Chapter XVIII · AIR CRAFT AND MOTOR VEHICLES IN WAR.

While other branches of the service have hundreds of years of precedents back of them, there is very little past experience to guide us in the use of air craft in war. Portable observation stations, captive balloons, and man-lifting kites still form part of the equipment of all modern armies, but the two principal classes of air craft today are air ships and aeroplanes.

That air craft will play a very important part in future wars is no longer questioned, but the development of both air ships and aeroplanes is proceeding so rapidly that it is difficult to say today what they will be capable of doing tomorrow. There are many possible uses for this new arm of the service, but a number of these are still largely matters of speculation. Others, however, are now well determined and these in themselves are of sufficient importance to require the adoption of air craft as an indispensable part of the equipment of any army.

There is a natural tendency on the part of those who are engaged in the development of a new instrument of war to exaggerate its power and minimize its limitations. Air craft at the present moment are capable of rendering most valuable service, and with the improvements that are bound to come, their value for military purposes will be greatly increased; but the claims of certain enthusiasts that aeroplanes and air ships have rendered cavalry obsolete and revolutionized the art of war have no foundation of fact.

Characteristics. Aeroplanes can travel about 350 miles and have a maximum speed of 80 or 90 miles an hour, or more. Service machines normally carry a pilot, an observer, and fuel and oil for from four to six hours. Aeroplanes can start and can land without assistance. They can be handled on the ground by three or four men. They can remain in the open for short periods without serious deterioration. When flying at normal working altitudes they are difficult to hit. Their chief use is for reconnaissance. On the other hand, aeroplanes cannot always be depended upon to be ready for work whenever they are needed. Compared with most war equipment, both aeroplanes and aeroplane engines are extremely fragile. Flying round an aerodrome where landings can be made on suitable ground, an average pilot will rarely injure his machine. But in war, pilots will be required to fly in all sorts of weather and will be forced to land on all sorts of ground in order to deliver promptly the information they have obtained. Minor breakages are bound to result and machines will be so badly strained that frequent overhauling will be necessary. Moreover, the engine, even with the best of care, should be overhauled after running twenty or twenty-five hours. It will be necessary, therefore, to provide large quantities of spare parts and to deliver these wherever needed. The care and repair of aeroplanes and engines require a highly trained commissioned and enlisted personnel.

Types are in active process of development and they vary with different nations. It seems certain that for the immediate future, no single type of aeroplane will suffice for all purposes but that air fleets will be composed of craft suited to different functions as is the case with sea craft. Examples of the variety of types are: The destroyer, a pusher biplane, armed with a machine gun in front and arranged to carry bombs and a wireless equipment but without armor. The battleplane, of great size, speed and offensive power, has a pilot with two soldiers each operating a machine gun that fires in all directions. The artillery spotter, carries armor, operates at a low height and has low speed; it carries an observer and a wireless equipment. The scout, a one man craft capable of great speed up to 80 or 90 miles per hour, or more, and great climbing power. It is equipped with rifle or revolver and is unarmored.

The principal problems remaining for solution in aeroplane development are concerned with obtaining a dependable motor and a propeller able to withstand the very great centrifugal stresses.

In several countries, and depending upon the nature of the duty, aeroplanes are organized and operate in squadrons of 6 to 8 machines. These squadrons are served by motor trucks that tow them from place to place. Some machines have wings that fold when being towed.

Air Ships. Air ships have a radius of action of about 1000 miles and a speed of from 40 to 50 miles an hour. They can remain in the air for many hours at a time, can hover over a selected spot, and can be used safely at night and in mist or rain. They afford a good field of view and can carry a number of observers. Their chief use is for distant reconnaissance which is greatly facilitated by their long range wireless equipment. Compared with aeroplanes, they offer an easy target and require a large number of trained men to handle them on the ground. The difficulty of maintaining them in the field makes it necessary to operate them from fixed bases established in time of peace.

Balloons are still used. Captive balloons are employed for tactical reconnaissance, and for observation of artillery fire; they are usually equipped with telephones.

Hydroaeroplanes are employed with navies, but have not come into extensive use.

Armor and armament. The weight of armor reduces the speed and the lifting capacity of aeroplanes. At present, armor is in general limited to a bullet proof seat for the pilot, and bullet proof protection to the fuel tank. Airships are able to carry more extensive armor. Aeroplanes are not very vulnerable to fire; to bring one to earth it is in general necessary to disable the pilot or to puncture the fuel tank. Even these accidents do not necessarily involve the destruction of the craft; pilots volplane successfully to earth without the use of the motor. Aeroplanes are frequently riddled with bullets without interfering with their operation. The principal armament of the aeroplane is the machine gun. The rifle and revolver are also used, as also small calibre guns. The armor and armament of a particular type depend upon the use to which that type is destined.

Duties. The primary duty is reconnaissance, both strategic and tactical. Reconnaissance consists usually in the location of troops and artillery positions.

Strategic reconnaissance by aeroplane is practicable for a distance of 150 miles; it endeavors to ascertain the position, strength, directions of movement, and dispositions of the larger elements of the enemy and also knowledge of the terrain in the theatre.

Tactical reconnaissance by air is used in both attack and defense. It is necessarily general in nature because the height of observation prevents close view. It endeavors to discover movements of the enemy, location of his reserve, his cavalry, artillery, movements of wagon and auto trains, camps, lines of communication, the nature of terrain, etc. Air reconnaissance extends and supplements that of cavalry but does not supplant it. Often verification of reconnaissance must be secured by actual contact.

The duty of reconnaissance involves the corresponding prevention of hostile reconnaissance. This duty has resulted in developing in most armies special types of fighting craft, the aim of which is to secure command of the air within the military theatre. There is in this a close analogy with the domination of the military theatre by sea power or by cavalry. Another important duty of air craft is that of directing artillery fire. For this purpose air craft are usually assigned one to each group of batteries, and operate directly under the orders of the artillery commander. Their information is conveyed by wireless, by smoke bombs, by visual signals, and by dropping messages. These methods are all in active process of development and vary with the different nations.

Hostile artillery in position, is discovered by the flash of its guns, by telltale wheel tracks to the artillery position and by activity in the position. For mid-range firing, aeroplanes can frequently direct the fire from a position directly above or even behind the friendly artillery.

Another duty of air craft is that of air raids. This duty is less important than the others. Like most other raids, those by aircraft are likely to have but little direct bearing on the military situation; but within special range they will continue to be performed. The objectives for air raids are capitals of states, military bases, hangars, lines of communication, depots, arsenals, etc. Raids are usually ineffective against troops or fortifications.

Another important function is the carrying of staff officers, of maps, dispatches, etc., as also reporting promptly the positions and movements of friendly troops.

Practicable heights for observation. Satisfactory reconnaissance from air craft requires low flying height and low speed. These two elements increase greatly the vulnerability of the craft. Air craft are comparatively safe from all kinds of fire, at 6000 feet elevation and are entirely safe at 10,000 feet. In clear weather the observer, at an elevation of about 5000 feet, can detect bodies of troops for a radius of four to six miles. Aeroplanes are practically safe from rifle fire at 2000 yards range or at an elevation of 3000 feet. They are reasonably safe from field artillery fire at 4000 yards range or at an elevation of approximately 4500 feet. It is difficult to reconnoiter in a wooded country. Timbered areas, therefore, have a new importance in the concealment they afford from overhead observation.

The safe heights above mentioned are in general too great to afford detailed observation, the necessity for close observation will, therefore, lead bold airmen to a closer approach to the enemy. By swerving, changing velocities, diving, soaring, etc., the airman reduces the risk involved in a close approach to the enemy. He will have added protection from hostile fire when he can soar directly over the anti aircraft guns, none of which is able to fire vertically upwards; also by operating where hostile projectiles will be likely in their fall to damage other hostile troops, and also by utilizing the protection of hills, etc. The vibration of the machine prevents satisfactory use of field glasses. The observer is restricted to observation with the naked eye.

Airships because of their greater size and slower and more regular motion, must remain at greater altitudes for safety than aeroplanes. Accordingly they will be less frequently employed for battlefield reconnaissance or wherever exposed to rapid fire of anti aircraft artillery.

Defensive measures. The principal defense against air craft is command of the air by superior air fleets. The tactics of air reconnaissance are, therefore, largely similar to those of cavalry or of sea power. The secondary defense against air craft consists of anti aircraft artillery. For elevations up to 3000 feet, the machine gun is effective. For greater elevations land forces must protect themselves by artillery. Special types of guns of great rapidity of fire are used as is also the standard light field types. The special types of anti aircraft artillery are usually employed in the protection of capitals, lines of communication, etc. They have a lesser application to mobile forces, because the need is less and the economy of road space greater. Light field artillery to be effective against air craft must be capable of firing at an elevation of 45 to 50 degrees. This calls for special types of trail and the necessity of digging pits for the trail.

Range finders are in general of little efficacy in locating the fast moving target. Artillery fire seeks its object in speed and volume of fire, rather than in attempted accuracy. Volume of fire may keep air craft away even if hits are few. Tracer shells emitting smoke are much used to assist observation of fire. To bring down an aeroplane it is almost absolutely necessary to disable the pilot or the fuel tank. The airship is much more vulnerable. The target is the gas bag, rather than the pilot.

Powers and limitations. From the very first it has been obvious that air craft would be of enormous value for all kinds of reconnaissance work. Some of their advantages for this purpose are:

1. Speed. It will often be possible for air craft to obtain in a few hours, information that it would require days to secure by any other means.

2. Ability to surmount both natural and artificial obstacles.

3. Ability to determine depth of enemy’s troops as well as front.

4. Having once obtained the desired information, it is comparatively easy to ascend to a reasonably safe altitude and bring the information back.

Some of the limitations of air craft in reconnaissance work are:

1. They can accomplish but little in heavy rains, gales, fog or darkness, though they are steadily improving in their ability to travel in heavy weather.

2. Inability to reconnoiter at night makes it impossible for air craft to keep in continuous touch with the enemy.

3. They cannot be depended upon to be ready for duty whenever they are needed.

4. Observing downwards from a considerable height, detailed knowledge of terrain cannot be obtained.

The European war has given the greatest stimulus to the development of aerial navigation. The art is doubtless destined to the widest expansion in the future. At present it has many limitations, and the absurd claims made for it should be carefully discounted. It has become another arm in warfare.

Like other inventions it is indispensable to the conduct of warfare. A relative preponderance in this arm confers on a belligerent an immense advantage.

(See also “Anti Aircraft Artillery,” Chap. VIII.)

The motor car, as lately applied to military purposes, has influenced practically every phase of campaign. As affecting tactics, it permits the rapid transport of troops over short distances where rail transport, even if available, might be slower than marching. The loading, dispatch and unloading are very rapid and flexible in arrangement. Even where the railroad is available, the motor car or truck is a valuable adjunct, provided suitable roads are available. The railroad can reach only its various stations, but with a system of good highways the motor vehicle can load or deliver at or very close to any designated point. Whereas a very slight accident will interrupt rail traffic the automobile can be stopped only by the destruction of the road (a comparatively rare occurrence) and sometimes even this will cause very little delay. The transportation begins at almost any point, such as camp, bivouac, or barrack, and is complete to the final destination without resorting to marches at either or both ends of the line.

The routing is not confined to any one prepared road bed. Moreover, the transport is not confined to short distances. The European war shows instances of transporting large bodies of troops over distances as great as 100 miles.

In effecting tactical concentrations of bodies of troops, such as reserves at critical points on the battle field itself, the motor car is very useful. The rapid concentration of forces at critical points of the field is the aim of all tactical operations and the secret of success in battle. The motor vehicle rapidly brings the troops to the desired point, fresh for action.

Motor vehicles are useful in the transport of troops pursuing a defeated enemy and correspondingly useful to the retreating force.

Heavy field artillery is utilizing motor transport to an ever increasing extent. The motor truck also lends itself admirably to use as swift, powerful armored cars, which are virtually small, movable forts. Motor trucks have demonstrated their ability to rapidly transport siege howitzers to threatened points along undefended portions of a coast line and thus greatly aid the mobile army in resisting landings. In operations on land the heaviest types of guns and howitzers are successfully transported.

For overseas operations the motor is useful, as it needs less room aboard ship and dispenses with much of the care and attention that animals require.

For Staff uses the motor is specially adapted to the transportation of general and staff officers over the field of battle. It also assists greatly in the distribution of orders; for this purpose the motorcycle also is much used. Officers can thus cover vastly greater territory than by the use of a horse and with practically no fatigue. The result is that officers of ripe experience and advanced age, whose failing physical powers would formerly have prevented their riding horses are now employed in the field. The scope of staff service is greatly increased.

For the Supply of an army the motor truck is particularly valuable. Its speed will vary with the condition of roads but on even mediocre roads it will cover daily several times the distance covered by the horse-drawn vehicle. It needs no halts for rest, operates in a country without regard to green forage areas, is hardier than the animal and is but little affected by weather. Nearly its total carrying capacity is available for cargo, whereas the necessity for carrying forage reduces that of the horse-drawn vehicle.

The motor truck is well adapted to use as a mobile soup kitchen; one small truck will serve a meal for 500 men.

Motor transportation now permits the army to operate at a distance from the base or railhead several times greater than is possible by the use of wagons or, conversely, it permits the supply of the army at moderate distances from a base with a much less number of vehicles; thus it shortens the total road distance of a force and tends to make armies less dependent for subsistence on the military theater. The increasing numerical strength of the modern army requires more and more independence of subsistence drawn from the country in which it operates.

In line of communication service, the armored car greatly assists in thwarting hostile attempts to cut the line.

The greater the capacity of motor trucks the more economical they are as carriers if the roads are satisfactory. In many theaters where American forces will continue to operate for some time to come, indifferent roads will be the rule; the economic size of the truck is accordingly restricted to a cargo capacity of about 1½ tons.

Motor trucks equipped with flanged steel wheels may be used on railroads in lieu of or in addition to the regular rolling stock. If both kinds of wheels (road and railroad) are carried, or interchangeable sets of demountable rims, the same truck may be used on both road and railroad. The change of wheels or rims can be made in a few minutes.

The motor vehicle is extensively employed in the ambulance service. In addition to its superiority from an humanitarian point of view, it has a very great capacity for the evacuation of sick and wounded, thus contributing to the increase of tactical efficiency of the army.

For the service of information, the motor is useful in patrolling; its speed and carrying capacity is great; it is in many ways less likely to attract notice than is a group of horsemen. It has been used for the prompt occupation of important points weakly defended. It is a useful adjunct to the aero service; aeroplanes organized into divisions of 7 or 8 machines are served by motor vehicles which transport the aeroplanes; the wings of the latter being folded for transport. The aeroplanes, which would otherwise be very vulnerable in camp, have thus some protection against the risk of sudden capture.

The motor car, in short, aids in strategic and tactical concentration of troops and heavy guns and in the defense of isolated points, lessens fatigue, and extends the theater of command, inspection and reconnaissance. It greatly increases the scope of operations by increasing the mobility of an army and making it largely independent of local food supplies; its humanitarian service is very satisfactory.

No army devoid of good motor transport service can thus hope to maintain itself against an adversary well equipped in that respect. All trained armies will be equipped with motors; therefore the motor will not permit a diminution of effort by a belligerent; to impose one’s will upon a trained adversary, the effort must in fact be greater than ever.

For efficiency of service, motors are employed where practicable in groups of the same type. This facilitates training of personnel, interchangeability of parts, repairs, etc. In armies generally, the field and combat wagons continue to use animal power.

The motor can enter every department of military activity, increasing the efficiency of operation therein. It is as applicable to campaign as to most other phases of modern life.