Allied Air Power Doctrine: Royal Air Force War Manual; Volume I - Chapter 4: The Fighting Services

General Consideration

1 . The full power of a nation can be exerted only when all its parts act in that close co-operation which is essential to success in war. This principle applies with particular force to the fighting services whose members should therefore broadly understand the potentialities and limitations of the other services as well as his own. The aim in war of the fighting services is referred to in chapter 1, paras. 3 to 7.

The Navy

2. The navy is responsible for the security of the sea communications of the Empire, and for the safety of all British territory against organized invasion from the sea. Aircraft take their part in naval operations in recon­naissance, observation of gun fire, and in attacking enemy vessels and aircraft bases from which to operate are essential to the navy and the co-operation of the other services may be necessary to secure and protect them.

3. In addition to its regular fighting ships a navy requires large numbers of miscellaneous craft for the maintenance of a fleet. A naval force comprises a variety of fighting ships, whose main features are briefly referred to in the following paras. 4 to 12.

4. Battleships. These combine the maximum amount of armament and protection with a high degree of mobility. Their primary function is the destruction of the enemy's battle fleet. Failing opportunity for this function they should be so disposed that they can threaten with destruction the enemy forces should they put to sea. Battleships, battle cruisers and cruisers may carry one or more aircraft on specially designed platforms or cata­pults.

5. Battle cruisers. These carry the same calibre guns as battleships but the number of guns and the protective armour is to some extent sacrificed to speed. They may in certain circumstances be employed in support of aircraft carriers.

6.Cruisers. These are high speed vessels of smaller size and of lighter armament than battle cruisers. Their main duties are the control of sea communications, reconnaissance by direct observation, and the guarding of the fleet against surprise. In fleet actions, among other duties they carry out torpedo attacks.

7. Destroyers. These are small and light vessels of superior speed. Their main weapon is the torpedo and their main function the attack against the enemy battle fleet. They have also a gun armament which is effective against their own kind and in combination against cruisers. Their defensive function in co-operation with cruisers is to screen the fleet when cruising and to ward off attacks by destroyers or submarines. They may also be employed for the destruction of disabled enemy vessels, laying smoke screens, mine-sweeping, attacking submarines and the protection of our own disabled vessels.

8. Submarines. The principal characteristics of sub-marines are their ability to operate unseen, to deliver a surprise attack and to evade action with superior forces. Submarines can act without tactical support, except fleet submarines whose primary function is to act as a tactical unit of the fleet and whose endurance when submerged is sacrificed for high surface speed. Sub-marines often carry out more efficiently than surface craft duties such as patrols in the vicinity of enemy bases, whether for reconnaissance or offence, defensive patrols in the vicinity of our own ports, attack and defence of trade, and mine-laying.

9. Aircraft carriers. The primary function of aircraft carriers is to provide aircraft for use before and during fleet actions. They are ships specially constructed to accommodate aircraft in hangars below their decks. Lifts transport the aircraft from the hangars to the upper decks, which are designed to allow aircraft to fly off and on. The dimensions of these lifts limit the size of aircraft which can be used. To enable the operation of flying off and on to be carried out without undue loss of position relating to the fleet, an aircraft carrier should have speed in excess of the full speed of the fleet.

10. Mining craft. These are cruisers, destroyers, submarines and other vessels specially equipped and employed to lay mines and so deny the free use of certain waters to the enemy. Shallow draft vessels are provided for sweeping up enemy mines or for locating mined areas. Trawlers and drifters also are used because they are available in numbers and have suitable fittings and personnel ; their relatively deep draught, however, is a disadvantage.

11. Monitors and gunboats. These are mostly shallow draft vessels of slow speed. The monitor has one or more heavy guns and has good under-water protection against torpedo attack, whilst the gunboat is generally unarmoured and is usually employed in inland water-ways. Both are primarily intended for bombardment of forts and works and for co-operating with the army in a combined operation.

12. Coastal motor boats. These are small motor-driven craft of high speed, limited endurance and suitable for use in fair weather only. They are armed with either torpedoes or depth charges and may also be used for laying mines or smoke screens.

The Army

13. An army comprises several different arms, each having its special characteristics and functions and each being dependent on the co-operation of the other. In battle, an army requires the co-operation of aircraft for reconnaissance, observation of gun-fire, protection against enemy aircraft, the attack of enemy headquarters, of enemy communications and, under certain conditions, of enemy troops. The special characteristics and functions of the several arms are briefly referred to in the following paras. 14 to 17.

14. Infantry. Whose main object is to close with the enemy and destroy him. The weapons of the infantry are the rifle and bayonet, Lewis gun, machine gun, and grenade. Though the movements of infantry are slow and the distance it can cover in one day is relatively small, it can move over almost any ground by day or night and can find cover more readily than the other arms. It can, within certain limits, be moved rapidly in motor vehicles or in transportation aircraft and so be brought fresh into action at distant points.

15. Cavalry and Mounted Rifles, (i) Compared with infantry (except when conveyed in mechanical transport), possess great mobility, but they require the conditions of mobile warfare for their full development of this characteristic. Cavalry is armed with sword, machine guns and rifles. Mounted Rifles have no swords and are therefore not equipped for " shock action."

(ii) Before the main armies meet, cavalry and other mobile troops are employed in advance of the slower moving columns, either to obtain for the latter liberty of action by protecting their march from interference or to gain detailed information about the enemy. The infor­mation gained by cavalry is complementary to that obtained by means of air reconnaissance because the former can establish the dispositions of the enemy in detail, can obtain identification by taking prisoners, and can maintain contact continuously. If atmospheric conditions or the nature of the country are unfavourable for air observation it may be necessary for the cavalry to carry out unaided the duty of reconnaissance.

(iii) In battle, cavalry is employed to protect flanks, to co-operate in turning movements, as a mobile reserve and, finally, to exploit the success of other arms or cover their retreat.

16. Artillery, (i) Is employed to break down opposition and to afford all possible support to the other arms. It is one of the principal means by which fire superiority is gained on the battle front. The difficulty of replen­ishing ammunition in the field and the short life of the more powerful weapons, however, sets a limit to the expenditure of ammunition. Artillery is divided broadly into guns and howitzers. Guns have a flat, and howitzers a curved trajectory. The various types of artillery are light, horse, field, medium, heavy, super-heavy and anti-aircraft. Artillery, under certain conditions, can engage targets both by day and night without observation but yet with accuracy.

(ii) Observation from the air enables artillery to engage with accuracy targets which are invisible from the ground. The artillery relies largely on observation from the air for counter-battery work and for registra­tion required for harassing fire as well as for the engage­ment of fleeting targets which are defiladed from ground observation.

(iii) Anti-aircraft guns assist our aircraft and provide protection against enemy aircraft. They are employed either independently or in co-operation with aircraft and searchlights. They are at present most effective against aircraft flying at medium altitudes. Their effective range and accuracy may however increase.

17. Armoured fighting vehicles. (i) These are employed both in self-contained armoured formations and also to assist and co-operate with the other arms. Armoured fighting vehicles possess the characteristics of fire power, mobility and armour. They are essentially weapons of offence which produce great moral effect. Their radius of action enables them to strike a blow not only against the flanks of a hostile force, but also against an enemy's headquarters and his rear services. The limiting factors at present are their visibility, vulnerability by shell fire and inability to operate under unsuitable conditions, e.g., deep water, deep cuttings, swamps, thick woods, and rocky mountainous country. The noise made by the engines and tracks is considerable and the latter make distinctive marks on ground which is not very hard.

(ii) Tanks can move across country ; they can, within certain definite limits cross trenches and surmount obstacles. They can crush wire and thus facilitate the advance of the infantry. They can destroy hostile tanks, anti-tank guns and machine guns as well as personnel.

(iii) Armoured cars are wheeled or semi-tracked vehicles having a high rate of speed on roads or across easily negotiated open country when the surface is mainly level and good. They are specially suitable for reconnaissance, protective operations and for operations involving extensive and continuous movement, either independently or in co-operation with cavalry. (For aircraft in co-operation with the army, see chapter XII.)

The Air Force

18. (i) The air force comprises several different classes of aircraft, each having its special characteristics and functions, such as bombing, fighting, co-operation with the navy or army and transportation.

(ii) The chief military characteristics of aircraft are their power of manoeuvre and penetration and their rapidity and freedom of movement and action within the limits of their range. Their ability to move in three dimensions confers the power to approach their objectives from almost any direction and from any height up to the limit of their ceiling without regard to any of the normal natural or artificial obstacles.

(iii) Their mobility and freedom of action outside their radius of action from their bases depend upon landing grounds being available. They can be speedily concen­trated owing to the rapidity with which they can move from one aerodrome to another and to their ability to operate from advanced landing grounds, returning to their bases when necessary. Aircraft cannot always operate efficiently for any long period from advanced landing grounds when separated from their workshops and stores. The limitations imposed upon aircraft operating from advanced landing grounds vary with the type and class employed.

Aircraft can operate within a short period of time against widely separated objectives ; they can vary their lines and methods of approach and they can disengage from one objective in order to operate tempor­arily against another, without affecting seriously the original plan. Their employment therefore offers wide scope for the effective use of surprise, and they can achieve a widespread moral effect out of proportion to their actual strength and capacity.

19. (i) The chief factors which tend to reduce the efficiency of aircraft are fog, low clouds, snowstorms, limited endurance, little power of self-protection when on land or sea, inability to maintain permanent contact with their objectives either for observation, offence or defence and the reduction in the scope of some of their activities during the hours of darkness.

(ii) The effect upon the employment of aircraft of the potentialities and limitations described above are dealt with in succeeding chapters.

20. Aircraft are still in the process of rapid technical development and improvement. In design, research is directed along defined lines towards the perfection of special types to carry out the special duties for which aircraft are required. They are : bombing, fighting, co-operation with the navy and army and transportation. Each of these duties, however, requires the provision of several classes of aircraft, each with specialized functions. Except in emergencies aircraft should be employed only on the duties for which they are designed.

21. Bomber aircraft. (i) Bomber aircraft vary in class from the single-engined with a light load and high perform­ance to the multi-engined with a heavy load and moderate performance. Apart from performance and endurance, the main difference between the classes is the advantage possessed by the multi-engined in the disposition of arma­ment and in increased facilities for navigation. The single-engined class, of high performance, may also be used for long-distance day reconnaissance. The multi-engined class is employed mainly for work at night ; certain classes, however, can be used for work either by day or night.

(ii) The bomb is the chief weapon of an air force and the principal means by which it may attain its aim in war.

The endurance and performance of bomber aircraft may vary according to the duty to be performed and the military load to be carried. For example, in carrying out an attack on a far distant objective it may be necessary to sacrifice part of the bomb load or other equipment in order to carry the requisite amount of fuel or, while operating against a close objective, it may be possible to cut down the fuel and increase the bomb load ; similarly, a bomber operating by day against a distant objective, unable to reduce its fuel weight, may have to reduce its bomb load in order to increase its performance. (See also para. 28 on radius of action.)

22. Fighter aircraft. (i) In order to carry out effec­tively sustained operations from the air, and to ensure for other forces as far as possible immunity from air attack, an air force must be dominant in its own element. The primary function of fighter aircraft is, therefore, to contribute to the attainment of air superiority by the destruction of enemy aircraft in the air, but they may also be used to carry out low altitude attacks on suitable objectives with bombs and machine gun fire.

(ii) The chief characteristics of fighters are high speed, high ceiling, quick climb and easy manoeuvrability. The single-seater class usually develops a more powerful volume of fire forward than the two-seater, but the latter by reason of its rear guns has certain tactical advantages over the former : however, for some purposes these advantages are off-set by the superior performance and power of surprise of the single-seater.

23. Transport aircraft used for transportation purposes, are similar to bombers of moderate performance except that they carry the minimum armament and their fuselages are specially constructed for the purpose of accommodating passengers and cargo.

24. (i) Co-operation aircraft (Navy). Aircraft for employment in co-operation with the navy from aircraft carriers require a clear all-round view and long endurance, and should be controllable at low speeds. They are re­stricted in size by the dimensions of the lifts and the capacity of the hangars of a carrier. The normal com­plement of a carrier includes fighter, reconnaissance and torpedo aircraft. The latter type operate also from shore bases. Aircraft for employment from shore bases are not so limited in size ; essential qualities are ability to alight on and take off from water, long endurance, and good facilities for navigation.

(ii) The flying-boat and float-plane are employed normally from shore bases. An effective mobile unit can be formed by embarking float-planes in a suitable parent ship from which they can be hoisted out and in board by means of a crane, in calm weather or sheltered waters, or launched from a catapult. The flying-boat can operate independently for short periods from a temporary base or sheltered anchorage. It is more seaworthy, has greater endurance and carries a larger crew than the float-plane.

25. Bomber and fighter aircraft not specially equipped for flying over the sea may also be called upon to co-operate with the navy within reasonable distance from shore bases.

26. (i) Co-operation aircraft (Army). The character­istics required of aircraft for employment in co-operation with the army are handiness of control, ability to operate from confined spaces and bad surfaces and a clear all-round view, especially downwards. These requirements are necessary when carrying out close and medium reconnaissance duties where detailed information of the enemy forces is sought.

(ii) Aircraft co-operating with the army may be called upon to carry out long-distance reconnaissance to procure early information on which the higher com­mand may base decisions ; medium reconnaissance to obtain information of the enemy's lines of advance, location of flanks and railway and road movements in concentration areas and close reconnaissances which are confined to the immediate front or battle zone of the opposing forces. They may also be required to carry out night reconnaissances, photographic reconnaissances, artillery reconnaissances and observation to discover and report the positions of hostile batteries or their concentration and movement, and the effect of artillery fire upon them. They may also be required for com­munication duties.

(iii) Bomber and fighter aircraft are normally provided as a contingent to land forces. Bomber aircraft assist land forces by bomb and machine gun attacks on suitable targets ; such targets may be any centres of military organization, communications or hostile concentrations, etc. Fighter aircraft attack enemy aircraft and so attain a degree of air superiority which will permit other aircraft to carry out, with the minimum of interference, the duties of close and medium reconnaissance. In an emergency, or at the decisive moment of a land battle, as for instance, during a retreat, they may also be used to attack troops, tanks, transport columns and other ground objectives with bomb and machine gun fire.

27. Lighter-than-air aircraft. Airships and kite balloons are lighter-than-air aircraft. (i) Airships have a wide radius of action and can carry heavy loads. They carry ballast which, if discharged, enables them to climb rapidly to high altitudes. They may be armed with machine gun or heavier armament, but owing to their size and construction, comparatively low speed and limited power of manceuvre, they are at present very vulnerable to attack by aeroplanes.

(ii) Kite balloons are held captive by a winch and cable and are able to remain stationary at altitudes of 6,000 ft. and over. They therefore provide suitable observation posts in connection with naval and military operations. Owing to their vulnerability to attack by aircraft they are normally defended by anti-aircraft guns and machine guns from the ground.

28. Radius of action. The radius of action of an air-craft is the greatest distance which it can fly alone, in calm air and in a straight line at any time while retaining enough fuel to return to its starting point. In estimating the radius over which an aircraft can act under conditions obtaining at any time, the following factors, in addition to weather conditions, must be taken into account :

(i) Time running up on the ground.

(ii) The reduction in speed and increase in con­sumption when aircraft are flying in formation.

(iii) The time to be spent over the target.

(iv) The average altitude during the flight.

(v) Load.

(vii) A reasonable allowance for fighting and detours.

(vii) Wind.