MAINTENANCE
CLEANLINESS.--The fabric must be kept clean and free from oil, as that
will rot it. To take out dirt or oily patches, try acetone. If that will
not remedy matters, then try petrol, but use it sparingly, as otherwise
it will take off an unnecessary amount of dope. If that will not remove
the dirt, then hot water and soap will do so, but, in that case, be
sure to use soap having no alkali in it, as otherwise it may injure the
fabric. Use the water sparingly, or it may get inside the planes and
rust the internal bracing wires, or cause some of the wooden framework
to swell.
The wheels of the undercarriage have a way of throwing up mud on to
the lower surface. This should, if possible, be taken off while wet.
It should never be scraped off when dry, as that may injure the fabric.
If dry, then it should be moistened before being removed.
Measures should be taken to prevent dirt from collecting upon any
part of the aeroplane, as, otherwise, excessive skin-friction will be
produced with resultant loss of flight speed. The wires, being greasy,
collect dirt very easily.
CONTROL CABLES.--After every flight the rigger should pass his hand over
the control cables and carefully examine them near pulleys. Removal of
grease may be necessary to make a close inspection possible. If only one
strand is broken the wire should be replaced. Do not forget the aileron
balance wire on the top surface.
Once a day try the tension of the control cables by smartly moving the
control levers about as explained elsewhere.
WIRES.--All the wires should be kept well greased or oiled, and in the
correct tension. When examining the wires, it is necessary to place the
aeroplane on level ground, as otherwise it may be twisted, thus throwing
some wires into undue tension and slackening others. The best way, if
there is time, is to pack the machine up into its "flying position."
If you see a slack wire, do not jump to the conclusion that it must
be tensioned. Perhaps its opposition wire is too tight, in which case
slacken it, and possibly you will find that will tighten the slack wire.
Carefully examine all wires and their connections near the propeller,
and be sure that they are snaked round with safety wire, so that the
latter may keep them out of the way of the propeller if they come
adrift.
The wires inside the fuselage should be cleaned and regreased about once
a fortnight.
STRUTS AND SOCKETS.--These should be carefully examined to see if any
splitting has occurred.
DISTORTION.--Carefully examine all surfaces, including the controlling
surfaces, to see whether any distortion has occurred. If distortion can
be corrected by the adjustment of wires, well and good; but if not, then
some of the internal framework probably requires replacement.
ADJUSTMENTS.--Verify the angles of incidence, dihedral, and stagger, and
the rigging position of the controlling surfaces, as often as possible.
UNDERCARRIAGE.--Constantly examine the alignment and fittings of the
undercarriage, and the condition of tyres and shock absorbers. The
latter, when made of rubber, wear quickest underneath. Inspect axles and
skids to see if there are any signs of them becoming bent. The wheels
should be taken off occasionally and greased.
LOCKING ARRANGEMENTS.--Constantly inspect the locking arrangements of
turnbuckles, bolts, etc. Pay particular attention to the control cable
connections, and to all moving parts in respect of the controls.
LUBRICATION.--Keep all moving parts, such as pulleys, control levers,
and hinges of controlling surfaces, well greased.
SPECIAL INSPECTION.--Apart from constantly examining the aeroplane with
reference to the above points I have made, I think that, in the case of
an aeroplane in constant use, it is an excellent thing to make a special
inspection of every part, say, once a week. This will take from two to
three hours according to the type of aeroplane. In order to carry it out
methodically, the rigger should have a list of every part down to the
smallest split-pin. He can then check the parts as he examines them,
and nothing will be passed over. This, I know from experience, greatly
increases the confidence of the pilot, and tends to produce good work
in the air.
WINDY WEATHER.--The aeroplane, when on the ground, should face the
wind; and it is advisable to lash the control lever fast, so that the
controlling surfaces may not be blown about and possibly damaged.
"VETTING" BY EYE.--This should be practised at every opportunity, and,
if persevered in, it is possible to become quite expert in diagnosing
by eye faults in flight efficiency, stability, and control.
The aeroplane should be standing upon level ground, or, better than
that, packed up into its "flying position."
Now stand in front of it and line up the leading edge with the main
spar, rear spar, and trailing edge. Their shadows can usually be seen
through the fabric. Allowance must, of course, be made for wash-in and
wash-out; otherwise, the parts I have specified should be parallel with
each other.
Now line up the centre part of the main-plane with the tail-plane. The
latter should be symmetrical with it. Next, sight each interplane front
strut with its rear strut. They should be parallel.
Then, standing on one side of the aeroplane, sight all the front struts.
The one nearest to you should cover all the others. This applies to the
rear struts also.
Look for distortion of leading edges, main and rear spars, trailing
edges, tail-plane, and controlling surfaces.
This sort of thing, if practised constantly, will not only develop
an expert eye for diagnosis of faults, but will also greatly assist in
impressing upon the memory the characteristics and possible troubles
of the various types of aeroplanes.
MISHANDLING ON THE GROUND.--This is the cause of a lot of unnecessary
damage. The golden rule to observe is, PRODUCE NO BENDING STRESSES.
Nearly all the wood in an aeroplane is designed to take merely the
stress of direct compression, and it cannot be bent safely. Therefore,
in packing an aeroplane up from the ground, or in pulling or pushing it
about, be careful to stress it in such a way as to produce, as far as
possible, only direct compression stresses. For instance, if it is
necessary to support the lifting surface, then the packing should be
arranged to come directly under the struts so that they may take the
stress in the form of compression for which they are designed. Such
supports should be covered with soft packing in order to prevent the
fabric from becoming damaged.
When pulling an aeroplane along, if possible, pull from the top of the
undercarriage struts. If necessary to pull from elsewhere, then do so by
grasping the interplane struts as low down as possible. Never pull by
means of wires.
Never lay fabric-covered parts upon a concrete floor. Any slight
movement will cause the fabric to scrape over the floor with resultant
damage.
Struts, spars, etc., should never be left about the floor, as in such
position they are likely to become scored. I have already explained the
importance of protecting the outside fibres of the wood. Remember also
that wood becomes distorted easily. This particularly applies to
interplane struts. If there are no proper racks to stand them in, then
the best plan is to lean them up against the wall in as near a vertical
position as possible.
TIME.--Learn to know the time necessary to complete any of the various
rigging jobs. This is really important. Ignorance of this will lead
to bitter disappointments in civil life; and, where Service flying is
concerned, it will, to say the least of it, earn unpopularity with
senior officers, and fail to develop respect and good work where men
are concerned.
THE AEROPLANE SHED.--This should be kept as clean and orderly as
possible. A clean, smart shed produces briskness, energy, and pride of
work. A dirty, disorderly shed nearly always produces slackness and poor
quality of work, lost tools, and mislaid material.
[Illustration]
[Illustration]
GLOSSARY
_The numbers at the right-hand side of the page indicate the parts
numbered in the preceding diagrams._
=Aeronautics=--The science of aerial navigation.
=Aerofoil=--A rigid structure, of large superficial area relative to
its thickness, designed to obtain, when driven through the air at an
angle inclined to the direction of motion, a reaction from the air
approximately at right angles to its surface. Always cambered when
intended to secure a reaction in one direction only. As the term
"aerofoil" is hardly ever used in practical aeronautics, I have,
throughout this book, used the term SURFACE, which, while academically
incorrect, since it does not indicate thickness, is the term usually
used to describe the cambered lifting surfaces, _i.e._, the "planes"
or "wings," and the stabilizers and the controlling aerofoils.
=Aerodrome=--The name usually applied to a ground used for the practice
of aviation. It really means "flying machine," but is never used in that
sense nowadays.
=Aeroplane=--A power-driven aerofoil fitted with stabilizing and
controlling surfaces.
=Acceleration=--The rate of change of velocity.
=Angle of Incidence=--The angle at which the "neutral lift line" of
a surface attacks the air.
=Angle of Incidence, Rigger's=--The angle the chord of a surface makes
with a line parallel to the axis of the propeller.
=Angle of Incidence, Maximum=--The greatest angle of incidence at which,
for a given power, surface (including detrimental surface), and weight,
horizontal flight can be maintained.
=Angle of Incidence, Minimum=--The smallest angle of incidence at which,
for a given power, surface (including detrimental surface), and weight,
horizontal flight can be maintained.
=Angle of Incidence, Best Climbing=--That angle of incidence at which an
aeroplane ascends quickest. An angle approximately halfway between the
maximum and optimum angles.
=Angle of Incidence, Optimum=--The angle of incidence at which the
lift-drift ratio is the highest.
=Angle, Gliding=--The angle between the horizontal and the path along
which an aeroplane, at normal flying speed, but not under engine power,
descends in still air.
=Angle, Dihedral=--The angle between two planes.
=Angle, Lateral Dihedral=--The lifting surface of an aeroplane is said
to be at a lateral dihedral angle when it is inclined upward towards its
wing-tips.
=Angle, Longitudinal Dihedral=--The main surface and tail surface are
said to be at a longitudinal dihedral angle when the projections of their
neutral lift lines meet and produce an angle above them.
=Angle, Rigger's Longitudinal Dihedral=--Ditto, but substituting "chords"
for "neutral lift lines."
=Angle, Pitch=--The angle at any given point of a propeller, at which
the blade is inclined to the direction of motion when the propeller is
revolving but the aeroplane stationary.
=Altimeter=--An instrument used for measuring height.
=Air-Speed Indicator=--An instrument used for measuring air pressures or
velocities. It consequently indicates whether the surface is securing
the requisite reaction for flight. Usually calibrated in miles per hour,
in which case it indicates the correct number of miles per hour at only
one altitude. This is owing to the density of the air decreasing with
increase of altitude and necessitating a greater speed through space to
secure the same air pressure as would be secured by less speed at a
lower altitude. It would be more correct to calibrate it in units of air
pressure. [1]
=Air Pocket=--A local movement or condition of the air causing an
aeroplane to drop or lose its correct attitude.
=Aspect-Ratio=--The proportion of span to chord of a surface.
=Air-Screw (Propeller)=--A surface so shaped that its rotation about an
axis produces a force (thrust) in the direction of its axis. [2]
=Aileron=--A controlling surface, usually situated at the wing-tip,
the operation of which turns an aeroplane about its longitudinal axis;
causes an aeroplane to tilt sideways. [3]
=Aviation=--The art of driving an aeroplane.
=Aviator=--The driver of an aeroplane.
=Barograph=--A recording barometer, the charts of which can be calibrated
for showing air density or height.
=Barometer=--An instrument used for indicating the density of air.
=Bank, to=--To turn an aeroplane about its longitudinal axis (to tilt
sideways) when turning to left or right.
=Biplane=--An aeroplane of which the main lifting surface consists of a
surface or pair of wings mounted above another surface or pair of wings.
=Bay=--The space enclosed by two struts and whatever they are fixed to.
=Boom=--A term usually applied to the long spars joining the tail of a
"pusher" aeroplane to its main lifting surface. [4]
=Bracing=--A system of struts and tie wires to transfer a force from one
point to another.
=Canard=--Literally "duck." The name which was given to a type of
aeroplane of which the longitudinal stabilizing surface (_empennage_)
was mounted in front of the main lifting surface. Sometimes termed
"tail-first" aeroplanes, but such term is erroneous, as in such a design
the main lifting surface acts as, and is, the _empennage_.
=Cabre=--To fly or glide at an excessive angle of incidence; tail down.
=Camber=--Curvature.
=Chord=--Usually taken to be a straight line between the trailing and
leading edges of a surface.
=Cell=--The whole of the lower surface, that part of the upper surface
directly over it, together with the struts and wires holding them
together.
=Centre (Line) of Pressure=--A line running from wing-tip to wing-tip,
and through which all the air forces acting upon the surface may be
said to act, or about which they may be said to balance.
=Centre (Line) of Pressure, Resultant=--A line transverse to the
longitudinal axis, and the position of which is the resultant of the
centres of pressure of two or more surfaces.
=Centre of Gravity=--The centre of weight.
=Cabane=--A combination of two pylons, situated over the fuselage, and
from which the anti-lift wires are suspended. [5]
=Cloche=--Literally "bell." Is applied to the bell-shaped construction
which forms the lower part of the pilot's control lever in a Bleriot
monoplane, and to which the control cables are attached.
=Centrifugal Force=--Every body which moves in a curved path is urged
outwards from the centre of the curve by a force termed "centrifugal."
=Control Lever=--A lever by means of which the controlling surfaces are
operated. It usually operates the ailerons and elevator. The
"joy-stick." [6]
=Cavitation, Propeller=--The tendency to produce a cavity in the air.
=Distance Piece=--A long, thin piece of wood (sometimes tape) passing
through and attached to all the ribs in order to prevent them from
rolling over sideways. [7]
=Displacement=--Change of position.
=Drift= (_of an aeroplane as distinct from the propeller_)--The horizontal
component of the reaction produced by the action of driving through the
air a surface inclined upwards and towards its direction of motion
_plus_ the horizontal component of the reaction produced by the
"detrimental" surface _plus_ resistance due to "skin-friction."
Sometimes termed "head-resistance."
=Drift, Active=--Drift produced by the lifting surface.
=Drift, Passive=--Drift produced by the detrimental surface.
=Drift= (_of a propeller_)--Analogous to the drift of an aeroplane.
It is convenient to include "eddies" and "cavitation" within this term.
=Drift, to=--To be carried by a current of air; to make leeway.
=Dive, to=--To descend so steeply as to produce a speed greater than the
normal flying speed.
=Dope, to=--To paint a fabric with a special fluid for the purpose of
tightening and protecting it.
=Density=--Mass of unit volume; for instance, pounds per cubic foot.
=Efficiency=--
Output
------
Input.
=Efficiency= (_of an aeroplane as distinct from engine and propeller_)--
Lift and Velocity
---------------------------
Thrust (= aeroplane drift).
=Efficiency, Engine=--
Brake horse-power
----------------------
Indicated horse-power.
=Efficiency, Propeller=--
Thrust horse-power
--------------------------------
Horse-power received from engine
(= propeller drift).
NOTE.--The above terms can, of course, be expressed in foot-pounds. It
is then only necessary to divide the upper term by the lower one to find
the measure of efficiency.
=Elevator=--A controlling surface, usually hinged to the rear of the
tail-plane, the operation of which turns an aeroplane about an axis
which is transverse to the direction of normal horizontal flight. [8]
=Empennage=--See "Tail-plane."
=Energy=--Stored work. For instance, a given weight of coal or petroleum
stores a given quantity of energy which may be expressed in foot-pounds.
=Extension=--That part of the upper surface extending beyond the span of
the lower surface. [9]
=Edge, Leading=--The front edge of a surface relative to its normal
direction of motion. [10]
=Edge, Trailing=--The rear edge of a surface relative to its normal
direction of motion. [11]
=Factor of Safety=--Usually taken to mean the result found by dividing
the stress at which a body will collapse by the maximum stress it will be
called upon to bear.
=Fineness= (_of stream-line_)--The proportion of length to maximum width.
=Flying Position=--A special position in which an aeroplane must be placed
when rigging it or making adjustments. It varies with different types of
aeroplanes. Would be more correctly described as "rigging position."
=Fuselage=--That part of an aeroplane containing the pilot, and to which
is fixed the tail-plane. [12]
=Fin=--Additional keel-surface, usually mounted at the rear of an
aeroplane. [13]
=Flange= (_of a rib_)--That horizontal part of a rib which prevents it
from bending sideways. [14]
=Flight=--The sustenance of a body heavier than air by means of its action
upon the air.
=Foot-pound=--A measure of work representing the weight of 1 lb. raised
1 foot.
=Fairing=--Usually made of thin sheet aluminium, wood, or a light
construction of wood and fabric; and bent round detrimental surface in
order to give it a "fair" or "stream-like" shape. [15]
=Gravity=--Is the force of the Earth's attraction upon a body. It
decreases with increase of distance from the Earth. See "Weight."
=Gravity, Specific=--
Density of substance
--------------------
Density of water.
Thus, if the density of water is 10 lb. per unit volume, the same
unit volume of petrol, if weighing 7 lb., would be said to have a
specific gravity of 7/10, _i.e._, 0.7.
=Gap= (_of an aeroplane_)--The distance between the upper and lower
surfaces of a biplane. In a triplane or multiplane, the distance between
any two of its surfaces. [16]
=Gap, Propeller=--The distance, measured in the direction of the thrust,
between the spiral courses of the blades.
=Girder=--A structure designed to resist bending, and to combine lightness
and strength.
=Gyroscope=--A heavy circular wheel revolving at high speed, the effect of
which is a tendency to maintain its plane of rotation against disturbing
forces.
=Hangar=--An aeroplane shed.
=Head-resistance=--Drift. The resistance of the air to the passage of
a body.
=Helicopter=--An air-screw revolving about a vertical axis, the direction
of its thrust being opposed to gravity.
=Horizontal Equivalent=--The plan view of a body whatever its attitude
may be.
=Impulse=--A force causing a body to gain or lose momentum.
=Inclinometer=--A curved form of spirit-level used for indicating the
attitude of a body relative to the horizontal.
=Instability=--An inherent tendency of a body, which, if the body is
disturbed, causes it to move into a position as far as possible away
from its first position.
=Instability, Neutral=--An inherent tendency of a body to remain in the
position given it by the force of a disturbance, with no tendency to
move farther or to return to its first position.
=Inertia=--The inherent resistance to displacement of a body as distinct
from resistance the result of an external force.
=Joy-Stick=--See "Control Lever."
=Keel-Surface=--Everything to be seen when viewing an aeroplane from the
side of it.
=King-Post=--A bracing strut; in an aeroplane, usually passing through a
surface and attached to the main spar, and from the end or ends of which
wires are taken to spar, surface, or other part of the construction in
order to prevent distortion. When used in connection with a controlling
surface, it usually performs the additional function of a lever, control
cables connecting its ends with the pilot's control lever. [17]
=Lift=--The vertical component of the reaction produced by the action
of driving through the air a surface inclined upwards and towards its
direction of motion.
=Lift, Margin of=--The height an aeroplane can gain in a given time and
starting from a given altitude.
=Lift-Drift Ratio=--The proportion of lift to drift.
=Loading=--The weight carried by an aerofoil. Usually expressed in pounds
per square foot of superficial area.
=Longeron=--The term usually applied to any long spar running length-ways
of a fuselage. [18]
=Mass=--The mass of a body is a measure of the quantity of material in it.
=Momentum=--The product of the mass and velocity of a body is known as
"momentum."
=Monoplane=--An aeroplane of which the main lifting surface consists of
one surface or one pair of wings.
=Multiplane=--An aeroplane of which the main lifting surface consists of
numerous surfaces or pairs of wings mounted one above the other.
=Montant=--Fuselage strut.
=Nacelle=--That part of an aeroplane containing the engine and/or pilot
and passenger, and to which the tail-plane is not fixed. [19]
=Neutral Lift Line=--A line taken through a surface in a forward direction
relative to its direction of motion, and starting from its trailing
edge. If the attitude of the surface is such as to make the said line
coincident with the direction of motion, it results in no lift, the
reaction then consisting solely of drift. The position of the neutral
lift line, _i.e._, the angle it makes with the chord, varies with
differences of camber, and it is found by means of wind-tunnel research.
=Newton's Laws of Motion=--1. If a body be at rest, it will remain at
rest; or, if in motion, it will move uniformly in a straight line until
acted upon by some force.
2. The rate of change of the quantity of motion (momentum) is
proportional to the force which causes it, and takes place in the
direction of the straight line in which the force acts. If a body be
acted upon by several forces, it will obey each as though the others
did not exist, and this whether the body be at rest or in motion.
3. To every action there is opposed an equal and opposite reaction.
=Ornithopter (or Orthopter)=--A flapping wing design of aircraft intended
to imitate the flight of a bird.
=Outrigger=--This term is usually applied to the framework connecting the
main surface with an elevator placed in advance of it. Sometimes applied
to the "tail-boom" framework connecting the tail-plane with the main
lifting surface. [20]
=Pancake, to=--To "stall."
=Plane=--This term is often applied to a lifting surface. Such application
is not quite correct, since "plane" indicates a flat surface, and the
lifting surfaces are always cambered.
=Propeller=--See "Air-Screw."
=Propeller, Tractor=--An air-screw mounted in front of the main lifting
surface.
=Propeller, Pusher=--An air-screw mounted behind the main lifting surface.
=Pusher=--An aeroplane of which the propeller is mounted behind the main
lifting surface.
=Pylon=--Any V-shaped construction from the point of which wires are
taken.
=Power=--Rate of working. [21]
=Power, Horse=--One horse-power represents a force sufficient to raise
33,000 lb. 1 foot in a minute.
=Power, Indicated Horse=--The I.H.P. of an engine is a measure of the
rate at which work is done by the pressure upon the piston or pistons,
as distinct from the rate at which the engine does work. The latter
is usually termed "brake horse-power," since it may be measured by an
absorption brake.
=Power, Margin of=--The available quantity of power above that necessary
to maintain horizontal flight at the optimum angle.
=Pitot Tube=--A form of air-speed indicator consisting of a tube with open
end facing the wind, which, combined with a static pressure or suction
tube, is used in conjunction with a gauge for measuring air pressures or
velocities. (_No. 1 in diagram._)
=Pitch, Propeller=--The distance a propeller advances during one
revolution supposing the air to be solid.
=Pitch, to=--To plunge nose-down.
=Reaction=--A force, equal and opposite to the force of the action
producing it.
=Rudder=--A controlling surface, usually hinged to the tail, the operation
of which turns an aeroplane about an axis which is vertical in normal
horizontal flight; causes an aeroplane to turn to left or right of the
pilot. [22]
=Roll, to=--To turn about the longitudinal axis.
=Rib, Ordinary=--A light curved wooden part mounted in a fore and aft
direction within a surface. The ordinary ribs give the surface its
camber, carry the fabric, and transfer the lift from the fabric to the
spars. [23]
=Rib, Compression=--Acts as an ordinary rib, besides bearing the stress of
compression produced by the tension of the internal bracing wires. [24]
=Rib, False=--A subsidiary rib, usually used to improve the camber of the
front part of the surface. [25]
=Right and Left Hand=--Always used relative to the position of the pilot.
When observing an aeroplane from the front of it, the right hand side of
it is then on the left hand of the observer.
=Remou=--A local movement or condition of the air which may cause
displacement of an aeroplane.
=Rudder-Bar=--A control lever moved by the pilot's feet, and operating
the rudder. [26]
=Surface=--See "Aerofoil."
=Surface, Detrimental=--All exterior parts of an aeroplane including
the propeller, but excluding the (aeroplane) lifting and (propeller)
thrusting surfaces.
=Surface, Controlling=--A surface the operation of which turns an
aeroplane about one of its axes.
=Skin-Friction=--The friction of the air with roughness of surface. A form
of drift.
=Span=--The distance from wing-tip to wing-tip.
=Stagger=--The distance the upper surface is forward of the lower surface
when the axis of the propeller is horizontal.
=Stability=--The inherent tendency of a body, when disturbed, to return to
its normal position.
=Stability, Directional=--The stability about an axis which is vertical
during normal horizontal flight, and without which an aeroplane has no
natural tendency to remain upon its course.
=Stability, Longitudinal=--The stability of an aeroplane about an axis
transverse to the direction of normal horizontal flight, and without
which it has no tendency to oppose pitching and tossing.
=Stability, Lateral=--The stability of an aeroplane about its longitudinal
axis, and without which it has no tendency to oppose sideways rolling.
=Stabilizer=--A surface, such as fin or tail-plane, designed to give an
aeroplane inherent stability.
=Stall, to=--To give or allow an aeroplane an angle of incidence greater
than the "maximum" angle, the result being a fall in the lift-drift
ratio, the lift consequently becoming less than the weight of the
aeroplane, which must then fall, _i.e._, "stall" or "pancake."
=Stress=--Burden or load.
=Strain=--Deformation produced by stress.
=Side-Slip, to=--To fall as a result of an excessive "bank" or "roll."
=Skid, to=--To be carried sideways by centrifugal force when turning to
left or right.
=Skid, Undercarriage=--A spar, mounted in a fore and aft direction, and
to which the wheels of the undercarriage are sometimes attached. Should
a wheel give way the skid is then supposed to act like the runner of a
sleigh and to support the aeroplane. [28]
=Skid, Tail=--A piece of wood or other material, orientable, and fitted
with shock absorbers, situated under the tail of an aeroplane in order
to support it upon the ground and to absorb the shock of alighting.
[28_a_]
=Section=--Any separate part of the top surface, that part of the bottom
surface immediately underneath it, with their struts and wires.
=Spar=--Any long piece of wood or other material.
=Spar, Main=--A spar within a surface and to which all the ribs are
attached, such spar being the one situated nearest to the centre of
pressure. It transfers more than half the lift from the ribs to the
bracing. [29]
=Spar, Rear=--A spar within a surface, and to which all the ribs are
attached, such spar being situated at the rear of the centre of pressure
and at a greater distance from it than is the main spar. It transfers
less than half of the lift from the ribs to the bracing. [30]
=Strut=--Any wooden member intended to take merely the stress of direct
compression.
=Strut, Interplane=--A strut holding the top and bottom surfaces
apart. [31]
=Strut, Fuselage=--A strut holding the _fuselage longerons_ apart. It
should be stated whether top, bottom, or side. If side, then it should
be stated whether right or left hand. _Montant_. [32]
=Strut, Extension=--A strut supporting an "extension" when not in
flight. It may also prevent the extension from collapsing upwards during
flight. [33]
=Strut, undercarriage=-- [33_a_]
=Strut, Dope=--A strut within a surface, so placed as to prevent the
tension of the doped fabric from distorting the framework. [34]
=Serving=--To bind round with wire, cord, or similar material. Usually
used in connection with wood joints and wire cable splices.
=Slip, Propeller=--The pitch less the distance the propeller advances
during one revolution.
=Stream-Line=--A form or shape of detrimental surface designed to produce
minimum drift.
=Toss, to=--To plunge tail-down.
=Torque, Propeller=--The tendency of a propeller to turn an aeroplane
about its longitudinal axis in a direction opposite to that in which the
propeller revolves.
=Tail-Slide=--A fall whereby the tail of an aeroplane leads.
=Tractor=--An aeroplane of which the propeller is mounted in front of the
main lifting surface.
=Triplane=--An aeroplane of which the main lifting surface consists of
three surfaces or pairs of wings mounted one above the other.
=Tail-Plane=--A horizontal stabilizing surface mounted at some distance
behind the main lifting surface. _Empennage_. [36]
=Turnbuckle=--A form of wire-tightener, consisting of a barrel into each
end of which is screwed an eyebolt. Wires are attached to the eyebolts
and the required degree of tension is secured by means of rotating the
barrel.
=Thrust, Propeller=--See "Air-Screw."
=Undercarriage=--That part of an aeroplane beneath the _fuselage_ or
_nacelle_, and intended to support the aeroplane when at rest, and to
absorb the shock of alighting.
=Velocity=--Rate of displacement; speed.
=Volplane=--A gliding descent.
=Weight=--Is a measure of the force of the Earth's attraction (gravity)
upon a body. The standard unit of weight in this country is 1 lb., and
is the force of the Earth's attraction on a piece of platinum called
_the standard pound_, deposited with the Board of Trade in London. At
the centre of the Earth a body will be attracted with equal force in
every direction. It will therefore have no weight, though its mass is
unchanged. Gravity, of which weight is a measure, decreases with
increase of altitude.
=Web= (_of a rib_)--That vertical part of a rib which prevents it from
bending upwards. [37_a_]
=Warp, to=--To distort a surface in order to vary its angle of incidence.
To vary the angle of incidence of a controlling surface.
=Wash=--The disturbance of air produced by the flight of an aeroplane.
=Wash-in=--An increasing angle of incidence of a surface towards its
wing-tip. [38]
=Wash-out=--A decreasing angle of incidence of a surface towards its
wing-tip. [39]
=Wing-tip=--The right or left-hand extremity of a surface. [40]
=Wire=--A wire is, in Aeronautics, always known by the name of its
function.
=Wire, Lift or Flying=--A wire opposed to the direction of lift, and used
to prevent a surface from collapsing upward during flight. [41]
=Wire, Anti-lift or Landing=--A wire opposed to the direction of gravity,
and used to sustain a surface when it is at rest. [42]
=Wire, Drift=--A wire opposed to the direction of drift, and used to
prevent a surface from collapsing backwards during flight.
=Wire, Anti-drift=--A wire opposed to the tension of a drift wire, and
used to prevent such tension from distorting the framework. [44]
=Wire, Incidence=--A wire running from the top of an interplane strut
to the bottom of the interplane strut in front of or behind it. It
maintains the "stagger" and assists in maintaining the angle of
incidence. Sometimes termed "stagger wire." [45]
=Wire, Bracing=--Any wire holding together the framework of any part of
an aeroplane. It is not, however, usually applied to the wires described
above unless the function performed includes a function additional to
those described above. Thus, a lift wire, while strictly speaking a
bracing wire, is not usually described as one unless it performs the
additional function of bracing some well-defined part such as the
undercarriage. It will then be said to be an "undercarriage bracing lift
wire." It might, perhaps, be acting as a drift wire also, in which case
it will then be described as an "undercarriage bracing lift-drift
wire." It should always be stated whether a bracing wire is (1) top,
(2) bottom, (3) cross, or (4) side. If a "side bracing wire," then it
should be stated whether right- or left-hand.
=Wire, Internal Bracing=--A bracing wire (usually drift or anti-drift)
within a surface.
=Wire, Top Bracing=--A bracing wire, approximately horizontal and situated
between the top longerons of fuselage, between top tail booms, or at the
top of similar construction. [46]
=Wire, Bottom Bracing=--Ditto, substituting "bottom" for "top." [47]
=Wire, Side Bracing=--A bracing wire crossing diagonally a side bay of
fuselage, tail boom bay, undercarriage side bay or centre-section side
bay. This term is not usually used with reference to incidence wires,
although they cross diagonally the side bays of the cell. It should be
stated whether right- or left-hand. [48]
=Wire, Cross Bracing=--A bracing wire, the position of which is diagonal
from right to left when viewing it from the front of an aeroplane. [49]
=Wire, Control Bracing=--A wire preventing distortion of a controlling
surface. [50]
=Wire, Control=--A wire connecting a controlling surface with the pilot's
control lever, wheel, or rudder-bar. [51]
=Wire, Aileron Gap=--A wire connecting top and bottom ailerons. [52]
=Wire, Aileron Balance=--A wire connecting the right- and left-hand top
ailerons. Sometimes termed the "aileron compensating wire." [53]
=Wire, Snaking=--A wire, usually of soft metal, wound spirally or tied
round another wire, and attached at each end to the framework. Used to
prevent the wire round which it is "snaked" from becoming, in the event
of its displacement, entangled with the propeller.
=Wire, Locking=--A wire used to prevent a turnbuckle barrel or other
fitting from losing its adjustment.
=Wing=--Strictly speaking, a wing is one of the surfaces of an
ornithopter. The term is, however, often applied to the lifting surface
of an aeroplane when such surface is divided into two parts, one being
the left-hand "wing," and the other the right-hand "wing."
=Wind-Tunnel=--A large tube used for experimenting with surfaces and
models, and through which a current of air is made to flow by artificial
means.
=Work=--Force × displacement.
=Wind-Screen=--A small transparent screen mounted in front of the pilot
to protect his face from the air pressure.
Types of Aeroplanes.
[Illustration: Plate I.]
The first machine to fly--of which there is anything like authentic
record--was the Ader "Avion," after which the more notable advances were
made as shown above.
[Illustration: Plate II.]
The Henri Farman was the first widely used aeroplane. Above are shown
the chief steps in its development.
[Illustration: Plate III.]
THE AVRO.--The aeroplane designed and built by Mr. A. V. Roe was the
first successful heavier-than-air flying machine built by a British
subject. Mr. Roe's progress may be followed in the picture, from his
early "canard" biplane, through various triplanes, with 35 J.A.P. and 35
h.p. Green engines, to his successful tractor biplane with the same 35
h.p. Green, thence through the "totally enclosed" biplane 1912, with 60
h.p. Green, to the biplane 1913-14, with 80 h.p. Gnome.
[Illustration: Plate IV.]
THE SOPWITH LAND-GOING BIPLANES.--The earliest was a pair of Wright
planes with a fuselage added. Next was the famous tractor with 80 h.p.
Gnome. Then the "tabloid" of 1913, which set a completely new fashion
in aeroplane design. From this developed the Gordon-Bennett racer shown
over date 1914. The gun-carrier was produced about the same time, and
the later tractor biplane in a development of the famous 80 h.p. but
with 100 h.p. monosoupape Gnome.
[Illustration: Plate V.]
THE MAURICE FARMAN.--First, 1909, the 50-60 h.p. Renault and coil-spring
chassis. 1910, the same chassis with beginning of the characteristic
bent-up skids. 1911 appeared the huge French Military Trials 3-seater;
also the round-ended planes and tails and "Henry" type wheels. This
developed, 1912, into the square-ended planes and upper tail, and long
double-acting ailerons of the British Military Trials. The 1913 type had
two rectangular tail-planes and better seating arrangements, known
affectionately as the "mechanical cow"; the same year came the first
"shorthorn," with two tail-planes and a low nacelle. This finally
developed into the carefully streamlined "shorthorn" with the raised
nacelle and a single tail-plane.
[Illustration: Plate VI.]
THE SHORT "PUSHERS."--In 1909 came the semi-Wright biplane, with 35 h.p.
Green, on which Mr. Moore-Brabazon won the "Daily Mail's" £1000 prize
for the first mile flight on a circuit on a British aeroplane. Then the
first box-kite flown by Mr. Grace at Wolverhampton. Later the famous
"extension" type on which the first Naval officers learned to fly. Then
the "38" type with elevator on the nacelle, on which dozens of R.N.A.S.
pilots were taught.
[Illustration: Plate VII.]
SHORT TRACTORS, 1911-1912.--They were all co-existent, but the first was
the "tractor-pusher" (bottom of picture). Then came the "twin-tractor
plus propeller" (at top). A development was the "triple-tractor" (on the
right), with two 50 h.p. Gnomes, one immediately behind the other under
the cowl, one driving the two chains, the other coupled direct. Later
came the single-engined 80 h.p. tractor (on the left), the original of
the famous Short seaplanes.
[Illustration: Plate VIII.]
THE VICKERS MACHINES: First the Vickers-R.E.P. of 1911, which developed
into the full-bodied No. V. with R.E.P. engine, then the Military Trials
"sociable" with Viale engine, and so to the big No. VII with a 100 h.p.
Gnome. Contemporary with the No. V and No. VI were a number of school
box-kites of ordinary Farman type, which developed into the curious
"pumpkin" sociable, and the early "gun 'bus" of 1913. Thence arrived the
gun-carrier with 100 h.p. monosoupape Gnome.
[Illustration: Plate IX.]
THE BRISTOL AEROPLANES.--First, 1910, Farman type box-kites familiar to
all early pupils. Then the miniature Maurice-Farman type biplane of the
"Circuit of Britain." Contemporaneous was the "floating tail" monoplane
designed by Pierre Prier, and after it a similar machine with fixed
tail. Then came the handsome but unfortunate monoplane designed by
M. Coanda for the Military Trials, 1912.
[Illustration: Plate X.]
THE BRISTOL TRACTORS.--Late 1912 came the round fuselaged tractor, with
Gnome engine, designed by Mr. Gordon England for Turkey. 1912-13 came
the biplane built onto the Military Trials monoplane type fuselage,
also with a Gnome, designed by M. Coanda for Roumania. Then the
Renault-engined Coanda tractor 1913, followed by 80 h.p. Gnome-engined
scout, designed by Messrs. Barnwell and Busteed, which with Gnomes,
le Rhones and Clergets, has been one of the great successes. Almost
contemporary was the two-seater Bristol.
[Illustration: Plate XI.]
THE MARTINSYDES.--1909, first experimental monoplane built with small
4-cylinder engine. J.A.P.-engined machine, 1910, followed by the
Gnome-engined machine, 1911. 1912, first big monoplane with Antoinette
engine was built, followed by powerful Austro-Daimler monoplane, 1913.
Then came the little Gnome-engined scout biplanes, 1914, some with,
some without, skids.
[Illustration: Plate XII.]
THE CURTISS BIPLANES.--In 1909 came the "June-bug," the united product
of Glen Curtiss, Dr. Graham Bell, and J. A. D. McCurdy. Then the
box-kite type, 1909, on which Mr. Curtiss won the Gordon-Bennett Race at
Reims. Next the "rear-elevator" pusher, 1912, followed by first tractor,
1913, with an outside flywheel. All purely Curtiss machines to that
date had independent ailerons intended to get away from Wright patents.
Following these came tractors with engines varying from 70 to 160 h.p.,
fitted with varying types of chassis. All these have ordinary ailerons.
[Illustration: Plate XIII.]
THE BLERIOT (1).--The first engine-driven machine was a "canard"
monoplane. Then came the curious tractor monoplanes 1908-1909, in
order shown. Famous "Type XI" was prototype of all Bleriot successes.
"Type XII" was never a great success, though the ancestor of the popular
"parasol" type. The big passenger carrier was a descendant of this type.
[Illustration: Plate XIV.]
THE BLERIOT (2):--1910, "Type XI," on which Mr. Grahame-White won
Gordon-Bennett Race, with a 14-cylinder 100 h.p. Gnome. 1911 came the
improved "Type XI," with large and effective elevator flaps. On this
type, with a 50 h.p. Gnome, Lieut. de Conneau (M. Beaumont) won
Paris-Rome Race and "Circuit of Britain." Same year saw experimental
"Limousine" flown by M. Legagneux, and fast but dangerous "clipped-wing"
Gordon-Bennett racer with the fish-tail, flown by Mr. Hamel. About the
same time came the fish-tailed side-by-side two-seater, flown by Mr.
Hamel at Hendon and by M. Perreyon in 1912 Military Trials. 1911, M.
Bleriot produced the 100 h.p. three-seater which killed M. Desparmets in
French Military Trials. 1912-13, M. Bleriot produced a quite promising
experimental biplane, and a "monocoque" monoplane in which the passenger
faced rearward.
[Illustration: Plate XV.]
THE BLERIOT (3)--1912 tandem two-seater proved one of the best machines
of its day. 1913 "canard" lived up to its name. A "pusher" monoplane was
built in which the propeller revolved on the top tail boom. This machine
came to an untimely end, with the famous pilot, M. Perreyon. 1912
"tandem" was developed in 1914 into the type shown in centre; almost
simultaneously "parasol" tandem appeared. 1914, M. Bleriot built a
monoplane embodying a most valuable idea never fully developed. The
engine tanks and pilot were all inside an armoured casing. Behind them
the fuselage was a "monocoque" of three-ply wood bolted onto the armour.
And behind this all the tail surfaces were bolted on as a separate unit.
[Illustration: Plate XVI.]
THE CAUDRON.--1910, came the machine with ailerons and a 28 h.p. Anzani.
1911 this was altered to warp control and a "star" Anzani was fitted.
From this came the 35 h.p. type of 1912, one of the most successful
of school machines. Small fast monoplane, 1912, was never further
developed. 1913 appeared the familiar biplanes with 80 h.p. Gnomes,
and 5-seater with 100 h.p. Anzani for French "Circuit of Anjou." 1914
produced the "scout" biplane which won at Vienna. 1915 appeared the
twin-engined type, the first successful "battle-plane."
[Illustration: Plate XVII.]
THE DEPERDUSSIN.--In 1911 the little monoplane with a Gyp. engine.
Then the Gnome-engined machine of the "Circuit of Europe." In 1912 came
the Navy's machine with 70 h.p. Gnome, and Prevost's Gordon-Bennett
"Bullet," 135 miles in the hour. The last was the British-built
"Thunder-Bug," familiar at Hendon.
[Illustration: Plate XVIII.]
THE BREGUET.--First to fly was the complicated but business-like machine
of 1909. Then came the record passenger carrier, 1910 (which lifted 8
passengers). 1911 the French Military Trials machine with geared-down
100 h.p. Gnome appeared. 1912 produced the machine with 130 h.p. Salmson
engine on which the late Mr. Moorhouse flew the Channel with Mrs.
Moorhouse and Mr. Ledeboer as passengers; also the machine with 130 h.p.
horizontal Salmson, known as the "Whitebait." The last before the war
was the rigid wing machine with 200 h.p. Salmson.
[Illustration: Plate XIX.]
THE CODY.--First the Military Experiment of 1908, with an Antoinette
engine, then improved type 1909 with a Green engine. Next the
"Cathedral," 1910, with a Green engine, which won Michelin Prize. In
1911 "Daily Mail" Circuit machine, also with a Green, won the Michelin.
This was modified into 1912 type which won Military Competition and
£5,000 in prizes, with an Austro-Daimler engine, and later the Michelin
Circuit Prize, again with a Green. 1912 the only Cody Monoplane was
built. 1913 a modified biplane on which the great pioneer was killed.
[Illustration: Plate XX.]
THE NIEUPORT.--The first Nieuport of 1909 was curiously like a monoplane
version of a Caudron. In 1910 came the little two-cylinder machine with
fixed tail-plane and universally jointed tail. In 1911 the French Trials
machine was built with 100 h.p. 14 cylinder Gnome, and is typical of
this make. Also the little two-cylinder record breaker. A modification
of 1913 was the height record machine of the late M. Legagneux.
[Illustration: Plate XXI.]
THE R.E.P. MONOPLANES.--First came the curious and highly interesting
experiments of 1907, 1908, 1909, and 1910. 1910-1911, the World's
Distance Record breaker was produced; after it, the "European Circuit,"
all with R.E.P. engines. In 1913-14 came the French military type with
Gnome engine and finally the "parasol," 1915.
[Illustration: Plate XXII.]
THE MORANE: First the European Circuit and Paris-Madrid type. Then the
1912 types, with taper wing and modern type wing. The 1913 types, the
"clipped wing," flown by the late Mr. Hamel, one of the standard tandem
types now in use. About the same time came the "parasol." 1914-15 came
a little biplane like a Nieuport, and the "destroyer" type with a round
section body, flown by Vedrines.
[Illustration: Plate XXIII.]
THE VOISIN.--1908, the first properly controlled flight on a European
aeroplane was made on a Voisin of the type shown with fixed engine.
Then followed the record breaker of 1909 with a Gnome engine. In 1909
also the only Voisin tractor was produced. 1910 the Paris-Bordeaux type
was built; 1911 the amphibious "canard" and the "military" type with
extensions, and the type without an elevator. 1913 came the type with
only two tail-booms and a geared-down engine, which developed into the
big "gun" machine with a Salmson engine.
[Illustration: Plate XXIV.]
THE HANRIOT AND PONNIER MONOPLANES.--In 1909 came the first Hanriot with
50 h.p. 6-cylinder Buchet engine, and in 1910 the famous "Henrietta"
type with E.N.Vs. and stationary Clergets. 1911 came the Clerget
two-seater entered in French Military Trials, and 1912 the 100 h.p.
Hanriot-Pagny monoplane which took part in British Military Trials.
Sister machines of the same year were the single seater with 50 h.p.
Gnome and the 100 h.p. Gnome racer with stripped chassis. In 1913 the
Ponnier-Pagny racing monoplane with 160 h.p. Le Rhone competed in the
Gordon-Bennett race, doing about 130 miles in the hour. The 60 h.p.
Ponnier biplane was the first successful French scout tractor biplane.
[Illustration: Plate XXV.]
THE WRIGHT BIPLANE.--The first power flights were made, 1903, on a
converted glider fitted with 16 h.p. motor. The prone position of the
pilot will be noted. By 1907 the machine had become reasonably practical
with 40 h.p. motor. On this the first real flying in the world was done.
In 1910 the miniature racing Wright was produced; also the type with a
rear elevator in addition to one in front. Soon afterwards the front
elevator disappeared, and the machine became the standard American
exhibition and school machine for four years. In 1915 a machine with
enclosed fuselage was produced.
[Illustration: Plate XXVI.]
THE BLACKBURN MONOPLANES.--In 1909 was built the curious four-wheeled
parasol-type machine with 35 h.p. Green engine and chain transmission,
on which flying was done at Saltburn. In 1911 the Isaacson-engined
machine was built, together with a 50 h.p. Gnome single-seater on which
Mr. Hucks started in the Circuit of Britain race. In 1912 another 50
h.p. single-seater was built on which a good deal of school work was
done. A more advanced machine appeared in 1913 and a two-seater with
80 h.p. Gnome did a great deal of cross-country work in 1913-14.
[Illustration: Plate XXVII.]
In 1908 the first Antoinette monoplane was produced by MM. Gastambide
and Mengin. Then followed a machine with central skids, a single wheel,
and wing skids. In 1909 came the machine with four-wheeled chassis and
ailerons and later an improved edition which reverted to the central
skid idea. On this M. Latham made his first cross-channel attempt.
The next machine shed the wing skids and widened its wheelbase.
During 1910-11 the ailerons vanished, warp control was adopted and the
king-post system of wing-bracing was used. In 1911 the curious machine
with streamlined "pantalette" chassis, totally enclosed body and
internal wing-bracing, was produced for French Military Trials. In 1912
the three-wheeled machine was used to a certain extent in the French
Army. Then the type disappeared.
[Illustration: Plate XXVIII.]
In 1908 and 1909 detached experimental machines in various countries
attained a certain success. The late Capt. Ferber made a primitive
tractor biplane 1908. The Odier-Vendome biplane was a curious bat-winged
pusher biplane built 1909. The tailless Etrich monoplane, built in
Austria, 1908, was an adaptation of the Zanonia leaf. M. Santos-Dumont
made primitive parasol type monoplanes known as "Demoiselles," in which
bamboo was largely used. 1909 type is seen above. A curious steel
monoplane was built by the late John Moisant, 1909. The twin-pusher
biplane, built by the Barnwell Bros. in Scotland, made one or two
straight flights in 1909. The Clement-Bayard Co. in France constructed
in 1909 a biplane which did fairly well. Hans Grade, the first German
to fly, made his early efforts on a "Demoiselle" type machine, 1908.
[Illustration: Plate XXIX.]
In 1910 a number of novel machines were produced. The Avis with Anzani
engine was flown by the Hon. Alan Boyle. Note the cruciform universally
jointed tail. The Goupy with 50 h.p. Gnome was an early French tractor,
notable for its hinging wing-tips. The Farman was a curious "knock-up"
job, chiefly composed of standard box-kite fittings. The Sommer with
50 h.p. Gnome was a development of the box-kite with a shock-breaking
chassis. The Savary, also French, was one of the first twin tractors to
fly. The model illustrated had an E.N.V. engine. Note position of the
rudders on the wing tips. The Austrian Etrich was the first successful
machine of the Taube class ever built.
[Illustration: Plate XXX.]
INTERESTING MACHINES, 1910.--The Werner monoplane with E.N.V. engine,
combined shaft and chain drive, was a variant of the de Pischoff. The
Macfie biplane was a conventional biplane with 50 h.p. Gnome and useful
originalities. The Valkyrie monoplane, another British machine, was a
"canard" monoplane with propeller behind the pilot and in front of main
plane. The Weiss monoplane was a good British effort at inherent
stability. The Tellier monoplane was a modified Bleriot with Antoinette
proportions. The Howard Wright biplane was a pusher with large lifting
monoplane tail. The Dunne biplane was another British attempt at
inherent stability. The Jezzi biplane was an amateur built
twin-propeller.
[Illustration: Plate XXXI.]
SOME INTERESTING MACHINES, 1911.--The Compton-Paterson biplane was very
similar to the early Curtiss pusher; it had a 50 h.p. Gnome. The Sloan
bicurve was a French attempt at inherent stability with 50 h.p. Gnome
and tractor screw. The Paulhan biplane was an attempt at a machine for
military purposes to fold up readily for transport. The Sanders was
a British biplane intended for rough service. The Barnwell monoplane
was the first Scottish machine to fly; it had a horizontally opposed
Scottish engine. The Harlan monoplane was an early German effort; note
position of petrol tank.
[Illustration: Plate XXXII.]
The Clement-Bayard monoplane, 1911, was convertible into a tractor
biplane. The standard engine was a 50 h.p. Gnome. The machine was
interesting, but never did much. The Zodiac was one of the earliest
to employ staggered wings. With 50 h.p. Gnome engine it was badly
underpowered, so never did itself justice. The Jezzi tractor biplane,
1911, was a development of an earlier model built entirely by Mr. Jezzi,
an amateur constructor. With a low-powered J.A.P. engine it developed
an amazing turn of speed, and it may be regarded as a forerunner of the
scout type and the properly streamlined aeroplane. The Paulhan-Tatin
monoplane, 1911, was a brilliant attempt at high speed for low power;
it presented certain advantages as a scout. A 50 h.p. Gnome, fitted
behind the pilot's seat in the streamlined fuselage, was cooled through
louvres. The propeller at the end of the tail was connected with the
engine by a flexible coupling. This machine was, in its day, the fastest
for its power in the world, doing 80 miles per hour. Viking 1 was a twin
tractor biplane driven by a 50 h.p. Gnome engine through chains. It was
built by the author at Hendon in 1912.
[Illustration: Plate XXXIII.]
Much ingenuity was exerted by the French designers in 1911 to
produce machines for the Military Trials. Among them was the 100 h.p.
Gnome-Borel monoplane with a four-wheeled chassis, and the Astra
triplane with a 75 h.p. Renault engine. This last had a surface of about
500 square feet and presented considerable possibilities. Its principal
feature was its enormous wheels with large size tyres as an attempt to
solve difficulties of the severe landing tests. The Clement-Bayard
biplane was a further development of the Clement-Bayard monoplane;
the type represented could be converted into a monoplane at will. The
Lohner Arrow biplane with the Daimler engine was an early German tractor
biplane built with a view to inherent stability, and proved very
successful. The Pivot monoplane was of somewhat unconventional French
construction, chiefly notable for the special spring chassis and pivoted
ailerons at the main planes; this pivoting had nothing to do with the
name of the machine, which was designed by M. Pivot.
[Illustration: Plate XXXIV.]
The Flanders monoplane, 1912, with 70 h.p. Renault engine, was one of
the last fitted with king-post system of wing bracing. The Flanders
biplane entered for British Military Trials. Notable features: the
highly staggered planes, extremely low chassis and deep fuselage. Also,
the upper plane was bigger in every dimension than the lower; about
the first instance of this practice. The Bristol biplane, with 100 h.p.
Gnome engine, was also entered for the Trials, but ultimately withdrawn.
The Mars monoplane, later known as the "D.F.W.," was a successful
machine of Taube type with 120 h.p. Austro-Daimler engine. The building
of the engine into a cowl, complete with radiator in front, followed car
practice very closely. The tail of the monoplane had a flexible trailing
edge; its angle of incidence could be varied from the pilot's seat,
so that perfect longitudinal balance was attained at all loadings and
speeds. The Handley-Page monoplane, with 70 h.p. Gnome engine, was an
early successful British attempt at inherent stability.
[Illustration: Plate XXXV.]
The Sommer monoplane, with 50 h.p. Gnome, was a 1911-12 machine; it did
a good deal of cross-country flying. The Vendome monoplane of 1912, also
with 50 h.p. Gnome engine, was notable chiefly for its large wheels
and jointed fuselage, which enabled the machine to be taken down for
transport. The Savary biplane took part in the French Military Trials,
1911. It had a four-cylinder Labor aviation motor. Notable features are
twin chain-driven propellers, rudders between the main planes, the broad
wheel-base and the position of the pilot. The Paulhan triplane, which
also figured in the French Military Trials, was a development of the
Paulhan folding biplane. It had a 70 h.p. Renault engine. For practical
purposes it was a failure. The R.E.P. biplane, with 60 h.p. R.E.P.
engine, was a development of the famous R.E.P. monoplanes. Its spring
chassis, with sliding joints, marked an advance. Like the monoplanes,
it was built largely of steel.
[Illustration: Plate XXXVI.]
In 1912 came the first really successful Handley-Page monoplane, with
50 h.p. Gnome engine. The Short monoplane, was built generally on
Bleriot lines. Its chassis was an original feature. The Coventry
Ordnance biplane was a two-seater tractor built for the British Military
Trials. It had a 100 h.p. 14-cylinder Gnome engine, with propeller
geared down through a chain drive. The machine was an interesting
experiment, but not an unqualified success. The Moreau "Aerostable,"
fitted with a 50 h.p. Gnome, was a French attempt to obtain automatic
stability, but it only operated longitudinally. The pilot's nacelle was
pivoted under the main planes, wires were attached to the control
members so that the movements of the nacelle in its efforts to keep a
level keel brought them into operation. The Mersey monoplane, an entrant
for the British Military Trials, was designed to present a clear field
of view and fire. The 45 h.p. Isaacson engine was connected by a shaft
to a propeller mounted behind the nacelle on the top tail boom. It was a
promising experiment, but came to grief. The Radley-Moorhouse monoplane
was a sporting type machine on Bleriot lines, with 50 h.p. Gnome engine.
It was notable for its streamlined body and disc wheels.