Owing to the fertility of inventors and the resultant multiplicity of
designs it is impossible to describe every type of heavier-than-air
machine which has been submitted to the exacting requirements of
military duty. The variety is infinite and the salient fact has already
been established that many of the models which have proved reliable and
efficient under normal conditions are unsuited to military operations.
The early days of the war enabled those of doubtful value to be
eliminated, the result being that those machines which are now in
use represent the survival of the fittest. Experience has furthermore
emphasised the necessity of reducing the number of types to the absolute
minimum. This weeding-out process is being continued and there is no
doubt that by the time the war is concluded the number of approved types
of aeroplanes of military value will have been reduced to a score or
less. The inconveniences and disadvantages arising from the utilisation
of a wide variety of different types are manifold, the greatest being
the necessity of carrying a varied assortment of spare parts, and
confusion in the repair and overhauling shops.
The methodical Teuton was the first to grasp the significance of these
drawbacks; he has accordingly carried standardisation to a high degree
of efficiency, as is shown in another chapter. At a later date France
appreciated the wisdom of the German practice, and within a short time
after the outbreak of hostilities promptly ruled out certain types of
machines which were regarded as unsuitable. In this instance the process
of elimination created considerable surprise, inasmuch as it involved an
embargo on the use of certain machines, which under peace conditions
had achieved an international reputation, and were held to represent the
finest expression of aeronautical science in France as far as aeroplane
developments are concerned.
Possibly the German machine which is most familiar, by name, to the
general public is the Taube, or, as it is sometimes called, the Etrich
monoplane, from the circumstance that it was evolved by the Austrian
engineer Igo Etrich in collaboration with his colleague Wels. These two
experimenters embarked on the study of dynamic flight contemporaneously
with Maxim, Langley, Kress, and many other well-known pioneers, but it
was not until 1908 that their first practical machine was completed.
Its success was instantaneous, many notable flights being placed to its
credit, while some idea of the perfection of its design may be gathered
from the fact that the machine of to-day is substantially identical
with that used seven years ago, the alterations which have been effected
meanwhile being merely modifications in minor details.
The design of this machine follows very closely the lines of a bird in
flight--hence its colloquial description, "Taube," or "dove." Indeed the
analogy to the bird is so close that the ribs of the frame resemble the
feathers of a bird. The supporting plane is shaped in the manner of
a bird's distended wing, and is tipped up at the rear ends to ensure
stability. The tail also resembles that of a bird very closely.
This aeroplane, especially the latest type, is very speedy, and it has
proved extremely reliable. It is very sharp in turning and extremely
sensitive to its rudder, which renders it a first-class craft for
reconnoitring duty. The latest machines are fitted with motors
developing from 120 to 150 horse-power.
The "Taube" commanded attention in Germany for the reason that it
indicated the first departure from the adherence to the French designs
which up to that time had been followed somewhat slavishly, owing to the
absence of native initiative.
The individuality of character revealed in the "Taube" appealed to the
German instinct, with the result that the machine achieved a greater
reputation than might have been the case had it been pitted against
other types of essentially Teutonic origin. The Taube was subsequently
tested both in France and Great Britain, but failed to raise an equal
degree of enthusiasm, owing to the manifestation of certain defects
which marred its utility. This practical experience tended to prove that
the Taube, like the Zeppelin, possessed a local reputation somewhat of
the paper type. The Germans, however, were by no means disappointed by
such adverse criticism, but promptly set to work to eliminate defects
with a view to securing an all-round improvement.
The most successful of these endeavours is represented in the
Taube-Rumpler aeroplane, which may be described as an improved edition
of Etrich's original idea. As a matter of fact the modifications were of
so slight, though important, a character that many machines generically
described as Taubes are in reality Rumplers, but the difference is
beyond detection by the ordinary and unpractised observer.
In the Rumpler machine the wings, like those of the Taube, assume
broadly the form and shape of those of the pigeon or dove in flight. The
early Rumpler machines suffered from sluggish control, but in the later
types this defect has been overcome. In the early models the wings were
flexible, but in the present craft they are rigid, although fitted with
tips or ailerons. The supporting truss beneath the wings, which was such
an outstanding feature of its prototype, has been dispensed with, the
usual I-beam longitudinals being used in its stead. The latest machines
fitted with 100-120 horse-power Mercedes motors have a fine turn of
speed, possess an enhanced ascensional effort, and are far simpler to
control.
Other German machines which are used in the military service are the
Gotha and the Albatross. The former is a monoplane, and here again
the influence of Etrich upon German aeroplane developments is strongly
manifested, the shape of the bird's wing being retained. In the Gotha
the truss which Etrich introduced is a prominent characteristic. The
Albatross is a biplane, but this craft has proved to be somewhat slow
and may be said to be confined to what might be described as the heavier
aerial military duties, where great endurance and reliability are
essential. As the war proceeds, doubtless Teuton ingenuity will
be responsible for the appearance of new types, as well as certain
modifications in the detail construction of the existing machines, but
there is every indication that the broad lines of Etrich's conception
will be retained in all monoplanes.
There is one point in which Germany has excelled. Wood is not employed
in the construction of these heavier-than-air craft. Steel and the
lighter tough alloys are exclusively used. In this way the minimum of
weight consistent with the maximum of strength policy is carried
out. Moreover the manufacture of component parts is facilitated and
accelerated to a remarkable degree by the use of metal, while the
tasks of fitting and repairing are notably expedited by the practice of
standardisation. Germany is also manifesting commendable enterprise in
the perfection of light powerful motors for these dynamic machines. The
latest types of explosion-motors range from 100 to 150 horse-power; the
advantages of these are obvious.
Upon the outbreak of hostilities the French possessed an enormous number
and variety of aeroplanes and this aerial fleet had been brought to
a high standard of organisation. The aerial fleet is sub-divided into
squadrons called "escadrilles," each of which comprises six machines and
pilots. These units are kept up to strength, wastage being made up from
reserves, so as to maintain the requisite homogeneity.
But ere the war had been in progress many weeks an official order was
issued forbidding the employment of the Bleriot, Deperdussin, Nieuport,
and R.E.P. monoplanes. Those which received official approval included
the Caudron, Henry, and Maurice Farman, Morane-Saulnier, and Voisin
machines.
This drastic order came somewhat as a thunderbolt, and the reason for
the decree has not been satisfactorily revealed. Suffice to say that in
one stroke the efficiency and numerical strength of the French aerial
navy were reduced very appreciably. For instance, it is stated that
there were thirty escadrilles of Bleriot monoplanes together with pilots
at the front, in addition to thirty mixed escadrilles of the other
prohibited types with their fliers. Moreover a round 33 escadrilles of
all the various types were in reserve. The effect of the military order
was to reduce the effective strength by no fewer than 558 aeroplanes.
Seeing that the French aerial force was placed at a great disadvantage
numerically by this action, there seems to be ample justification for
the hostile criticism which the decree of prohibition aroused in certain
circles, especially when it is remembered that there was not an equal
number of the accepted machines available to take the place of those
which had been ruled out of court. One effect of this decree was to
throw some 400 expert aviators upon the waiting list for the simple
reason that machines were unavailable. Some of the best aviation skill
and knowledge which France possesses were affected by the order. It
is stated that accomplished aviators, such as Vedrines, were unable to
obtain machines.
It will be seen that the ultimate effect of the French military decree
was to reduce the number of types to about four, each of which was
allotted a specific duty. But whereas three different bi-planes are on
the approved list there is only one monoplane--the Morane-Saulaier.
This machine, however, has a great turn of speed, and it is also able to
climb at a very fast pace. In these respects it is superior to the crack
craft of Germany, so that time after time the latter have refused battle
in the skies, and have hurried back to their lines.
The Morane-Saulnier is the French mosquito craft of the air and like the
insect, it is avowedly aggressive. In fact, its duties are confined to
the work of chasing and bringing down the enemy, for which work its high
manoeuvring capacity is excellently adapted. Its aggressive armament
comprises a mitrailleuse. Unfortunately, however, the factory
responsible for the production of this machine is at present handicapped
by the limitations of its manufacturing plant, which when pushed to the
utmost extent cannot turn out more than about ten machines per week. No
doubt this deficiency will be remedied as the war proceeds by extension
of the works or by allotting orders to other establishments, but at the
time of the decree the manufacturing capacity was scarcely sufficient to
make good the wastage, which was somewhat heavy.
As far as biplanes are concerned the Caudron is the fastest in flight
and is likewise extremely quick in manoeuvring. It is a very small
machine and is extremely light, but the fact that it can climb at the
rate of over 330 feet per minute is a distinct advantage in its favour.
It supplements the Morane-Saulnier monoplane in the specific duty of the
latter, while it is also employed for discovering the enemy's artillery
and communicating the range of the latter to the French and British
artillery. In this latter work it has played a very prominent part and
to it is due in no small measure that deadly accuracy of the artillery
of the Allies which has now become so famous. This applies especially
to those tactics, where the field artillery dashes up to a position,
discharges a number of rounds in rapid succession, or indulges in rafale
firing, and then limbering up, rushes away before the enemy can reply.
As is well known the Farman biplanes possess high endurance qualities.
They can remain aloft for many hours at a stretch and are remarkably
reliable. Owing to these qualities they are utilised for prolonged and
searching reconnoitring duties such as strategical reconnaissances as
distinct from the hurried and tactical reconnaissances carried out by
fleeter machines. While they are not so speedy as the monoplanes of the
German military establishment, endurance in this instance is preferable
to pace. A thorough survey of the enemy's position over the whole of
his military zone, which stretches back for a distance of 30 miles or so
from the outer line of trenches, is of incalculable value to a commander
who is contemplating any decisive movement or who is somewhat in doubt
as to the precise character of his antagonist's tactics.
The French aerial fleet has been particularly active in its work of
raiding hostile positions and submitting them to a fusillade of bombs
from the clouds. The machine which is allotted this specific task is
the Voisin biplane. This is due to the fact that this machine is able to
carry a great weight. It was speedily discovered that in bomb-raids
it is essential for an aeroplane to be able to carry a somewhat large
supply of missiles, owing to the high percentage of misses which attends
these operations. A raid by a machine capable of carrying only,
say, half-a-dozen projectiles, is virtually a waste of fuel, and
the endurance limitations of the fast machines reacts against their
profitable use in this work. On the other hand, the fact that the Voisin
machine is able to carry a large supply of bombs renders it an ideal
craft for this purpose; hence the official decision to confine it to
this work.
So far as the British efforts in aerial work are concerned there is no
such display of rigid selection as characterises the practice of the
French and German military authorities. Britain's position in the air
has been extensively due to private enterprise, and this is still being
encouraged. Moreover at the beginning of the war Britain was numerically
far inferior both to her antagonist and to her ally. Consequently it was
a wise move to encourage the private manufacture of machines which had
already established their value. The consequence is that a variety
of machines figure in the British aerial navy. Private initiative is
excellently seconded by the Government manufacturing aeroplane factory,
while the training of pilots is likewise being carried out upon a
comprehensive scale. British manufacture may be divided into two broad
classes--the production of aeroplanes and of waterplanes respectively.
Although there is a diversity of types there is a conspicuous
homogeneity for the most part, as was evidenced by the British raid
carried out on February 11-12, when a fleet of 34 machines raided the
various German military centres established along the coast of Flanders.
Considerable secrecy has been displayed by the British Government
concerning the types of machines that are being utilised, although
ample evidence exists from the producing activity of the various
establishments that all available types which have demonstrated their
reliability and efficiency are being turned to useful purpose. The Avro
and Sopwith warplanes with their very high speeds have proved remarkably
successful.
So far as manufacturing is concerned the Royal Aerial Factory may be
said to constitute the back bone of the British aerial fleet. This
factory fulfils various purposes. It is not only engaged in the
manufacture of machines, and the development of aeroplanes for specific
duties, but also carries out the inspection and testing of machines
built by private firms. Every machine is submitted to an exacting test
before it is passed into the service.
Three broad types of Government machines are manufactured at this
establishment. There is that designed essentially for scouting
operations, in which speed is the all-important factor and which is
of the tractor type. Another is the "Reconnoitring" machine
known officially as the "R.E." to-day, but formerly as the "B.E"
(Bleriot-Experimental), a considerable number of which are in
commission.
This machine is also of the tractor type, carrying a pilot and an
observer, and has a maximum speed of 40-50 miles per hour. If required
it can further be fitted with an automatic gun for defence and attack.
The third craft is essentially a fighting machine. Owing to the
introduction of the machine-gun which is fixed in the prow, with the
marksman immediately behind it, the screw is placed at the rear. The
pilot has his seat behind the gunner. The outstanding feature of these
machines is the high factor of safety, which attribute has astonished
some of the foremost aviation experts in the world.
Great Britain lagged behind her Continental rivals in the development
of the Fourth Arm, especially in matters pertaining to motive power.
For some time reliance was placed upon foreign light highspeed explosion
motors, but private enterprise was encouraged, with the result that
British Motors comparing favourably in every respect with the best
productions upon the Continent are now available. Development is still
proceeding, and there is every evidence that in the near future entire
reliance will be placed upon the native motor.
Undoubtedly, as the war progresses, many valuable lessons will be
learned which will exercise an important bearing upon the design
and construction of warplanes. The ordeals to which the machines are
submitted in military duties are far more severe than any imposed by the
conditions of commerce. Accordingly there is every indication that
the conflict upon the Continent will represent a distinctive epoch in
aeroplane design and construction. Many problems still await solution,
such as the capacity to hover over a position, and it is quite possible
that these complex and baffling questions will be settled definitely
as the result of operations in the field. The aeroplane has reached a
certain stage of evolution: further progress is virtually impossible
unless something revolutionary is revealed, perfected, and brought to
the practical stage.