Aircraft in Warfare (1916)/Chapter 7
CHAPTER VII.
(October 16th, 1914)
ATTACK BY AEROPLANE ON AEROPLANE, THE FIGHTING MACHINE AND ITS ARMAMENT.
§ 43. Attack by Aeroplane on Aeroplane. In the present war the services of the Flying Corps have, in the main, been confined to scouting and reconnaissance in its various forms, the amount of work which has been done in this direction being very great; according to present reports, a mileage equivalent to many circuits of the globe has already been covered. So far the casualties have been slight, and the actual risk and danger are considered less than in the other combatant branches of the Service. The meaning of this evidently is that the methods of attack on aircraft have not kept pace with the development of the craft themselves. Considering the importance, from the enemy's point of view, of interfering with the operations of our aircraft (for from a modern standpoint to annihilate the aircraft of an enemy is virtually to deprive him of his power of vision), it is quite certain that the present conditions cannot last, and means will assuredly be found before the next great war, if not during the continance of the present war, by which the attack of aeroplane on aeroplane will be rendered far more deadly than at present, and the air forces of both combatants will be more highly organised to this end than is the case to-day.
It has already been remarked that attack on so swift and, in effect, on so small a moving target as an aeroplane is by no means an easy problem. We have already discussed the difficulties of attack from the ground, and it now remains to examine the problem of attack by air—i.e., attack by aeroplane on aeroplane.
At one time the author was disposed to be somewhat sceptical as to the possibility, or rather the general feasibility, of such a mode of attack. It seemed as though aeronauts might spend hours manoeuvring and firing, and between them blow away hundreds of pounds weight of ammunition without any decisive result. On closer consideration, however, it would appear that, provided one machine can, either by greater speed, or power of manoeuvre, force the other to close quarters, there are conditions (as when both machines are moving in the same direction), under which gun-fire (especially machine-gun fire) could be brought to bear with conclusive effect. We have already been regaled from time to time by the Press with florid descriptions of aeroplane fights in which pilots or observers were said to blaze away at each other with automatic pistols, and it has frequently been stated that the enemy has been brought down by this means. After careful inquiries in quarters believed to be well informed, the author is disposed to discredit these stories. Doubtless attempts have been made by one pilot, or aeronaut, on another by rifle and pistol fire, but there is not, so far as the author has been able to ascertain, any definite record of casualties resulting.[1]
§ 44. The Fighting Machine as a Separate Type. It is at present uncertain whether the scouting or reconnaissance machine will itself in the future be called upon to fight: the view has already been expressed in these articles that the long-distance machine or strategic scout should not in any sense be considered as a fighter, its speed and Plate VI.
_-_Plate_VI.png)
R.A.F. TYPE F.E.2. Deigned to carry gun weight 300 lbs. Wings interchangeable with B.E.2.
Speed: Max. 69 m/h. Climb 1,000 ft. in 3½ minutes. Designed and built in 1913.
power of rapidly putting on altitude alone form its natural and most appropriate means of defence. The tactical scout is not in the same position; its duties are of such a character that if it be driven by hostile aircraft away from its place of operation, it has for the time being ceased to fulfil its mission, and so either it must always operate with a protective force of fighting machines within call, or it must itself be armed, and be rendered capable of putting up a fight. In any case the tactical scout or machine for local reconnaissance will require to be furnished, to some extent at least, with both offensive and defensive armament. But it is by no means clear that it will require to be armed more heavily than may be sufficient to hold its own with the aircraft of the enemy engaged on similar duty, or than required to enable it to perform the minor acts of aggression against the enemy's land forces that fall to its lot.
Evidently it can be only a matter of time before the specialised fighting-machine is called into being. We may admit that the first and more immediate step will be to render the tactical reconnaissance type capable of taking the offensive, so that it may establish its ascendency over the similar craft of the enemy. But the struggle for supremacy in the air which must then ensue will call imperatively for something more powerful and efficient, a specialised and heavily-armed fighting-machine in fact. It is this type, the fighting machine of the future, that the author proposes to make the subject of present study, discussing primarily the factors upon which its armament and its usage, or tactical employment, depend. It may be taken that for the period during which the tactical scout is playing the double rôle of reconnaissance-machine and fighting-machine the main general considerations will apply.
§ 45. The Question of Armament; Treaty Restrictions. In the specification of a fighting type of aeroplane the first and foremost consideration is its means of attack. These fall into two broadly distinct categories: fire-arms, chief amongst which for the purpose in question is the machine-gun or mitrailleuse; and gravitational weapons, including bombs, hand-grenades, steel darts, etc.; the latter being mainly useful when attacking a terrestrial objective. Except when dealing with a dirigible or airship, gravitational weapons are but ill suited to the conditions of attack on aircraft. Light artillery may certainly be mounted on an aeroplane, but only the very smallest calibre—namely, the "1-pounder"—can be considered suitable for machines such as are built at the present day; even the mounting of a gun of this size is a matter of great difficulty. The only advantage obtained by the employment of a weapon of this character is in the fact that it is permissible to throw shell, high-explosive or otherwise, the use of which for smaller sizes of projectiles is prohibited by treaty obligation. Any explosive projectile of less than 1 lb, weight (more exactly 400 grammes, or 14 oz., about) is banned by the Declaration of St. Petersburg,[2] of 1868; the paragraph with which we are concerned reads:—"The contracting parties engage mutually to renounce in case of war amongst themselves the employment by their military or naval troops, of any projectile of a weight below 400 grammes which is either explosive or charged with fulminating or inflammable substances." This is reaffirmed in the text of an abortive declaration of the Brussels Conference of 1874. Article 13 (e): "The use of arms, projectiles, or material which may cause unnecessary suffering, as well as the use of the projectiles prohibited by the Declaration of St. Petersburg in 1868." In the Hague Conference of 1899. Article 23 (e), it is prohibited "To employ arms, projectiles, or material of a nature to cause superfluous injury." Also Article 60, Declaration ii.:—"The contracting parties agree to abstain from the use of bullets that expand or flatten easily in the human body, such as bullets with a hard envelope which does not entirely cover the core, or is pierced with incisions." In view of the fact that the Brussels Conference of 1874 was sterile, and that the Hague Declaration ii., Article 60, was not subscribed to by the British representative, the Declaration of St. Petersburg with its 14 oz, minimum for explosive projectiles is the only definite statement by which we are bound. However, the restriction as to the employment of dum-dum or expanding bullets appears to have received our tacit acquiescence, at least in so far as concerns warfare with other civilised States. There is also the rather indefinite statement of the Hague Conference of 1899, to which we have subscribed, to the effect that we shall not employ arms, projectiles, or material of a nature to cause superfluous injury. The subject of these restrictions will be taken up again in a later chapter; it is here sufficient to point to their existence, and to the fact that they considerably hamper and restrict the development of aircraft and counter-aircraft armament. There seems to be no proper reason why we should be compelled to use some hundreds of unsuitable projectiles, specially designed to afford the least possible injury to the struts, spars, etc., through which they pass, when a comparatively few expanding or explosive bullets would do vastly more injury, and result in a machine being incapacitated both in less time and at less expense. It cannot be supposed that if one of the nations at present at war were to inaugurate the practice of utilising, against aircraft, projectiles infringing the Declaration of St. Petersburg, there would be any great wave of indignation created in the world at large. If, for example, we were to find our aircraft being knocked about by such means, we need not imagine that we should receive much compensation in the way of international sympathy. The author is not for a moment suggesting that we should initiate any departure from the accepted usage of warfare in this respect; he is rather questioning the ethics of a procedure by which a country, whose obligations and responsibilities are as wide and as heavy as those of Great Britain, and whose traditions and the force of public opinion make solemn contracts binding, should become a signatory to agreements which are always liable to be (and sometimes are) signed by the other party with his tongue in his cheek. At the best the signing of restrictive agreements relating to the conduct of war may at some time after turn out to be no more or less than the drawing of a cheque on another's banking account—a cheque that will be honoured in another man's blood.
§ 46. The One-Pounder as an Aeroplane Gun. For the time being we will take the restrictions imposed by international agreement as though they were restrictions imposed by Nature, and accept the fact that for the throwing of explosive or inflammable projectiles the "one-pounder" is the smallest gun available. At present this offers considerable difficulty in the case of an aeroplane. In order to throw a 14 oz, projectile with a muzzle velocity of 1,700 ft.-sec, the weight of gun and its mountings, including suitable recoil mechanism, could not be much less than 1 cwt., and with 100 rounds of ammunition the total would be about 2½ cwt. Now this weight alone cannot be considered in any sense prohibitive; in fact, it is no more than most of the existing machines in service would be able to carry. But the difficulties of design are not confined to the weight problem; the gun would have a length from muzzle to breech of 4 ft, or 5 ft., in addition to about 1 ft, representing its movement on recoil, as permitted by the buffer mechanism. To accommodate such a weapon, with reasonable freedom in elevation and traverse, would almost require that the gun be designed first, and that the aeroplane be designed round it. The difficulties can only be properly appreciated by taking a drawing-board and paper and endeavouring to find a practicable solution. Beyond the initial difficulties of the problem, it is very doubtful whether it will be found to pay to attack a hostile aeroplane with so large a shell as required by the 14 oz, limit. If a thoroughly sensitive fuse were available, so that the shell would explode on impact with canvas, matters would wear a different aspect, for the wing spread of an aeroplane presents a target of respectable size. However, as things stand, with a total of only about 100 rounds at command, and so small and elusive a target, it is doubtful whether, save under very exceptional circumstances, it would pay to throw away ammunition in pursuit. If the problem be that of attacking a dirigible, it may be considered more hopeful; there is actually more to hit, besides the fact that the aeroplane, in the matter of speed, has the balloon always at a disadvantage; here again the importance of a sensitive impact fuse is paramount.
The necessity for being sparing in the use of ammunition must not be taken to mean (as sometimes represented) that there is no advantage in rapidity of fire, but rather the contrary, and any aeroplane armament gun must be essentially a quick-firer, if not actually automatic or semi-automatic; it is of vital importance that when the opportunity does occur, the utmost use should be made of it. When an aeroplane is within decisive range of its prey, it must be presumed that it isitself also under fire, and all the conditions discussed in the foregoing articles apply. If a machine, type A, has four times the rate of fire of another machine, type B, the machine A, so long as its ammunition holds out, is worth as much as two machines of the type B. In the case of the one-pounder now under discussion, this condition of the exhaustion of the ammunition is just the weak point which renders it doubtful whether under existing circumstances it is worth while seriously to consider the mounting of such a weapon. It is doubtful, also, whether a fully automatic gun of this calibre is admissible with aeroplanes of present-day dimensions, on account of the mean recoil reaction. This is approximately 1 lb, per shot per minute, or at a rate of 100 per minute, 100 lb.; a quantity that would still further hamper the designer in the arrangement of his gun position.
§ 47. The Machine-Gun; Importance of Rapid Fire. For the time being there is no doubt that the ordinary machine-gun is the most serviceable and effective weapon available. Taking, for example, the Lewis gun with its self-contained magazine, the weight of the weapon mounted in place is under 30 lb., and the service ammunition runs 17 to the pound. Assuming, as before, 2½ cwt, as the available total, and taking 4 lb, as the weight of a magazine of 47 rounds, it will be possible to carry some sixty magazines representing nearly 3,000 rounds. The usual manner of employing such a weapon on a moving target, as presented by an aeroplane in flight, is to fire by "bursts," each burst being sighted afresh and commonly consisting of some six or eight shots, so that the speed of fire never averages as high as that of which the gun is capable; thus the supply of ammunition above given would be sufficient for a continuous and hot engagement of about a quarter of an hour's duration. From the point of view of recoil the machine-gun is quite harmless; the mean recoil of the Lewis gun firing Mark VII, ammunition amounts to slightly less than 2.5 lb, per shot per second, or at 600 per minute the recoil reaction is about 25 lb.
§ 48. Rapid Fire. Machine-Guns Multiply Mounted. In view of the advantages of rapid fire, it would seem desirable to increase the speed of fire of the machine-gun to the maximum extent possible. When, on land, the obvious thing to do under similar circumstances would be to bring two guns into action, a similar course is not possible on a flying machine, owing to the weight of the additional gunner. An extra man must either mean the sacrifice of a couple of thousand rounds of ammunition or a couple of hours' petrol supply, neither of which alternatives can be entertained. The conditions indicate the mounting of machine-guns in pairs, or the design of double or triple-barrel guns, the breech actions of which would be independent, but so arranged that they could be fired one, two, or three at a time; by this means a "burst" of twenty-five or thirty bullets could be got off in less than one second. It may be found that a gun designed to take the 0.45 service revolver or automatic-pistol ammunition will be better suited to the conditions than the present weapon, in which the service rifle (Mark VII.) ammunition is employed. Such a gun would be far more handy, owing to the shortness of the cartridge, and would be furnished with a comparatively short barrel; also the magazine could be made of more compact form better to permit of the multiple-barrel design. Beyond the above, the shattering effect of the round-nose pistol bullet is known to be far greater than that of the 0.303 spitzer, so that greater injury will be inflicted on any spars or other structural members that may be hit. Incidentally, also, the stopping effect on pilot or gunner will be greater in the event of a shot getting home. In addition to the advantages enumerated, the 0.450 pistol ammunition weighs 21 to the pound, against the service rifle 17, which gives an addition of 25 per cent, to the number of rounds. When drawing on a limited supply of ammunition it is clearly necessary to select whatever is best suited to the work in hand.
Plate VII.
_-_Plate_VII.png)
R.A.F. TYPE R.E.5. An "R.E. Portable" Tent Pole
is shown used as Derrick for dismounting Engine
- ↑ Quite true at the date of the original article; the Press accounts were in no sense reliable. Intelligent anticipation is the usual designation.
- ↑ The signatories to this Declaration include representatives of the following:—Great Britain. Austria and Hungary. Belgium, Denmark, France, Greece, Italy, Netherlands, Persia, Portugal, Russia, Sweden and Norway, Switzerland, and Turkey. The German Confederation and semi-independent States were also signatories; but in view of the doctrines of modern Germany as touching the value of international treaties, her signature cannot be taken as meaning anything.