EMPLOYMENT AND TACTICS OF AIRCRAFT IN NAVAL WARFARE
By Commander John P. Jackson, U. S. Navy
The Place of Aircraft in the Military System
1. Throughout the Great War and up to the present time, ideas regarding the strategic and tactical employment of air forces in co-operation with land and naval forces, and as to the coordination of the operations of the many different types of aircraft amongst each other, can hardly be said to have crystallized. Aircraft, much as they were used in the Great War, were employed upon more or less detached raids, attacks, scouting and other operations,—sometimes alone, and sometimes in conjunction with land and naval forces,—and the relative proportion of aircraft to land, and naval forces, and the proportion of various types of the craft themselves to constitute a well balanced air force, is still to be determined.
2. The exact place which should be occupied by the air force as a whole in the great military scheme in which the land and naval forces have definite and established places, determined through long years of study and practical experience, has not as yet been settled. The very question as to whether the air force should be under a separate administration or be a part of the army and navy, is at this very moment unsettled and under discussion in the principal countries of the world.
3. The question has been a very live one in the United States, and great pressure and much propaganda have been brought to bear from certain sources to take the air forces away from the army and navy and consolidate them into a separate co-ordinate department. The arguments for and against such a policy are strong and many, and an exhaustive consideration of them would call for a voluminous discussion which would expand this paper far beyond reasonable bounds. I shall content myself therefore with quotations from expressions of opinion of one officer from each of our services. On January 12, 1921, General Pershing, in answer to a letter, expressed himself in part as follows:
Military forces can never be efficiently trained or operated without an air force.
An air force, acting independently, can of its own account neither win a war at the present time, nor, so far as we can tell, at any time in the future.
An air force by itself can not obtain a decision against forces on the ground.
A military air force is an essential combat branch and should form an integral part of the army.
If success is to be expected, the military air force must be controlled in the same way, understand the same discipline and act in accordance with the army command under precisely the same condition as other combat arms.
An air force, as well as all other branches of the military organization must fully understand its exact functions in working with other branches, must know the needs of other branches, be in full sympathy with them, think in the same military atmosphere, and have the same esprit de corps in order that effective battle control may be established.
No such force can realize the above conditions unless it be an integral part of the command not only during battle but also during the entire period of doctrinal training.
To realize these conditions the different arms of the service must live together and train together.
An air force should be established as a separate arm of the service, coordinate with, the infantry, cavalry and artillery.
The air force should not be established as a combatant force distinct from the army or navy.
4. By substituting the words "naval" for "military," and "navy" for "army" in the above quotation, and where he speaks of "infantry", "cavalry" and "artillery" by substituting the various branches of the naval service, General Pershing's opinion applies with as much force to the navy as to the army.
5. Certain officers of the U.S. Navy are as strongly opposed to having its air force removed from its control and jurisdiction, as is shown from the following quotation of an officer of the aviation section of the navy:
Aircraft considered from a purely naval standpoint will be of use in helping to gain command and to exercise command of the sea, but they never can be the determining factor. The big gun and large surface craft are the controlling factors in gaining command. Such craft (capital ships) combine mobility, protection and armament to the greatest extent. Supported by proper types and a train they can operate for long periods in an enemy area securing permanent local command of this area.
Aircraft possess great mobility but can not occupy an area permanently unless close to a base defended by the guns of ships, or the artillery or infantry of an army. Air control, while specially applicable to breaking up the control of areas either ashore or at sea, is less applicable to keeping permanent control, and, therefore, must base behind the other arms and is best used as an adjunct to the other arms.
Such being the case and military operations necessitating a unified command in which surface craft are maintained in areas supported by variety of arms—destroyers, submarines, aircraft, etc., it is obvious that aircraft at sea must be a part of the operating forces at the disposal of the commander-in-chief and the personnel and the type must be adapted and trained to meet sea conditions.
The seaman considers he has a special training and profession in which long training, drill and experience are required through a life time career. Conversely he has not assumed that he can tell other professions military or civil what their methods, tactics or strategy should be. He does not desire to encroach upon the province of the soldier or civilian as he assumes that each has a special profession. The use of a new arm such as aircraft at sea needs special types and adapting for application to the seaman's problem in securing and exercising control of the sea. Seamen and naval commanders familiar with naval practice, strategy and tactics are necessary in aircraft for naval purposes to fit in properly this arm with the other arms in developing mobile sea power.
I doubt whether in the future any Admiral on the navy list will care or dare to guarantee the national defense at sea if the naval air forces are detailed from another corps in which the personnel are dependent for development technically and professionally and for pay and promotion upon such other corps foreign to the navy, and in which the material is dependent upon the decision of officials outside of the service. This responsibility for the national defense at sea is carried by officers of the navy and it cannot be shifted.
6. In addition to the military reasons against a separate air force, there are many considerations in the development of civil and commercial aviation which indicate that it is much more advantageous to have separate government organizations in control of the air forces of the nation than to have these consolidated into one. These arguments are even more voluminous than the military ones, and no attempt can be made to present them here.
The Capabilities of Aircraft
7. War as conducted on land and sea has, through centuries of practice and experience, laid down certain well known and immutable principles. In other words a doctrine for the conduct of war on land and sea has come to be recognized. The advent of aircraft has introduced elements so different from those hitherto employed, and whose capabilities are as yet so little appreciated, that an entirely new field has suddenly been opened up for the conduct of hostile operations, with possibilities which may well revolutionize modern warfare. As an example of the confusion of thought which at present exists, may be taken the present controversy between the aircraft and the battleship, which is raging throughout the world. Extreme adherents of the aircraft claim that the recent experiments in the United States have unconditionally rendered the most modern battleship obsolete. The advocates of the battleship, on the other hand, claim that its position as the backbone of a naval force is unshaken, and that a new weapon has merely been introduced, which must be guarded against.
8. The truth of course lies as usual between the two extreme views. It is far from proven that the battleship is obsolete, but on the other hand there is no question that a most serious menace to its existence has been brought into being. How far then is a nation justified in depending upon battleships for its defense? And to what extent should it develop its air force, not only as a menace to the land and naval forces of an enemy, but also to co-operate with its land and naval forces in their own defense and the defense of the nation itself?
9. This is a major question of military policy and strategy, and its solution depends upon the development of a sound doctrine for the employment of air forces. Doctrine is merely the reduction to tangible form of the principles which govern action. To develop a doctrine for the air force therefore, we must investigate the capabilities of aircraft in relation to the recognized principles of warfare. And it is here that the difficulty arises. The capabilities of aircraft are so indeterminate on account of the rapid strides in improvement continually in progress, that it is practically impossible to say at the present moment what aircraft can or cannot accomplish, and whether they can even accomplish under war conditions what they are well known to be capable of in suitable weather and in time of peace.
10. As an example, it has been proven by the recent experiments that selected types of aircraft, tuned up for the occasion, and carrying the. largest bombs yet constructed, can under ideal weather conditions sink an old type of battleship, stationary and defenseless, not more than 100 miles from the aircraft base—if they drop their bombs exactly where they desire. But alter any of these conditions and what can the aircraft do? Can it sink a modern battleship, specially constructed to resist air attacks, maneuvering at high speed in any kind of weather, and defended by efficient anti-aircraft batteries and numerous fighting planes of its own?
11. We have considered the ideal condition for the aircraft and the ideal condition for the battleship, and in each case can be reasonably sure of the answer. But what will be the result when the conditions are neither ideal for one side nor the other? Ideal conditions for any particular weapon seldom exists in war, and we must rate the value of any weapon upon its practical ability to function successfully under actual war conditions. The battleship will run a risk when conditions are not favorable to its defense; and the aircraft, by seizing the opportunity when most of the advantages are in its favor, may be able to make a successful attack. It is under these varying probable conditions that our knowledge of what can or cannot be done is so meager, and at the present moment we cannot do much more than conjecture. However, in the present state of rivalry between nations (and no nation is without its own particular rival), one cannot afford to await the complete solution of every unsolved military problem before deciding what kind of a military force to construct. One must make the best possible conjecture as to the probable value of various means of defense, and then construct these in accordance with the most probable conclusions reached.
12. To form some idea, then, as to how much one should depend upon an air force, and what should be its size and characteristics, we must consider, with the best information available, the capabilities of modern aircraft, and estimate how much these capabilities will be increased at the present rate of progress. We must then study all types of aircraft which exist at present, their capabilities as shown by past performances, and the lines of development along which progress is leading. We can thus arrive at some conclusions as to what we may reasonably expect our air force to accomplish, and form a plan for the employment of the air force in war. This should include co-operation with land and naval forces, and co-ordination of the different types of aircraft themselves in the various operations of war. In this way a doctrine is formed for the conduct of air operations, which will form the basis upon which to construct our air forces. We can then determine what size air force we shall need, and the relative proportion of the various types to produce a well balanced force.
Types of Aircraft
13. A complete study of aircraft would of course fill volumes, and the mass of technical detail would end by obscuring the issue. Such a study is of course not contemplated here. The principal types will merely be enumerated, with their characteristics, advantages, and disadvantages in brief; and their capabilities will be assumed from their best known performances, to give us a basis upon which to formulate a tentative doctrine for the employment of aircraft in war, and to devise a system of aerial tactics.
14. Aircraft are divided into two main classes: Lighter than air, and heavier than air. Lighter than air craft are divided into dirigibles, free balloons, and captive balloons, of which latter type the kite is the most efficient for war purposes. Dirigibles are further divided into rigid, semi-rigid and non-rigid types and are constructed in innumerable sizes, from the Baby Blimp to the Zeppelin. They all have self-contained motive power and are capable of being controlled in speed, elevation and direction. Free balloons have no motive power of their own, but are capable of movement with the wind. They can be controlled in elevation but not in direction. Captive balloons have no motive power, and are incapable of movement, except that they can be controlled in elevation by power outside of themselves.
15. The largest dirigibles must above all have endurance and ability to keep the air under adverse conditions of weather. Their speed and climbing power are moderate. Smaller dirigibles have these qualities correspondingly decreased. Free balloons are of no practical use in war. Kite and other captive balloons are used for observation purposes and control of gunfire. They must offer a reasonably good platform and be capable of being quickly hauled down.
16. Dirigibles can operate only from the shore, and therefore cannot be counted on for reliable use with the fleet. This was demonstrated at the Battle of Jutland by the failure of the German Zeppelins, in spite of the proximity to their bases at which the action took place. Kite balloons can be used advantageously from the decks of large ships, for observation and spotting purposes, and it would seem that at least one ship in each division of capital ships should be equipped to carry them.
17. Heavier than air craft are almost infinitive in type, size, and characteristics, but can be divided according to their uses into a relatively small number of principal types. They can best be considered under the uses for which they are designed.
Methods of Employment
18. The employment of aircraft in war can be grouped into the following main divisions:
1. Securing command of the air.
2. Scouting, reconnaissance, and patrol.
(a) Photography.
3. Fire control, observation, and spotting.
4. Protection of the fleet.
(a) Smoke screens.
5. Attack on enemy surface and sub-surface craft.
(a) Illumination.
(b) Bombs, torpedoes, and guns.
(c) Gas attacks.
6. Escort of convoys.
(a) Submarine and mine search.
7. Dispatch carrying.
8. Transportation.
9. Evacuation of the wounded.
10. Control of operations from the air.
19. Of these the first is most important, just as it is with a fleet on the sea, and its successful accomplishment facilitates all of the other duties of aircraft listed below.
Aeroplanes with the Fleet
20. There should be at least one large plane carrier with the main body and one with the principal scouting force. In addition every large ship—that is, battleships, battle cruisers and scouts—should carry one or two planes. The ideal would be of course to have enough planes on warships and plane carriers to secure indisputable control of the air, and this should be the objective striven for. Since the number of planes which can be carried on regular warships is necessarily restricted, the number of plane carriers must be increased to attain the desired end. On cruisers which carry but one plane, this should be a scouting plane. In capital ships which carry two planes, one should be an observation plane and one a combined fighter and light bomber.
21. For practical operations the proportion of types depends naturally upon the enemy's air force, and upon the actual conditions it is expected to encounter. In general, there must be enough pursuit or fighting planes to control the air in any probable situation which may arise. Each capital ship must carry its own observation or spotting plane. There must be enough scouts to keep informed of the enemy's movements. Then, the rest of the carrying space available can be given up to bombing and torpedo planes.
Auxiliary Character of the Air Force
22. Before considering the tactics of aircraft, it is desired to invite attention to a fact regarding the character of air forces, which it will be well to bear in mind. An air force at the present time is essentially an auxiliary force. As General Pershing states, it cannot, acting independently and on its own account, either win a war at the present time, or obtain a decision against forces on the ground. The same may be said of the sea. Securing command of the air is thus an operation of a somewhat different character from securing command of the sea. At the present time it but facilitates the accomplishment of the preliminary operations necessary and leading up to the securing of the command of the sea. In a sea campaign, therefore, we must consider the air forces merely as any other part of the auxiliary or minor forces, such as destroyers and submarines, scouting vessels, etc.; and in no case must we invest them with the attributes of a main fighting force; which attributes the battle fleet, and it alone, possesses.
Aircraft Regarded as Projectiles
23. We might even go a step further, and instead of classifying aircraft as a part of the auxiliary forces, class them as long range projectiles. Since the range and endurance of aircraft is not sufficient to permit them to control the command of any extensive area of sea or land by themselves, they must have a base close at hand from which to operate and to which to return when their endurance is exhausted. The base may be an air station on shore or a plane carrier at sea. The air station on shore is thus analogous to a battery of high powered long range guns, and the plane carrier is analogous to the capital ship. Each is an establishment for the hurling of projectiles against the enemy.
24. Considering aircraft in this light their effect upon the tactics of warfare can be estimated. The aeroplane is nothing more than a projectile of much greater range than the shell from a heavy gun, or the torpedo; capable of being aimed and otherwise controlled during its flight, and if not destroyed, of returning to its base after its attack; but also susceptible of being intercepted and stopped during its flight before it reaches its target. The obvious tactical result of the great range of aircraft considered as projectiles is to increase tremendously the battle range between opposing forces. An air station ashore or a plane carrier at sea protected by other forces to the best possible degree from every known kind of an attack, can launch its projectiles (aircraft) against an enemy distant many times the range of visibility.
25. The controllability, however, of the aircraft projectile during flight, and its susceptibility of being intercepted, introduce new tactical elements in the employment of this method of striking the enemy. Unlike the shell and the torpedo which after leaving the gun and the tube proceed automatically toward the target unguided by human skill after the initial aim and adjustments have been made, the aircraft remains under the control of human intelligence until it delivers its attack, is destroyed, or driven off. The enemy also sends out similar weapons under the same kind of control to prevent it from accomplishing its mission. What is really a battle of projectiles then ensues to determine whether the target shall be reached or not.
Plane Carriers as Capital Ships
26. The greatly enhanced importance of the plane carrier becomes obvious, viewed however not as an element designed solely to facilitate the acquisition of the command of the air, but rather as a capital ship of the sea fleet carrying projectiles for attacking the enemy's main force far outranging those of the present battleship. In other words, aerial development will have the effect of adding a new type of capital ship to the sea fleet. In order to use this type the command of the sea is still of vital importance.
27. From its very nature and the requirements of the aircraft which it is to launch as projectiles, this new type of ship—the plane carrier—will not be able to defend itself against the attack of hostile battleships. Just as a battery of heavy artillery on shore must be protected against capture by the employment of light artillery, machine guns, and trench mortars, so must the plane carrier at sea be protected from enemy surface craft by battleships and other sea types.
28. The ideal of course would be to combine the plane carrier and the battleship into one all powerful vessel, with the ability to gain command of both sea and air. As this is obviously impossible we must recognize the advent of the new type of capital ship without discarding the old, and the backbone of the modern fleet will consist of both types—the plane carrier and the battleship. Just as the battleship was formerly the target for attacks by destroyers and submarines, so now the plane carrier and battleship will be subject to these attacks and, in addition, to the attacks of aircraft. It cannot be seen from present accomplishments, that the broad principles of naval warfare have been upset, but merely that the tactics have been altered by the introduction of a projectile of very much greater range and controllability, and the opening up of the third dimension to hostile operations.
29. The recent experiments against the old Alabama of the American navy show up much that is startling in the possibilities of poisonous gases, flares, and smoke screens launched by aircraft against surface craft; but it must be remembered that these were conducted against an inert target; just as the former experiments against the old German ships were. Undoubtedly the side which gains complete command of the air can inflict terrific punishment upon its adversary, but the same may be said of the side which formerly had gained undisputed command of the sea. In the future, command of the sea and command of the air must go hand in hand, arid until aircraft as stable and of as great endurance as seacraft are developed, it is difficult to see how either can be gained or maintained without the presence of a sea fleet.
30. Furthermore, even if it is granted that aircraft can safely protect the entire coast and hold seacraft at a distance of 200 miles therefrom, as has been claimed, this is purely a defensive measure. To win, offensive tactics must be pursued. How can aircraft by themselves carry the war to the enemy's coasts, maybe thousands of miles away? It is inconceivable that they can, without the escort and support of a sea fleet. This fleet must be of the most powerful and include battleships, or it can be destroyed if the enemy has more powerful ships to send against it. In any way that the subject is approached, it is impossible to get away from the absolute need of the battleship as the backbone and main support of all other types of craft designed to fight on, under, or over the sea.
Nature and Control of the Air
31. Securing command of the air, then, is an operation analogous to an action between the light surface forces of opposing fleets to get local command of such area as to permit of driving home a reconnaissance, of carrying on distant scouting, or to facilitate minor attacks upon the enemy main force. It is for these same reasons that command of the air is sought. The advent of aircraft has merely opened up another plane for the conduct of hostile operations, just as the development of submarines did. And no more than did the submarine, can the aircraft take the power of decision away from the heavy fighting units of the surface fleet. When a submarine battleship is developed, the power of decision may pass to it from the surface battleship. So also when an aircraft of equal power, endurance and stability to the surface battleship is developed, the obtaining of a decision may be transferred from the surface of the land and sea to the air. Such an event is for the far distant future, if ever; and until that time, we are not justified in considering air forces as anything more than auxiliaries and adjuncts to the fighting forces of land and sea.
32. Thus far the mission of aircraft is to assist the naval and military forces in the accomplishment of their missions rather than the accomplishment of any major operations of their own. With this clearly in mind we are in position to develop the tactical use of aircraft and show how they can be of the greatest use in the conduct of war. The first use to which aircraft would probably be put in war would be scouting and reconnaissance. But just as the light surface forces must secure the local command of a definite sea area in order to do effective scouting and drive home their reconnaissances, so must the aircraft secure at least a temporary command of the air in the locality where their scouting operations will take place. We may then well begin with a consideration of the first of the enumerated uses of aircraft in war, not only because it is the most important, but also because at least to a limited degree it is the first use to which they will be put.
Securing Command of the Air
33. To secure command of the air, the enemy's aircraft must be destroyed or driven out of the air. To accomplish this an adequate number of planes of high speed, great offensive power against any type of enemy aircraft which they may encounter, and comparative invulnerability, in whatever manner this is secured, must be employed.
34. These requirements resulted in the development during and since the Great War, of a type of plane known as the pursuit or fighting plane. Its general characteristics are briefly as follows. It must have speed from 120 to 160 miles per hour, and in the future probably these speeds must be increased. It must carry as many weapons as possible to inflict damage upon the enemy. At present two to four machine guns are carried, the number being limited by size and other considerations necessary to obtain the remaining requirements. There is at present no need for more or larger guns, since its antagonists are entirely vulnerable to the present weapons. As defensive qualities are improved, however, the near future may well require fighting planes to carry three-inch guns or even larger. To secure an advantageous position from which to attack it must have great climbing ability. In the past this has been between 9,000 to 12,500 feet in ten minutes. It must be able to out climb any other type of machine which it may encounter. For the same reason, and to attain invulnerability through its power to elude, it must be a quick maneuverer. This sets a limit to its size, which in turn offers a smaller target to the enemy. The spread of wings thus usually runs from thirty to forty feet, which makes it one of the smallest machines used for war purposes. It carries a crew of one or two men, but possible future development of its armament may require more.
35. As to the broad tactics of fighting planes, they should be sent out in large numbers upon arriving in a region where it is expected to encounter hostile aircraft. If these latter are actually in sight, the fighting planes should be sent out in advance of any other type to drive them away. Otherwise, they should follow up the scouting planes, whose radius of action is much greater, and be in position to support them if they are driven in. Their mission is essentially to secure command of the air and to support and protect all other types of aircraft and surface craft as well, against the attack of hostile aircraft. Their tactics in co-operation with other types will be considered in connection with the uses to which these other types are put.
36. Their combat tactics have heretofore varied almost with the whim of the individual pilots. Each ace and famous birdman of the recent war had his own particular style and method of fighting. It is about time that some approved principles for combat in the air became crystallized. In general the tactics consisted in maneuvering to bring the opponent under a quick intense burst of machine gun fire while keeping out of the arc of his fire. The maneuvers obviously depend upon the number and type of guns in the opposing aircraft, and the method of mounting these. The propeller is the greatest factor tending to limit the arc of fire. Guns cannot fire through the propeller unless they are synchronized with it or fire through the propeller shaft. In these cases the guns are fixed and can only be aimed by pointing the craft itself, which necessarily greatly hampers its possible maneuvers.
37. During the recent war, fighting planes carried only one or two small guns and the methods of mounting these were very much restricted. This will be referred to later. With development, particularly in the size of aeroplanes and in the various methods devised to eliminate dead angles, it is pretty certain that in the future, fighting aircraft will have guns so mounted as to cover all arcs. The problem will be to devise a system of mounting capable of delivering the maximum fire in all directions, just as the center line turret system does for ships. Until aeroplanes are armored, there would seem to be no reason for carrying anything larger than machine guns for use against other aircraft; but recent developments indicate the feasibility of mounting cannon up to as large as three-inch. For the present these would only be used against ships or ground forces, and will be referred to later.
Scouting, Reconnaissance, and Patrol
38. The first use to which aircraft were put in war was scouting and this still remains one of the most important. Aircraft are the eyes of the fleet to a much greater extent than surface scouting craft can be, and are used in two ways. First, small short-range machines flown from the decks of scouting vessels themselves to increase the scouting area covered by the latter; and second, large long-range machines flown from specially constructed carriers, or from bases on shore, for independent distant scouting and reconnaissance.
39. When flown from scouting vessels planes are used either to cover the area between the vessels of a scouting line, thus permitting the distance between these to be increased, and extending the area searched laterally; or they can be sent out at daylight and before dark to cover additional areas backward and forward in the direction of the course of the scouting vessel, thus increasing the area searched along the axis of the search. The range of vision of aircraft varies of course widely according to atmospheric conditions, as well as does their visibility from other craft. Cases are known of their having seen ships at sea clearly for thirty miles, and the smoke of large cities at ninety miles; whereas at times while spotting from directly over a target, they could not see the firing ship at all due to peculiar haze conditions, although the latter could see the target.
40. Most of these atmospheric conditions affect scouting vessels as well as aircraft, and the conduct of a search must be altered to suit them. Often there is a haze at moderate altitudes whereas there is none on the surface of the sea and vice versa, and advantage must be taken of the best existing visibility. The visibility of aircraft from other craft depends as much upon the light conditions, direction of the sun, background, etc., as upon the haziness of the atmosphere. Since scouting aircraft should if possible keep themselves concealed from the enemy, advantage may be taken by a skillful pilot of different combinations of weather conditions to see without being seen.
41. As to the tactics of small scouting planes, there is not much to be said. They must of course elude or retire before fighting planes and other types more powerful than themselves. The chief care should be to scout the assigned areas thoroughly, leaving no unsearched spots; and to this end as well as in order to be able to pick up the mother ships again, the greatest attention must be paid to their navigation. For long distance independent scouting, aircraft are far superior under good weather conditions to surface vessels, on account of their greater speed and vision, which enables them to cover an area many times larger than a surface vessel can do in the same time. Sea planes are in existence with a radius of 1,200 miles. With a speed of sixty miles an hour or more, it is easy to see what immense areas can be covered in a few hours, which it would take surface vessels days to get over in addition to the complications introduced by periods of darkness. Dirigibles are especially adapted to this work on account of their very great radius of action. But they are visible long distances, are extremely vulnerable, and cannot be employed in the face of effective aerial opposition, at least not until the use of helium or some other non-inflammable substitute for hydrogen is found practicable, and some form of protection against gunfire developed. Large dirigibles, also, can only be employed within radius of their bases, and hence are unavailable to a fleet on a long distance oversea expedition until some sort of an operating base for them is captured. They are moreover very liable to be disabled by adverse weather conditions.
42. Of course in all distant scouting the difficulties of aerial navigation must be thoroughly appreciated. On account of air currents whose force and direction is unknown and which differ at different altitudes, dead reckoning is of practically no use. Astronomical observations are difficult to take and untrustworthy, due to the inaccuracy of estimating the height of the eye, and the discomfort and exposure of the observer. Navigation by landmarks, akin to coastal navigation, is the only thoroughly reliable method, and of course this is not available when out of sight of land.
43. In general, the same methods of search available to surface craft are at the disposal of aircraft ; but due to the difficulties of navigation mentioned above, complicated schemes involving the various methods of the retiring search curve should not be attempted. Only the simplest forms of search, involving direct courses, should be tried; and if not in sight of land, the position should be checked as frequently as possible by sighting surface vessels from whom accurate positions can be obtained by radio. After the existing weather conditions as to wind currents at various altitudes, etc., have been determined by a series of short observation flights, the planes should be sent off by squadrons in sufficient number to completely cover the desired area. The plan of the search, including the exact position of the starting point, its extent, courses to be followed, etc., should be carefully made in advance, as well as a summary of the information it is desired to collect. If it is expected to encounter aerial opposition at not too great a distance, the scouting planes must be preceded or followed and supported by fighting planes.
44. The tactics of scouting planes on a search should be very much like that of the light scouting forces of the sea fleet. Depending on the character of their immediate mission and its urgency, they must be prepared to fight for their information, and if there is a good chance to pierce the enemy's aerial screen they should not hesitate to do so. If opposed by too great force they must retire upon their fighting planes in the same manner that light scouting vessels retire upon their supporting force. When sufficient power has been concentrated another attempt should be made to pierce the hostile air screen. So much for operations within the radius of action of fighting planes, which is small.
45. There is this difference between aerial and surface scouts, however. While the surface scout is usually faster than its supporting force and than the enemy vessels powerful enough to destroy it, the reverse is the case in the air. The so-called scouting plane has a large radius, but a comparatively low speed; whereas the fighting or pursuit plane has a small radius but high speed. This precludes the escape of a scouting plane discovered by enemy fighting planes out of supporting distance of its own fighting planes. Its tactics while scouting beyond the radius of its own fighting planes must therefore be quite different from that of surface scouts. It must depend upon concealment for safety. Since planes can see and obtain valuable information much farther than they can be seen, they can approach enemy positions or vessels with comparative impunity. If their presence is not suspected, only a sudden chance contact with enemy fighting planes can imperil them; since it would be impracticable for the enemy to keep a continuous patrol in the air with such short distance between units as to insure the discovery of every approaching hostile aircraft.
46. The tactics of slow long distance scouts thus reduces itself to concealment, and the pilot must be expert in taking advantage of weather conditions to remain unseen and yet be able to see himself. In clear weather, scouting at high altitudes, with great distance between planes of a scouting line, covers the greatest area in search for surface craft. In searching for submarines the altitude ought not to be over 1,000 feet and the distance between planes a few thousand yards. It is often necessary to come down if the visibility is poor, or in order to get under clouds, and sometimes it is necessary to rise over a rain squall in order to maintain vision all around it,
47. Fog of course puts an end to all search, just as it does for surface craft; and in addition may cause the plane to get lost. Fog should therefore never be entered if it can be avoided. If it cannot be kept clear of, a landing should be made before it closes in, if possible. If it is necessary to continue flying through fog, snow, or heavy rain, different altitudes previously agreed upon and differing by at least 500 feet should be taken by the planes of a scouting line to prevent collisions, Scouting at night is useless just as for ships, except to gain information of what is going on at some fixed positions where activities are in progress under bright artificial light. Under these conditions planes can come down very low without fear of being seen. The danger is of being heard, but this also is minimized if the industrial activity is such as to produce sufficient other noises to drown the noise of the plane's exhaust.
48. In approaching hostile positions or vessels, the direction of approach should be carefully chosen as regards sun, background, silhouette, etc., if the direction of the wind and other governing conditions permit. The NC-4 in approaching Lisbon on its flight across the Atlantic, is said to have been picked up at a distance of about twenty miles, being silhouetted against a western sky at sunset. High land or low cloud backgrounds, sun-glare and haze, render planes very difficult to pick up, just as they do ships.
49. So much for visibility. Audibility is almost as dangerous in disclosing the presence of aircraft and the potent factor is of course the motor exhaust. It can be somewhat deadened by approaching up the wind, but until it is found practicable to muffle the exhaust of aeroplane engines, this will continue to be a give away of an aircraft's presence.
50. For reconnaissance, as distinguished from scouting, dirigibles are best suited, on account of their ability to stop and hover over one spot while details are observed. It is evident how incomparably more accurate such a reconnaissance would be in regard to such details as size of guns, contours of defensive works, roadways, relative distances and directions, etc., especially if camouflage is employed; than a reconnaissance depending upon the fleeting glimpses from an aeroplane darting over the locality. For long distance reconnaissance beyond the radius of aeroplanes, dirigibles are the only available aircraft. Their vulnerability, however, must be constantly kept in mind. They cannot be used where aeroplanes will be encountered in force.
51. In the recent war, photography from aircraft was much used. Both plane and dirigible can be equipped for this service, but the former is probably the more efficient as it can work faster, thus enabling it to take a series of photographs of any desired area, and views of the same object from different angles, much more rapidly than dirigibles.
52. Patrol may be regarded as a form of scouting, usually in the vicinity of one's own force or bases, to insure the early discovery of the approach of enemy forces. The patrol of such areas should be systematic and regular, constituting a part of the daily routine. For this use planes should have good endurance at cruising speed, and high speed is not essential. Small dirigibles can be used advantageously.
Fire Control, Observation, and Spotting
53. The use of aircraft for fire control, observation, and spotting will next be considered. For these uses several types of aircraft are employed,—the kite, the dirigible, and the aeroplane; and there can be no question that the efficiency of fire controlled from aircraft is immeasurably superior to that controlled from a position on board the ship. Spotting from shipboard cannot be accurate at ranges of more than 18,000 to 20,000 yards; whereas from aircraft, spotting is efficient up to the maximum range of any naval gun yet developed, and the fall of shot at any range can be observed far more accurately than from the ship. Furthermore aircraft are not interfered with by the blasts of the guns, vibration, spray, the enemy's fire, and other confusing local conditions on board ship. They can spot over smoke screens, low lying mist, and beyond the horizon as seen from the ship. Except the kites, they can take position so as not to be affected by funnel smoke and gases, and sun-glare.
54. Kite balloons have the great advantage of direct telephone communication with the ship, but their many disadvantages outweigh this. They give away the exact location of the ship, which otherwise might be obscured by smoke, mist, etc. They hamper the handling of the ship, require considerable attention from those on board, and in case of being shot down might add immeasurably to the general wreckage. They have a bad whip when salvos are fired and are thus not as good spotting platforms as other aircraft. Above all their position can only be varied in height, and they cannot thus seek the best positions for observation as other types can. They are subject to much of the same interference as the ship spotters. They cannot be used in bad weather and are very vulnerable to attack by hostile aircraft.
55. Dirigibles are in many respects the best type of aircraft for fire control. They make good platforms and are roomy and commodious for the observing personnel. They can slow down and stop, thus maintaining themselves in the best position for observation, whereas planes must keep moving at high speed. But they are susceptible to bad weather and are very vulnerable to air attack, as well as furnishing a large target for the gunfire of ships. Worst of all they cannot be counted upon as always available, since they cannot accompany a fleet at sea indefinitely, but can only operate within their radius of action from some fixed base on shore. Thus the dirigibles may not be present when most needed, if it happens that the theater of operations does not contain a dirigible base within radius of action of where the opposing fleets make contact.
56. Planes are therefore probably the most reliable and dependable type of aircraft for spotting purposes. They can go up in almost any kind of weather, are better spotting platforms than kites, and have all the advantages conferred upon them by mobility in selection of position for observation, etc. They can, before the action begins, report the movements of the enemy over the horizon or behind smoke screens, thus permitting fire to be opened at the earliest practicable moment. This is important with the modern long range gun. which can fire much further than its shots can be accurately spotted from the ship. The great disadvantage of planes which is not shared by kites and dirigibles, is that they must keep going at high speed throughout the entire time they are spotting, which in a prolonged action when reliefs cannot be furnished, subjects the personnel to great strain.
57. Kite balloons are so restricted as to action that there is not much room for a choice of tactics. They stay on the job as long as possible and can vary their altitude somewhat to secure the best conditions for observers. But other than that they are helpless and defenseless. Dirigibles should keep in the vicinity but well above the firing ship. They must of course keep entirely clear of the trajectory of the projectiles, as must also planes, and cannot therefore go very far between the firing ship and the target. To fly over the target would be too hazardous in view of their vulnerability. If attacked they must take such steps to beat off the attack or make their escape as they would under any other circumstances, without, unless unavoidable, leaving their station until some other means of spotting can be resorted to, and for as short a time as possible. Defense should generally be left to friendly fighting planes.
58. The tactics of planes in spotting, which have so much greater freedom of action than the other types of aircraft, are more capable of elaboration. Their first care must be to keep in such position that the observer can see the target uninterruptedly, unobstructed by the interposition of wings, tail, etc. The altitude should in general be from 1,000 to 5,000 feet so as to obtain the best visibility conditions. They must keep out of the trajectory of the projectiles. As the maximum ordinate of the 14"/50 caliber gun is nearly 5,000 feet, at 20,000 yards range, and over 7,000 feet at 25,000 yards, the danger can be seen of getting midway between firing ship and target. To take position over the target would expose the plane to destruction by hostile action, and possibly prevent its getting back in case of need, through the trajectory of the guns of its own side. It is best therefore to remain in the vicinity of the firing ship, and maneuver to pass over it, flying towards the target at the instant the first salvo is fired. The plane should then turn at right angles and fly back and forth in front of the firing ship in a sort of figure 8, always turning toward the target so the observer will not lose sight of it. As each salvo is fired the pilot must turn the nose of the machine slightly toward the target so as to prevent the observer's vision from being obscured by a wing.
59. Primary communication except in the case of kites is by radio telephone. The plane should be warned before the first salvo and thereafter the word "fire" sent out at the instant of firing. Visual signals constitute the secondary system of communication. Flags or streamers are used, different colored smoke puffs, or prearranged maneuvers of the plane itself. The secondary systems are slow and not very flexible, but the radio telephone is quick and accurate and the corrections from a plane should be in as soon as the ship spotter's.
60. There is a type of aircraft thus far little developed which has the promise of being an ideal machine for fire control and observation. This is the helicopter. With propellers of sufficient lifting power and for motion in horizontal translation, the helicopter could make headway or hold its own against the wind, and thus remain stationary in midair or move to any desired point. Such a type would have all of the combined advantages of the plane, the dirigible, and the kite, with practically none of their disadvantages. In addition to its ability to hover, its chief advantages are the ease with which it can be handled from the deck of a ship, especially as compared to the cumbersome kite or dirigible; the absence of the inflammable gas essential to these two types; and its invisibility and invulnerability as compared to them.
Protection of the Fleet
61. The fourth use for aircraft to be considered is the protection of the fleet. Protection may be considered under two heads: warning of the approach of hostile craft of the air, sea or sub-sea; and the destruction or driving off of such craft. The types of aircraft needed for warning will be different from those needed to destroy or drive off the enemy. And also, the types needed to combat hostile aircraft will be different from those needed to combat surface craft or submarines. In fact, for the task of protecting the fleet practically all types of aircraft will be needed. The various duties of the protective force and the types needed for each will now be considered.
62. For protective scouting, planes can be used to a limited extent, but dirigibles are more efficient on account of their ability to remain in the air for much longer periods, and to stop and regulate their speed more easily to that of the fleet. The difficulty of maintaining large rigid dirigibles with the fleet far from their shore bases would practically preclude them from this duty. Small non-rigid types such as the Baby Blimp would be good craft for this work, provided the problem could be solved of caring for them. This use of dirigibles as protective scouts is merely suggested as a possibility of the future. If their value in this capacity is thought to be sufficient, the problems involved might be found possible of solution. Or a new type, intermediate between the plane and the non-rigid, might be developed possessing some of the ease of handling of the former with the endurance and stability in the air of the latter.
63. In any case it cannot be seen that dirigibles possess any great advantages over surface craft for protective scouting, except speed and greater radius of vision due to their higher altitude. They would be efficient for picking up enemy surface craft; but since they can be seen by submarines much further than they can see them, no submarine would have any difficulty in keeping out of their sight by submerging. While it is true that they can see below the surface under certain conditions, deeper than surface craft, this distance is very limited even under the best conditions on the high seas, and submarines can always avoid detection by submerging deeply enough. Against aeroplanes they would be helpless since the latter are greatly their superiors in speed and invulnerability. From such distance as they could see hostile aeroplanes they could be overtaken and destroyed before they could either get back to the protection of their own forces or be supported by their own fighting planes, unless these were present with them; in which case they could as well do the scouting themselves and there would be no need of the dirigibles at all.
64. For gaining information of the presence of submarines, hearing must be depended upon rather than sight. The listening devices of surface craft are the best although not a certain means of detecting submarines. In this respect ships are superior to aircraft for protective scouting against submarines; and since dirigibles are helpless against enemy aeroplanes, the only advantage they possess over ships for protective scouting in general is the greater distance they can see enemy surface craft. This advantage is hardly sufficient to warrant the risk of loss attending their use, and hardly worth the trouble of overcoming all the difficulties and problems connected with maintaining them with the fleet.
65. For protective scouting by air forces we must therefore depend upon the plane, and since these cannot keep the air indefinitely, the best that can be done is to send them out periodically, say at dawn and at dusk. They can thus cover the day and night circles of the fleet, and can at least insure that no surface craft are within striking distance. The discovery of submarines would be pure luck, and aircraft can run in so rapidly that they cannot guarantee the fleet against their undetected approach. So much for the first duty of aircraft in the protection of the fleet.
66. Now as to their ability to drive off or destroy attacking hostile craft. Against surface and sub-surface craft, bombing planes would be the chief reliance. Against surface craft only, there may be added torpedo planes and fighting planes heavily armed with guns. The employment and tactics of these will be discussed under the next subject. Suffice it to say here that for the adequate protection of the fleet, there must be kept ready for instant flight as many as possible of all these types of planes.
67. Before leaving the subject a word will be said regarding smoke screens in connection with protective scouting, and the possibilities of aircraft in relation to them. It has already been mentioned that aircraft can spot over smoke screens which would be impenetrable to observers on surface craft. So also in observing in connection with protective scouting, aircraft can develop what lies beyond smoke screens laid by the enemy to hide their movements in proximity to the fleet. Information as to the types and number of ships, formations, courses and speeds, and changes of these, can be sent with speed and accuracy to a commander-in-chief blinded by smoke or separated from the hostile forces by an impenetrable pall. Radio telephones would of course be used to transmit this information, as long as they were available. 68. Aircraft dropping smoke bombs can with efficiency and despatch lay smoke screens as designated by the commander-in-chief much more easily and quickly than the same can be done by the comparatively slow movements of surface craft—even destroyers. The fleet could be thus hidden from the approach of hostile craft; or after discovery can be shut out of view while changes in dispositions are made. Hostile air attacks can conceivably be broken up in this manner, by exploding smoke bombs at altitudes which possibly could not be reached by the smoke screens of surface craft.
Attack on Enemy Surface and Sub-Surface Craft
69. The fifth use which will be considered is attack on enemy surface and sub-surface craft by air forces. For this, three different weapons are available: the bomb, the torpedo, and the gun. Each of these is best carried by a special type of aeroplane, but they are to a certain extent interchangeable. It has been demonstrated by the recent American experiments off the Virginia Capes that any ship at present in existence can be sunk if enough bombs of adequate size can be placed upon or around her as desired. Bombs up to 2,000 pounds were used and there are at present in existence, bombs of double that weight. The greatest effect from bombs seems to be obtained not by direct hits but by dropping them close alongside the target, where the action is the same as that of a submarine mine.
70. The advocates of the aeroplane are enthusiastic in their predictions of what they will be able to accomplish in future wars, while the adherents of the battleship are by no means hopeless of being able to meet the peril. So much on both sides has been written and made public, including the official report of the Joint Army and Navy Board, upon the experiments, that it is not purposed to discuss here the pros and cons. It is sufficient to know that a new and very promising method of conducting hostilities on the seas has made its appearance, and constitutes a grave menace to the safety of surface fleets. An attempt will be made to indicate briefly the lines which the development of this new mode of attack will take and the means which should be taken to meet it.
71. When a hostile fleet is discovered and its position reported within flying distance of air stations either ashore or afloat, the forces must in the future be considered to be not only in tactical contact, but within range of each other's projectiles. Heretofore it has been of vital importance to open fire at the maximum range at which it is thought that hits can be made with the guns, and the difference of a few minutes has been sufficient to give the side which lands the first salvos a tremendous if not a decided Initial advantage. So much was this appreciated that in the naval actions between the British and Germans in the recent war, fire was opened practically simultaneously. Applying the same principles to the use of aircraft it will be of vital importance to land the first bombs upon the enemy's fleet. This will put the same premium upon increasing the flying radius of bombing planes as was put upon increasing the range of guns, and every effort will be made to get in the first air attack.
72. It is hardly to be supposed that a fleet will approach a hostile coast protected by aircraft, without having command of the air. We shall therefore eliminate this case and confine our attention to that of two fleets approaching striking distance of each other, outside of flying distance from any shore stations. Each will probably strive to deliver the first air attack, just as formerly each tried to land the first gun salvo. But there is a difference in the two cases. The ability to land the first gun salvo defends only upon the range of the guns, and the skill of the personnel in handling them. The ability to land the first bomb depends upon the ability to force home the attack against hostile resistance, much as destroyer or submarine attacks would be made prior to a major action. Means must be provided therefore to break down any resistance encountered. Since the effect of anti-aircraft batteries is practically negligible, the resistance to be reckoned with will be in the air. To overcome this, fighting planes must be sent out in advance to secure temporary and local command of the air. In view of the importance of making the bomb attack as early as possible, the bombing planes will follow close upon the fighting planes, or even accompany them and slip through the hostile fighters while the attention of these is fully engaged.
73. If the opposing air forces are strong and evenly matched, neither side can hope to secure undisputed command of the air for some time, and advantage must be taken of every opportunity to break through. Air attacks must follow each other as frequently and in as great force as the number of planes available and the results of previous engagements in the air permit. The bombing planes must be sent out in squadrons as large as possible, to secure what corresponds in gunnery to volume fire; protected by all available fighting planes. To pursue the analogy, rapidity of fire with guns would have its counterpart in the rapidity with which the squadrons could follow each other out. The destruction of planes before they reached the target would in the same way correspond to the silencing of guns on board ship.
74. The details of the attack and the manner of delivering it must be left to the flight commanders and the individual pilots in the same manner that it is left to flotilla and commanding officers of destroyers. The manner of approaching the target and of releasing the bombs, with allowance for wind, speed, drift, bomb trajectory due to its coefficient of form and specific gravity, etc., is a matter of training and instruction, rather than of tactics, and will not be discussed here.
75. Thus far no assumption has been made as to daylight or darkness, but the foregoing remarks apply chiefly to daylight conditions. Provided the target can be found, darkness offers much greater chances of success to bombing aircraft than daylight. But even if the position of the enemy's fleet was accurately known at dusk, which is all that can reasonably be expected, drastic changes of course and speed in addition to the fact of its being darkened, will make its discovery from aircraft a very difficult matter. Add to this the well-known difficulties of aerial navigation on trips of any distance, enhanced by darkness, as well as the difficulty of keeping other planes of the attacking formation in sight, and some idea can be formed of the obstacles which will be encountered by the attacking planes.
76. If the movements of the enemy fleet have been closely followed after dark by scouting planes or other means, and its position can be predicted within narrow enough limits at the moment the air attack is to develop, much of the bombing plane's difficulty disappears. With good weather conditions—that is a clear night, preferably moonlight with a wind whose force and direction can be counted on to hold—planes should be able to locate a hostile fleet sufficiently closely to disclose it by means of parachute flares.
77. Prior to the armistice, flares of 2,000 candle-power supported by eighteen-foot parachutes were constructed which burned up to eleven minutes. Since then flares have been developed of 200,000 candle-power capable of illuminating an area five miles in diameter and of making it as clear as day. The construction of flares of 1,000,000 candle-power is planned. The parachute screens all space above it and reflects the light downward so that the planes can operate unseen in the gloom above while everything on the surface of the sea is clearly disclosed.
78. A night attack upon a fleet would be conducted by sending out in advance a number of planes to drop parachute bombs over and around the hostile ships. These would be closely followed by the bombing planes, which, having picked their targets by the light of the flares, could attack them either before or immediately after the flares became extinguished. It is thought that the bombing planes would be in no very great danger even if they attacked in the light of the flares. Since the whole attack would be in the nature of a surprise, the anti-aircraft batteries would be of little use and the protecting planes would not have time to take the air. If they attacked after the flares had expired, they could fly down in the darkness as low as they desired so as to be certain that each bomb reached its mark.
79. The defense against such an attack would at best be haphazard on account of the difficulty of finding planes in the vast space of darkness, by the uncertain aid of searchlights or star shells fired at random. The best, if not the only defense against such an attack would be the putting out of action of the enemy's plane carriers from which the attack would emanate, before darkness set in.
Types of Bombs
80. Various types and sizes of bombs are available for use from aircraft. First, demolition bombs weighing from 25 to 4,000 pounds, loaded with high explosive comprising more than fifty per cent of their total weight. These are primarily for the destruction of material, but incidentally destroy personnel as well. Second, numerous kinds of asphyxiating, poisonous, and tear gas bombs, designed for exerting different effects. These are for use solely against the personnel, some of which kill outright, while others produce temporary blindness, asphyxiation, etc. It is expected that the fumes of these bombs will enter the ventilating ducts of the ship and permanently or temporarily disable all the personnel in artificially ventilated compartments, as well as those on open decks within considerable radius of the explosion. These bombs may thus do more to put a ship out of action than the direct but more or less localized destruction caused by demolition bombs.
81. Finally, there are smoke bombs designed either to shroud the ship in a pall from which nothing can be seen, or as a smoke screen through which air and surface torpedo craft can attack. The effect of all these bombs has been so well demonstrated in the recent American experiments upon the ex-German warships and the Alabama, so completely reported upon, and so thoroughly discussed, that nothing further can be added here; and those interested are referred to the official reports upon the tests.
Torpedoes in Aeroplanes
82. We shall pass on then to the consideration of the next weapon available to the aircraft—the automobile torpedo. At first sight this appears to be a formidable weapon, but both the weapon itself and its mode of handling from aircraft present certain difficulties. First as to the weapon itself. To begin with, a large proportion of the weight of a torpedo is taken up by the air flask, machinery, tail, etc. This is of no destructive effect. Hence the useful load as regards destructive power of the torpedo is small compared to the useful load of the bomb. The weight of the explosive is only about twenty per cent of the total weight of the torpedo; whereas in the case of the bomb the weight of the explosive is fifty per cent or more of its total weight. Comparing a bomb and a torpedo of the same weight, the former has two and one half times as much explosive as the latter. This is of course partly made up for by the fact that in the case of the torpedo the explosion, if it occurs at all, is in direct contact with the hull of the ship; whereas with the bomb, it is at a distance corresponding to the skill with which it is dropped.
83. The mine effect is thought to be the greatest which can be produced by a bomb. A direct hit of a bomb may do terrific local damage, but would probably not endanger the stability of the ship to as great an extent as a hit of a torpedo carrying the same weight of explosive. To secure the same effect a bomb must be dropped exactly alongside. But two and one half times as much explosive can be carried in the form of bombs as torpedoes. If this is carried in two bombs, there are double the chances of placing one so as to do as much damage as the torpedo. At present no attempt can be made at figuring out the relative chances of making hits with bombs or torpedoes.
84. In the next place the structural defense against underwater explosion is being vastly improved as a result of the recent war, and the future dreadnaught may be less vulnerable to under-water attack than attack from the air. It is however to be expected that steps will be taken to protect ships against attacks from the air as well, and it is impossible to say which will be the more effective until it is known what protection will be embodied in the future ships against each. At present it would seem that both weapons have possibilities warranting development, and skill in the use of each should be striven for.
85. Now as to the mode of handling torpedoes from aircraft. The latter must come down to within twenty feet of the water in order to successfully launch a torpedo. Too great a height or speed of plane will result in damage to or derangement of the torpedo which will prevent its running. Now, when a plane comes down to fire a torpedo in this manner, it deprives itself for the time being of one of its greatest assets—the ability to maneuver in the third dimension. It reduces itself temporarily to practically the limitations of a surface craft, except as to speed. It becomes exposed to the same danger of being picked up, and to the rapid fire of secondary batteries, in the same manner as surface torpedo craft; but the plane is much more vulnerable, not only to direct hits by the fragmentation of shrapnel, but to splashes, which would wreck it by tearing its wings, rudders, and stabilizers to pieces. An effective splash barrage laid just ahead of attacking torpedo planes would probably prevent their passage, even if light metal were substituted for fabric in their construction.
86. Another disadvantage of the torpedo is its relatively slow speed. The plane can reach the target quicker than the torpedo which it launches. One naturally asks then, why not have the plane continue its flight and attack the ship with bombs from a relatively safe altitude, instead of using torpedoes at all, from a dangerously low level? The possibility suggests itself of the development of an aerial torpedo which would be more accurate than the bomb, and have none of the limitations of the water torpedo.
87. However, let us consider the tactics of the torpedo plane and its weapon as they at present exist. Having reduced itself, except in the matter of speed, to the Status of the surface torpedo craft, it must attack in much the same way as the latter. Its greatest chance of success would be at night, or through smoke screens. The attack should be delivered in divisions or squadrons of planes from the most advantageous angles for making hits, provided the force and direction of the wind are not governing factors in the handling of the planes themselves and the laying of the smoke screens. The screen can probably be best laid by a squadron of aeroplanes carrying smoke bombs, and co-operation between these and the torpedo planes must be worked out in advance to prevent collisions, interference, etc., as well as the method of retirement of both types. The manner of delivering the attack must be left to the flight commanders and pilots just as in the bomb attack. Incidentally it may be remarked that much difficulty must be expected in estimating from aircraft at night the course, speed, and range of the target vessel.
Guns on Aircraft
88. The third weapon available for attack on ships is the gun. During the Great War only machine guns were used, each fighting plane carrying two: one mounted on the upper wing, and one in front of the pilot. The Lewis gun was the type used practically exclusively by the Allies on the upper wings; and, after synchronizing gear was invented for firing through the propeller, the Vickers was standardized for this kind of fire and used to the exclusion of all others. The latest practice is to use both of these types of guns in pairs, in twin mounts, in order to double the volume of fire.
89. More recently one and three pounder automatic cannon have been mounted, and a three-inch semi-automatic for use on aircraft is being constructed. These guns will greatly increase the offensive power of aircraft against the fire control tops, bridges, upper works, and exposed personnel of ships. They will be particularly effective against destroyers, whose personnel is absolutely exposed, whose light decks and side plating could be completely riddled, and whose anti-aircraft defense is necessarily feeble.
90. For use solely against personnel—landing forces in open boats or on beaches, troops in trenches or on the march, and columns of troops and transport on congested roads—the latest development is the Larsen all-metal plane. It has a speed of 140 miles an hour and carries thirty machine guns of 45-cal.
These are mounted along the bottom of the fuselage so as to fire directly down. Each gun fires at the rate of 1,500 shots per minute, or 45,000 shots per minute, total rate. The effect of such a blast upon the open decks of lightly protected vessels can be imagined; but their principal use is against troops, and they would be very valuable in repelling a hostile landing.
Escort
91. The fifth use of aircraft is for the escort of surface ships. This includes both the escort of fighting ships and of convoys, and is primarily for defense against submarines, although it would also be effective against hostile aircraft. In the future, every battle fleet and scouting detachment will, where conditions require it, doubtless have its screening force of aircraft similar to its screening force of destroyers. But the air escort will be particularly valuable for convoys through submarine waters; and it was for this purpose that it was used with great success in the recent war, along the coast of England, in the Channel, and on the coast of France.
92. When escorted by aircraft there were almost no cases of attack on convoys by submarines, and hardly a sinking while the aircraft were in the air ready for duty. German submarines always submerged when a plane was discovered. The tactics of aircraft were to bomb the submarine if possible, but in any case to drive it under at such a distance from the convoy that with its low submerged speed it could not get into position to attack. If the submarine was driven under ahead of the formation, the aircraft could by signal divert the convoy and guide it clear of the danger. It could also lead escorting surface vessels to the attack when it could not itself damage the submarine, occupying as it does the most advantageous position for spotting submarines awash or just submerged, and for noting oil slicks, wakes, etc.
93. Dirigibles are especially suitable for convoy work if there is no danger of contact with the hostile aeroplanes, as they can regulate their speed more easily to that of the convoy by stopping, hovering, etc., there is less strain on the personnel, and they can accompany the convoy much further than planes. But for the actual attack on submarines, planes are superior on account of their rapid maneuvering qualities. Escorting aircraft must always keep their mission in mind—the protection of the convoy. On no account must they leave their station and be lured away in chase of some real or imaginary enemy at such a distance that he could not possibly harm the convoy. The position of the suspected enemy can be reported and other craft sent to deal with him, but not the units of the escort. There is too much chance of another submarine, perhaps co-operating with the distant decoy, coming in during the absence of the escort and playing havoc with the convoy.
94. Escort is closely allied with mine and submarine search in general, both of which can be ably performed by aircraft if the water is sufficiently clear and the character of the bottom is favorable. The high position of the observer from aircraft gives him a great advantage over one on a surface ship, in penetrating beneath the surface of the sea. Some success was had in locating mine fields and submerged submarines in the Great War, even under the disadvantageous conditions of the North Sea.
Dispatch Carrying
95. The remaining uses of aircraft as listed at the beginning of this paper, are of a minor character. In the present day of rapid and accurate communication, dispatch carrying does not have the importance which it did before the employment of radio. However, there can conceivably arise cases when the rapid transmittal of secret maps and plans which from their nature cannot be sent by radio or telegraph may be of the utmost importance. In such cases the aircraft offers the most convenient mode of transportation. The type of craft used for this purpose is of no importance except as limited by the urgency of the matter, the distance involved, and the conditions to be met en route. The selection of the best type from those available will of course be made. Since the capabilities of different types have been touched upon in considering the uses of aircraft already discussed, there is no necessity for trying to determine here the best machine to use in every possible contingency.
Transportation
96. The above remarks apply in great part to the transportation of personnel and of small vitally needed articles of material. It may be necessary to get a commanding general rapidly to the front, or to an urgent conference at a specific time; or to transfer a naval commander-in-chief from one ship of his command to another at considerable distance. It may be necessary to send vitally needed chemicals or important spare parts to ships or organizations at the front. The aircraft again furnishes the most serviceable means.
Evacuation of the Wounded
97. The employment of aircraft to transport the seriously wounded has already been tried and planes have been fitted to carry them. But the capacity of planes for this purpose is necessarily so limited that this means of transporting the wounded cannot be expected to cope in any way with the conditions of modern battle. Furthermore it could only be used from localities suitable for landing and not under fire. It could be used to transfer a few men from isolated positions where ordinary means are not available, to base hospitals; provided a sufficient number of planes can land there with reasonable assurance of success. This use is more applicable to times of peace or inactivity, for the transport of individuals from outlying districts to base hospitals for urgent operations, than it is to the conditions of battle. Dirigibles could possibly be fitted as hospital ships, but it is doubtful if the results would warrant the outlay. Military exigencies would not at present countenance the diversion to that use of such important aerial units. When dirigibles become as numerous as ships, we may possibly see such hospital ships of the air.
Control of Operations from the Air
98. As to the control of operations from the air, it is not believed that this has been tried upon any large scale. It is mentioned as a possible suggestion for the future. A birds-eye view of a situation, particularly during an approach or an attack on shore, might be of more value to a naval or military commander-in-chief than all the mass of conflicting information sent in by other means. Of course the risks involved in a commander-in-chief leaving his flagship or headquarters must be fully weighed and he must be in direct and instant communication therewith at every moment of his absence. His flight should in general not carry him too far or absent him too long. Control of operations from the air should be primarily valuable in making dispositions prior to the opening of fire, and it would seem that it should terminate before that event; as otherwise there is too much risk of the commander-in-chief being lost or permanently separated from his command. This applies more to conditions at sea than on shore.
99. It might be perfectly practicable for superior officers of land forces, other than the commander-in-chief, such as army or corps commanders, to control operations along their sector of the front from a properly safeguarded dirigible operating some distance behind the lines. Their ability to visit any part of the sector and observe details of troop movements and concentrations far back into the enemy's zone, with their consequent ability to order instant countermoves or to take advantage of obvious weakness, which if reported to headquarters in the usual manner would be so delayed as to lose the opportunity for decisive strokes, should go far to outweigh any attendant risks.
100. At sea conditions are very different. There is no fixed battle front as on land. Kaleidoscopic changes in tactical situations and groupings of forces occur. Hostile forces can make their appearance from any direction. Moreover, sudden changes in weather conditions may reduce or destroy visibility. The flagship does not remain in one place as does headquarters ashore. It would therefore appear extremely unwise, in the present stage of development of aircraft, for a naval commander-in-chief to thus separate himself from his fighting forces during an engagement.
101. In the future, development may so increase the stability, defensibility, and importance of aircraft, that the commander-in-chief can embark with as much safety in a powerful unit of the air force as in one of the sea fleet. In fact air forces may become so increasingly important in future wars as to overshadow the importance of the surface fleet. It is conceivable that the major action of the future may possibly be fought in the air, with the surface craft as the auxiliary force. The director of operations should be with the main force—that is in such case in the air. It will be, from the present outlook, a far cry to such a situation; but this should not prevent due consideration of the advantages of directing operations from a swift and reliable unit of the air force.