provision of wireless communication and meteorological information; research and the collection and issue of general information concerning aviation.

This indirect assistance, however, proved inadequate to maintain the progress achieved during 1920, and therefore the maintenance of air services by means of temporary direct financial assistance had to be arranged.

I have already pointed out the difficulty against which commercial aviation has to contend in regard to the geographical features and position of the United Kingdom. Its comparatively small size, the propinquity of industrial centres, our efficient day and night express railway services, especially those running north and south, lessen the value of aircraft's superior speed and militate against the operation of successful internal air services. Possible exceptions might include amphibian services between London and Dublin, accelerating the delivery of mails five or six hours; between Glasgow and Belfast, where the Clyde and the harbour of Belfast could be used as terminals; or between London and the Channel Islands. I may point out in parenthesis that the development of alighting stations on rivers passing through the centres of towns is important, as a great deal of time is at present wasted in reaching the aerodromes necessarily situated some miles outside large centres of population.

Our immediate opportunities of development near home are therefore afforded by the air services to Paris, Brussels, and Amsterdam; but even here the saving in time is not great, and our position is unfavourable compared to that of the United States, where the Post Office saves two days in the delivery of mails by air between New York and San Francisco; or compared to that of Germany, where Berlin is within a 350-mile radius of Copenhagen, Cologne, Munich, Warsaw, and Vienna, which is itself in an advantageous situation as the junction for a South European system extending to the Balkan States and the Near East.

The ultimate use of the air, however, is not exemplified by a few passengers flying daily between London and the Continent any more than by a few squadrons of fighting craft. In a decade or two overhead transit will become the main factor in the express delivery of passengers, mails, and goods. It is the one means left to the Empire of speeding up world-communication to an extent as yet unrealized. For the price of a battleship a route to Australia could be organized, the value of which would be beyond computation.

The British Empire as a whole offers vast fields for expansion. In Africa, Canada, and Australia are found the great distances suitable to the operation of aircraft, the wide undeveloped areas through which air transport may prove more economic than the construction of railways, and the trans-oceanic routes over which travel by steamship has reached, and in many cases passed, its economic maximum speed. Air transport, careless whether the route be over land or sea, unhampered by foreign frontiers, gives the Empire precisely those essential powers of direct, supple, and speedy intercommunication which ship and rail have already shown us to be vital.

Here again the geographical position of England presents a difficult problem. England is divided from the rest of the Empire by a wide expanse, either of ocean or foreign territory. Egypt, the starting-point for air routes to India, Australia, and South Africa, may be described as the centre of a circle of which England is on the circumference; and it may be some years before an aeroplane can complete the journey between England and Egypt with only Malta as a stopping-place.

The future of long-distance oceanic air routes may depend upon the airship. Lighter-than-air craft, mainly for reasons of cost and vulnerability, did not receive such an impetus from the war as did the aeroplane, but the modern airship has claims for use over distances exceeding 1,000 miles. It can fly by night with even greater ease than by day; fog is no deterrent; engine trouble does not bring it down; and it can take advantage of prevailing winds. It would reduce the sea journey from England to Karachi from 22 to 5 days; from England to Johannesburg from 21 to 7 days; and from England to Perth from 32 to 10? days. Its achievements have already been considerable. In November, 1917, the German L.57 flew from Constantinople to East Africa and back-a distance of 4,000 miles-in 96 hours; in June, 1919, the R.34 flew from East Fortune to Danzig and back in 57 hours; and in July it crossed the Atlantic, was moored out in America for four days, and returned, a total distance of 8,000 miles, in the flying time of 108 hours for the outward and 75 hours for the homeward journey.

Before and during the war Germany gained wide experience in the design, construction, and handling of airships. It is probable that as soon as the peace terms and financial position permit she will begin to establish this form of transport on a commercial basis. In accordance with the Peace Treaty, and the Ultimatum of the London Conference of 1921, the construction of aircraft of all kinds is at present forbidden, but Germany is fostering airship development by the means left at her disposal. Her scientists are probing the constructional problems connected with large airships, while efforts are being made, by financial and other assistance, to maintain her technical staffs and airship bases in existence. At the same time German commercial interests are negotiating with foreign countries with a view to the development of airships abroad, and plans are being discussed for an airship service between Spain and Argentina.

The United States, France, and Italy are all interesting themselves, either financially or constructionally, in the future of airship development.

In Great Britain we have made great strides, particularly in the construction of small types, and our practical air experience in lighter-than-air craft, during the war, is the greatest in the world. With a view to carrying out the experiments necessary further to demonstrate the capacity of airships for commercial long-distance flights, a few months ago the Department of Civil Aviation took over all airship material surplus to service requirements. The main object was to test the practicability and value of mooring airships to a mast. Up to the present, a principal factor militating against the economic operation of airships has been the large and expensive personnel required for handling them on the ground, especially in stormy weather. The mooring-mast experiments have had considerable success and airships have been moored in high winds and over long periods with the assistance of a very small personnel.

The Government has decided, however, though recognizing their potentialities for speeding up communications between the various Dominions and the Mother Country, that the operation of airships cannot be carried out by the State on account of the present financial position.

Recognizing the limitations of Home services and those to the Continent, it was for the purpose of directing attention to the Imperial aspect of civil aviation that the great demonstration flights were organized in which Alcock flew the Atlantic in a Vickers "Vimy," Scott crossed to the United States and back in the R.34, Ross-Smith flew from England to Australia, and van Ryneveld from London to the Cape.

These flights necessitated, too, considerable ground organization in laying out aerodromes, as the following report on one in Africa vividly illustrates: "If aerodromes are left unattended for one year," it says, "practically all the work would have to be undertaken afresh, particularly in Rhodesia. The growth of vegetation is enormous, especially during the rains, and grass will grow to a height of eleven feet in six months; and trees stumped two feet below the surface will throw out suckers and replant themselves within a month after the rains have started.... It is most important that rough drains should be traced.... I have just started planting Doub grass. This grass gives an ideal surface for landing, kills other grasses, and possesses deep interlacing roots which will bind the entire surface of the aerodromes, making it permanent and free from washaways and the formation of sluits."

The demonstration flights, however, showed what could, rather than what should, be done, and what we look for to-day is the inception of practical undertakings, however small, in the various portions of the Empire. The most important of these is the service contemplated between Egypt and India; another instance is afforded by the West Indies, which suffer from the lack of inter-island communications, both for mails and passengers, and this could be partially rectified by an air service employing seaplanes or amphibians for the Leeward and Windward Islands and the Bahamas, and between the Bahamas and the American Continent, where an American company is actually conducting a service. Another project, given up owing to recent disturbances, was one for a flying-boat service on the Nile. Services are also being considered from Malta to Italy, Geraldton to Derby in Western Australia, Sydney to Adelaide and Brisbane, and Melbourne to Hobart in Tasmania. Canadian activity takes the form of work carried out by Government-owned civil machines in connection with forest patrol, photographic survey, exploration, anti-smuggling patrols, etc. It would be a great advantage if railway and steamship companies seriously considered the value of supplementing their services by air.

With regard to Government undertakings on the Imperial air routes, Malta is being equipped with an aerodrome, and a line of wireless stations has been established between Egypt and India, but the organization of this route has been delayed owing to the recent disturbances in the Middle East, and the financial outlay involved in ground organization. As I have said, the air route on which we should first concentrate, over and above the Continental services, is that between Egypt and India. Both strategically and commercially it is the most important in the Imperial system; it is a step towards Australia; it offers possibilities of the greatest volume of traffic; it should be much simpler to control than many international routes, which inevitably have many complications; weather conditions are not unfavourable; and the time taken for the journey by sea would be reduced by about one-half. If the shortcomings in point of distance of the continental routes in reaping the full advantages of travel by air, and the importance of the best possible communications for the Empire, are recognized, it is essential that a practical form of assistance should be given in the near future to the conduct of weekly or even bi-weekly services each way between Cairo and Karachi. Although it will not be a commercial proposition for some time, the Egypt-Karachi route, shortening as it will the delivery of mails between England and India by two-thirds, and England and Australia by one-third, offers greater results than the various other schemes at present contemplated. There are, however, certain considerations which will have to be weighed before the immense amount of work necessary to its initiation as a commercial air route is begun. The French, for instance, hope to push a trunk air route to India via Constantinople, and this line has the advantage of avoiding a long sea and desert crossing. On the other hand, it will be a very difficult matter to negotiate the mountains of Anatolia.

If enterprises of this kind are successfully started, if each of our self-governing Dominions and Colonies encourages civil aviation within its own territory, and develops the air-sense of its people, each portion of the Empire, by a process of natural expansion, and by the gradual extension of local air lines to merge with those from other portions of the Empire, will assist in eventually forming a continuous chain of inter-Imperial air communication. Such a process of internal development, supported by close co-operation between the States of the Imperial Commonwealth, is the best method of obtaining rapidity of air intercommunication and a system of Imperial air bases necessary to the strategic security of the Empire.

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CONCLUSION

Within the necessarily narrow limits of this survey there has been traced the history of aviation from the earliest days; the tremendous impetus given to it by the war has been described, during the course of which not only did air co-operation become essential to the Navy and Army, but the importance of the Air Force as a separate arm, with its own strategic action, steadily grew; the increasing preponderance which aerial warfare will have in the future, and the horrors which it may bring, have been touched upon; and the possibilities of civil aviation in peace and war have been outlined.

The conclusion has been reached that we cannot dispense with aviation, even if we would. We must consider it as a whole and lay down the broad principles on which it should be developed. The air (I write as one who during the last months of the war held the post of Chief of the Air Staff) materially helped, if it did not actually win, the fight. It has greatly complicated and increased the problems of defence. In future its influence on these problems will be still greater. The air has no boundaries. Great Britain and the Empire are no longer protected by the seas. A correct assessment of their needs will entail a growing ratio of air force to Army and Navy, and air power will in itself depend on the development of civil aviation.

But though air action may be expected with justice to grow in proportion to that of the Army and Navy, and will certainly absorb certain functions of both, it would be unwise, at this early stage of development, for air forces to attempt too much at a time-such as, for instance, to garrison geographically unsuitable countries.

A certain amount of reliance could also be placed on civil machines temporarily borrowed for purely policing measures in uncivilized countries, or for the assistance of Government during civil disturbances; and for such purposes it should not be difficult to devise a scheme, especially when the State exercises a measure of control through the grant of subsidies, for the obligatory enrolment of civil commercial pilots in the reserve, and for periodical refresher courses for pilots, who are not actually in the service of companies, at civil aerodromes. Such systems are in force in France and Canada. In the event of war the independent striking air force could thus count upon a large proportion of civil reserve pilots and machines.

Air, allied to chemistry and the submarine, will be a difficult combination to withstand. The more its potential terrors are grasped, the less likely is war to be loosed upon the world, and it cannot be realized too clearly how much more easily than any other instrument of warfare aircraft and gas can be cheaply and secretly prepared by a would-be belligerent. Meanwhile, if civil aviation can be built up as a productive organization to a position relative to that held by our mercantile marine, we must understand that it will ensure air supremacy better than a large unproductive outlay on armaments. And I am convinced that, with public support, this can, and will, be done. Others will do it if we do not. But air power, although drawing its vitality from the expansion of air commerce and the growth of the civil aircraft industry, must at the same time rely upon the nucleus of a highly trained and technical air force. Service aviation must be the spearhead, civil aviation the shaft, of our air effort.

The present isolation of England in terms of air from the rest of the Empire, and the geographical conditions already described, certainly render the national expansion of aviation, both external and internal, a difficult problem. It is clear that for this reason it must rather develop on an Imperial basis. The Dominions have already started valuable civil air work and have appointed Air Boards. Whatever the political settlement of Egypt may be, it is important that our air interests at this "hub" of Imperial aviation should be safeguarded. Air communication between the various portions of the Empire may prove of inestimable value in a future world war, and Dominion air forces may be able quickly to concentrate against enemy territory which is out of the range of aircraft operating from home. We have seen the value of aircraft operating from land bases for naval patrol, anti-submarine action, and direct attack on enemy shipping. With the increasing radius of action of seaplanes and other naval aircraft, the Army and Navy may be relieved of certain of their duties in coast defence and in protecting Imperial trade routes. For these reasons, aircraft bases are required throughout the Empire, and it is the commercial development of aviation which is the best means of ensuring their establishment. It will be for the Imperial authorities, while attending to local conditions and requirements, to co-ordinate as far as possible the air effort of the Empire, so that in peace communications may be developed and in the event of war its full power may rapidly be utilized on a co-operative basis.

Civil aviation is not, however, merely a method of amplifying service air power. It has a vast potential value of its own. Communications shape human destinies. The evolution of our civilization bears strongly the marks of the systems which at various stages have made the intercourse of men and ideas possible. Its history is one of endeavour to extend the limits imposed upon human living and mobility in each of the great phases through which it has passed.

There was the phase of the coracle and the roller-wheeled vehicle, stretching back into the roadless mists of unrecorded time; of roads which gradually linked the important areas of the Roman Empire; of inland and coastal waterways; of ocean traffic, and its huge advance with the discovery of steam-power, which brought England to the fore.

With each phase the world shrinks smaller and the mists of the unknown recede. The development of human mobility is the greatest marvel of the present age. We can hardly realize that it was only the other day, as these things go-in 1819, just a hundred years before the same feat was accomplished by air-that the first sailing ship fitted with auxiliary steam (and not until 1828 that a real steamship) crossed the Atlantic.

Strain and competition are increasing. Trains vie with ships; motor transport with trains. Telephones, wireless, cables, and flying are speeding up communications to a degree undreamed of a few years ago. If the air is to be a prime factor in the world-phase to come, how will the British Empire be affected? Stretching from Great Britain to Australia and the Pacific Ocean, the Empire depends more than any other political and commercial organization on the most modern and speedy communications, and as each of its portions assumes greater responsibility there is greater need for co-operation, the distribution of information, and the personal contact of statesmen and business men. "The old order changeth, yielding place to new"; and in communications the new order is air transport.

Equally important is the international aspect. To-day we are deeply concerned with the maintenance of peace, and this can be achieved, not so much by the action of Governments, or the efforts of the League of Nations, as by the personal association of individuals of one nation with those of another, and an increasing recognition of common interests. I conceive that civil aviation, by reducing the time factor of intercommunication, will tend to bring peoples into closer touch with each other and will make for mutual understanding. The Peace Treaty provided for an Air Convention for the international control of civil aviation. The Convention has been signed by all the Allied nations which took part in the war, and I hope other countries will shortly be included. As soon as the Convention has been ratified, the International Commission of Air Navigation will be established, and for the first time the world will see the international control of a great transport service. I believe this will prove an important practical step towards international co-operation and goodwill.

We have no excuse for ignorance of the effects of Imperial and international co-operation. The war gave us an example of what the British Empire can do, provided its combined knowledge and effort is brought to bear for one great purpose; and in no respect was this better exemplified than in the utilization and scientific development of aviation. The world-position of the Empire as a whole is still the best. Commerce and communications are its bonds, and, if we are so determined, it is in our power to shape the destinies of the future.

A definite advance has been made since the Armistice and, if all goes well, a very much greater one will be made during the next two or three years, and in ten years mercantile air services will be operating on a self-supporting basis. The science and concentration employed in the war must be made to serve the requirements of peace. Readiness for, and success in, war are vital when war is unavoidable, but in peace it is civil and commercial activity which is vital.

As in its infancy it seemed incredible to those responsible for the direction of the older services that the air would be their most valuable partner; as, during the war, they grudged its logical development to strike widely where they could not reach, and tried to tether it closely to them, so now in peace the air is struggling to attain the apotheosis of communication.

In the phase of world commerce of which we are on the threshold, science, brain-power, energy, and faith must, and increasingly will, be harnessed to the work of perfecting air communication so that human mobility can be increased, knowledge interchanged, and the fruits of production distributed throughout the world.

As a soldier I have of course dwelt on the possibility of war in the future and of the part which aviation would play in it, but it would be a great mistake-though I think that mistake is constantly made-to suppose that soldiers look forward with equanimity to the prospect of war. On the contrary, soldiers, more even than civilians, if this be possible, realize the horrors of war and recognize that the great task rests upon the statesmen of all nations, and upon humanity itself, of taking whatever steps can be taken to prevent its recurrence.

We may at least assume that another great war will not be allowed in our generation. But war, in spite of its horrors, in spite of its bereavements, is only too quickly forgotten. A comparatively few years, and those who have passed through its fire are no more. New wealth is created; new antagonisms arise; and a new generation remembers only the romantic stories and the martial deeds of its fathers, or, more fatally, organizes itself to avenge defeat. Then, once again, forgetful of the terrible lesson we have learned, the great nations of the world may unsheathe the sword as the only solution to their problems. Our only hope lies in using the ensuing years to educate mankind to the principle that war brings misery and impoverishment to all engaged in it, that in the final victory it is not a question of which is left the strongest, but which is the least exhausted, and that national are as susceptible as personal differences to discussion and arbitration. Above all, let us guard against the old mistake of competitive armaments. There is no reason, for instance, why, because France, our friend and ally, is adopting a policy of air armaments, we should blindly pile up aeroplane against aeroplane, pilot against pilot, and thus provoke mutual suspicion.

The possibility of war remains, however, and I wish in conclusion to emphasize the fact that in my belief the security of this country in the event of war will depend upon our strength in the air. The development of the offensive powers of aviation have already destroyed "the silver streak" on which we relied in the past. When we remember that it is less than twenty years since the first successful aeroplane was flown, when we recall the almost miraculous development of the fighting powers of aircraft during the four and a half years of war, and also the further developments which were on the point of being utilized when the war ended, it seems certain that from the point of view of war Britain has ceased to be an island. The "silver streak" would have been little protection but for our naval supremacy, and in the future our security will depend as much upon superiority in the air as it has depended in the past upon our superiority at sea. And this superiority in the air can only be attained in the same way in which we secured our supremacy at sea. That supremacy was not really gained by developing great navies. It was gained by our mercantile marine, which made the great navies possible. Our future security can only be gained by the development of commercial aviation.

Printed in Great Britain by Butler & Tanner, Frome and London.

Transcriber's Note: Minor typographical errors have been corrected without note. Variant spellings, e.g. Frankfort and Frankfurt, remain as printed. Significant amendments have been listed below: Page 67, 'Poperighe' amended to Poperinghe.

Page 117, 'Junker' amended to Junkers.