CHAPTER XIV.
(December 4th, 1914)
AN INDEPENDENT AIR FLEET AND ITS DUTIES. AIR TACTICS AND FORMATION FLYING. AIR AND NAVAL TACTICS: CONDITIONS COMPARED.
§ 91. Need for an Independent Combatant Air Fleet. The subject of aeroplane tactics, or air tactics, may be said to lie wholly with the future. Hitherto the aeroplane has acted in its combative capacity as an individual unit; there has been no systematic co-operation between a number of machines for the organised destruction of the enemy aircraft, such as could be described as tactics in the military sense.
Before we can usefully discuss the present branch of the subject we must look forward to the time when air fleets or squadrons will be organised for the purpose of operating together according to some well-understood, or prearranged, scheme as combatant units. We have already defined the duties of attack and defence by air against the air forces of the enemy as constituting the secondary function of the Aeronautical Arm. This being the mainspring from which the tactics of the air must derive its motive, we require to take for our foundation the material provided by our previous consideration of the primary function of the Arm.
The initial condition of the problem, then, is that both combatant armies are provided with reconnaissance machines of two types, namely, the long-distance or strategic scout—an unarmed machine built for speed and endurance, and the tactical scout, probably mounting a machine-gun, and protected by light armour from attack from below. Possibly also there will be a type more especially designed for lending support to ordinary military operations, on the lines already foreshadowed, protected beneath by heavier armour or by point-blank-proof shields, and mounting a multiple machine-gun, or a mitrailleuse having three or four barrels, and capable of firing 2,000 to 3,000 rounds per minute. Further than this, there will without doubt be machines expressly constructed for bomb-dropping, in addition to specialised naval types; these, however, do not require particular consideration, since, in view of the weight they have otherwise to carry, their power of offence against hostile aircraft (as measured by their gun-power) will of necessity be feeble.
In the absence of any organised air fleet intended for the destruction of the types as above defined, there will take place, indeed as is already the case, a certain amount of desultory fighting of a local character; at one point the aircraft of one belligerent will secure the advantage, and at some other point the reverse may be the case. So long as neither air force possesses any marked superiority in the matter of speed, and so long as neither army has at its disposal more machines than are reasonably necessary for the reconnaissance and other services mentioned, we cannot anticipate that the results of such aerial combat will be decisive in any sense. We may assume that numbers may combine in order to overweight the enemy locally, and drive him out of action; the advantage obtained, however, will only be temporary. In such desultory air warfare there will be a continual wastage of men and machines, but these losses can be made good by new units and new formations.
In order to effect anything decisive, an organisation of an entirely new character is required: an air fleet absolutely free from any routine or other set duties, whose one and only object is to seek out the enemy's aircraft wherever reported, and effect their destruction with the utmost swiftness and despatch; in brief, an independent air fleet, whose unchallenged existence alone stands for the command of the air.
§ 92. The Independent Air Fleet. Air Tactics. It may be laid down that the independent air fleet, in order that it shall be capable of fulfilling the duties assigned to it, must be strong by virtue of numbers. In order to destroy—i.e., not merely to drive away—the active aircraft of the enemy, it must be of decisively higher speed, so that the enemy, whether reconnaissance or fighting machines, will be compelled to surrender or give battle. An exception may be made in the case of the strategic scout, which, being designed purely for speed and being burdened with neither armour or armament, may be taken as, within reason, faster than anything that can be brought against it. This need for superiority in the matter of speed means evidently that the air-fleet type must suffer in some degree in the matter of armament; alternatively it must be a heavier type machine for machine. Closely allied to the question of speed is that of climbing power. Other things being equal, whether for increased speed or for increased climbing power, a greater horse-power per unit weight is necessary. If we assume some given value for the horse-power per unit weight, then a machine may be designed either to develop the highest flight speed possible or to obtain the greatest rate of altitude increase—i.e., vertical velocity. Any actual design is of the nature of a compromise; maximum flight speed is kept as high as possible consistently with obtaining a sufficient rapidity of ascent. The independent air fleet must be, without question, the master of the service machines whose destruction it is required to encompass, both in the matter of speed and climbing capacity. Thus it will require to possess a considerable superiority in the essential matter of horse-power; it must be made impossible for its prey to escape either by horizontal flight or by putting on altitude.[1]
§ 93. Tactical Importance of Altitude. This question of altitude is one of really vital consequence in connection with the tactics of the air. The service machine designed to fulfill the primary function of the Arm must evidently carry its protective plating or armour distributed in such manner as best to resist gun-fire from below. Also the armament is necessarily directed mainly to the downward projection of missiles, by gun-fire or otherwise. Hence to obtain the "upper berth" in an air-fleet action is at the outset to secure a great tactical advantage. It might be supposed that these considerations will lead to an increase in the protection accorded—that is to say, that the service fighting-machine will be fitted with a complete panoply of steel plate, above as well as below. This, however, is improbable, since any such measure would, by reason of the additional weight, so reduce the general mobility of the machine as to constitute too serious a handicap. It would appear to be only possible to ameliorate the conditions under which a machine will have to fight when resisting an attack from above by arranging the gun armament with as great a capacity for upward fire as possible. A further advantage in the possession of the upper berth or "gage" lies in the fact that the potential energy, represented by the difference of altitude, may, at any time, be used to augment the velocity of flight above normal, a power which cannot fail to be of real tactical value.
§ 94. Air Fleet must he Homogeneous. It is a fact which cannot be too strongly stated that the independent air fleet must be homogeneous. It must be composed of units of approximately the same capacity of speed and climbing power; the range of its weapons also should be the same. As a counsel of perfection, the fleet should be of one design, mounting one standard type of gun, using one kind of ammunition. Owing to the need for aeronautical ascendancy, we have seen that the armament cannot be of the heaviest; it may more often than not be individually less powerful than that of its opponent. The independent air fleet must therefore base its strength on its numerical superiority. It is precisely here that the need for homogeneity becomes manifest. Properly to assert the power of numbers, the whole fleet must come into action as nearly as possible as a single unit; in brief, it must concentrate the whole power of its combined fire on the numerically inferior enemy, and so take full advantage of the n-square law. No fleet can accomplish this unless its components are able to move and act in concert; thus the slowest vessel in a fleet must regulate its speed, and that which has the weakest armament the battle range.[2] In the case of the air fleet also we have the slowest climber determining the rate of ascent.
§ 95. Air Tactics. Formation Flying. In order that the air fleet shall be brought into action as a single unit, it is not only necessary that it should be in its constitution homogeneous, as already pointed out, but it must also be handled in some definite formation. Where the numbers are moderate, as, for example, in the handling of a single squadron, the formation adopted may evidently be fairly elastic, and there will be no difficulty in bringing the tail of the formation promptly into action. When, however, as we may suppose will some day be the case, the numbers become great the whole question cannot fail to become one of the first magnitude. The actual importance will again be greatly increased when air fleet meets air fleet, for in view of this eventuality, numbers will be augmented to an extent that we have as yet no means of gauging, perhaps beyond anything that we can at present imagine.
It would not serve any useful purpose in the present state of knowledge and development to attempt to discuss too closely the types of formation that may or may not be found suitable. We have the same, or an analogous, tactical problem in each of the older arms of the military organisation, and in the Navy, and in every case, in spite of the store of practical experience available, there is still a deal of controversy, different ideas being represented by different "schools" of thought; even in the case of the oldest Arm of the Service — the infantry, there is no unanimity of opinion. This being so, it would clearly be futile to attempt to lay down any scheme for an arm which cannot yet be said to exist. However, in spite of all this, there are certain outstanding facts that cannot fail to have some bearing, and will assuredly act as controlling influences.
§ 96. Formation Flying. Airmanship and Signalling. When the numbers become great a point will inevitably be reached when the accuracy and closeness of the formation will be a matter of first importance to the tactical scheme, since the only way in which the whole force can be brought to bear at once will be by a studied plan, in which each machine will have its allotted place. In other words, the number of machines from the point of view of the n-square law will no longer be the number brought into the field by the strategic plan, but rather such portion of it as can be brought to bear simultaneously on the enemy; it will become a battle of airmanship. One of the difficulties which exists to-day, and probably will always be a matter of anxiety, is that of signalling; and to whatever extent this remains a difficulty, the flexibility of the formation will be impaired. The air fleet with the most perfect system of signalling will be the best able to take advantage of any opportunity that may arise in the course of an engagement by adapting its tactical scheme to the needs of the moment. In order to render it possible to control large numbers, it would appear to be evident that the unit command will be a small group, or what is at present termed a "flight" (some four or five strong), and that the individual machines will act on the plan of follow-my-leader; in other words, they will have instructions to keep station. It may be found desirable to extend the same system to larger units, as tending to avoid possible confusion.
§ 97. The "V" formation and its value. There is a point in connection with the pattern or character of these unit formations which may turn out to be of importance. It has for long been observed that certain birds, flying numbers strong (as in migration), are in the habit of assuming definite formation, and that this formation is of the shape of a letter V travelling point first; each bird, besides being some distance behind its leader, is also somewhat on one or the other flank. The reason for this is almost certainly one of aerodynamics; the air immediately in the wake of a bird in flight has residuary downward motion, and so is "bad" air from the point of view of the bird following. On the other hand, the air to the right and left of the leader has residuary upward motion owing to the vortical character of the wake disturbance, and so is "good" air; consequently the V formation arises naturally from each bird seeking the air which gives the best support, a matter in which most birds show consummate skill. There is very little doubt but that, by this manner of flight (formation flying in fact) a flight of birds is able to cover the ground with a material saving of work done. If the point in question is as important as it appears, it will certainly have to be taken into consideration in connection with aeroplane tactics, and more particularly formation flying. The follow-my-leader formation will evidently be on a V or diagonal plan rather than in line ahead.
§ 98. Formation Flying. Machines disabled. Whatever formation plan be adopted, it is evident that provision must be made for machines shot down or disabled to be able to leave the lines without creating confusion; evidently the closer the formation the more danger there will be of a real mix up and debacle in case of any confusion arising. Similarly, it is important that the enemy shall not be able, by ramming tactics or otherwise, to throw the formation out of gear; once more the "upper berth" clearly has every advantage.
§ 99. Conditions in Aerial and Naval Tactics Contrasted. The conditions, both as to armament and otherwise, which obtain in the Navy and in the Air Fleet offer many striking contrasts, the disparity is such as should preclude too much reliance being placed on analogies between the Services, except where the issue under consideration is of the broadest description. The range of the gun-fire of an aeroplane (or other aircraft) is less a matter of the ultimate range of the gun employed than it is of the angular magnitude of the objective and of those other factors, such as speed and light, which contribute to render accurate shooting more or less difficult. In this the conditions differ remarkably from those which obtain in the Navy, where the useful range is, roughly speaking, the ultimate effective range of the weapon employed. Thus in air warfare the craft carrying the heavier guns will in nowise possess the advantage that accrues in the corresponding case in the Navy. To a certain degree the larger aeroplane (or airship) will be penalised by the fact that it offers a target of greater area, and hence it will be more vulnerable. It may therefore be anticipated that the trend of design in the fighting machine will not be in the direction of very heavy units analogous to the battleship, but rather in the construction of machines of moderate size and weight, with the maximum possible rate of fire. As pointed out in one of the earlier articles, this rate of fire will be measured by the number of projectiles per second, rather than by their weight or striking energy. Whilst pointing out that the large aeroplane does not possess the marked advantage over the smaller, which, in the Navy, has led to the development of the Dreadnought and the super-Dreadnought, the author does not wish it to be inferred that his opinion is against the reasonable development and growth in the weight and dimensions of the fighting-machine. It may, indeed, be found when the size of air fleet becomes great, that, owing to the numbers becoming unwieldy, the only way in which the fighting strength can be increased will be by increasing the power of the individual unit—i.e., by employing larger machines, mounting more guns.
Again, the larger machine, owing to its less relative body resistance and other well-understood causes, has a lower coefficient of traction, and so, where the speed is important (as we may always assume to be more or less the case), the advantage is with the larger machine. Alternatively, the larger machine, speed for speed, will, with equally good design, be the better climber; these points have already been discussed to some extent; it is only necessary here to draw attention to their influence. It would thus appear that there is nothing to be gained at the present time by attempting anything heroic in the direction of aeroplane design; the large machine will come (if it does come) by a natural process of evolution.
In contrast to the large machine the present author has frequently expressed the opinion that the single-man machine for many purposes would be able to effect all that is required of it (chiefly reconnaissance), and in this he has found himself opposed by the official specifications of the Departments concerned. However, the experience of the present war seems to indicate that there is something in this view, and it is more than probable that in the future the single-man machine will become a recognised type for military purposes. The advantage of the single-man type is that the machine can be altogether smaller and more compact, it can be designed to possess, speed for speed, a higher degree of inherent stability, and so will fly itself, leaving the pilot quite free to make observations and notes. Beyond this it is more difficult to hit and may more easily escape observation; it is also better to manage when it comes to alighting in a difficult situation. Needless to say, the single-man type is not a fighting type, although for bomb-dropping and such like duties it seems clear that the weight of a second man in extra bombs would be of far more value than the man himself.
§ 100. Aircraft bases at High Altitude. Aeronautical tactics will present many fascinating problems and opportunities to the air-fleet commander of the future, entirely without parallel in the pre-existing Arms of the Service, and there will be ample scope for originality and resource. Take, for example, the operations of aircraft in a mountainous country such as the Alpine regions of Europe; the selection of aeroplane stations or bases at high altitude, and their employment to determine an ascendancy over an enemy less fortunately situated; the utilisation to their full extent of air-currents, etc. It must be remembered that an advantage in altitude can be always turned to account to give a temporary advantage in speed, as in the swoop of a bird of prey. We may look confidently to the wide employment of such swooping tactics in the future of aerial warfare. The advantage possessed by an air fleet having its base at high altitude, sometimes even some 6,000 ft, or 8,000 ft, above sea-level, will be very great; it will have the initial advantage of the upper berth, and this under some circumstances may result in the enemy fleet, or sections of it, being kept flying for long periods together at high altitude in order to avoid the possibility of being engaged in action at a disadvantage. Such a process might conceivably result in the wearing away of a hostile air fleet to such a degree as to determine its ultimate defeat.
- ↑ Perhaps the above is asking too much. When a fleet is of sufficient numerical strength it may be that a definite superiority in climbing power will not be necessary. Thus sections of the fleet may be told off to operate at various different altitudes, so that escape from one section will mean engagement by another. If the choice of altitude is thus left to the enemy, it is clear that the numerical superiority will need be overwhelming.
- ↑ The range of the armament in an aerial engagement is mainly a question of muzzle velocity, not calibre.