Improvements in and relating to Aerial Machines.
Year: 1897

page_text: Improvements in and relating to Aerial Machines.
I, FREDERICK WILLIAM LANCHESTER, of Cobley Hill, Alvechurch, in the County
of Worcester, Engineer, do hereby declare the nature of this invention to be as
follows:-
?
My invention relates to improvements in machines for the purpose of aerial
locomotion and navigation, and refers more particularly to the construction of a
machine specifically heavier than the atmosphere that shall be able to traverse the air
in any desirable direction, either under the control of an aeronaut or otherwise.
Part of the present invention has for its object to provide means whereby both the
lateral and fore and aft stability of the machine is automatically secured; other
portions relate to the form and structure of the supporting surfaces and propellers,
and to the launching and controlling arrangements.
In constructing a machine in accordance with the present invention, I arrange a
body of elongated and preferably stream line form of suitable dimensions to contain
the propelling and other mechanism, and to provide sufficient accomodation for
whatever purpose required. I also provide two rigidly attached wings, one extending
horizontally on each side of the said body. These wings are constructed in the
manner hereinafter to be described, and are so arranged as to bear the whole or a
greater proportion of the weight of the machine by the reaction of the air in its
vicinity. Attached to the after extremity of the body, or to a prolongation thereof,
I arrange a horizontal plane which will be hereinafter referred to as the "tail plane'
and which may either consist of a thin plate of light wood or other material, or may
be built or framed up and covered with suitable material, and may be somewhat
curved or quite flat, according as it is arranged to support a portion of the load or
otherwise. From the centre line of the body, or from the aforesaid prolongation
thereof, I arrange fins projecting upwards. These fins may be constructed in the
same manner as the tail plane and are preferably arranged some distance apart and
so that their combined centre of pressure is somewhat aft of the centre of gravity
of the machine.
For the purpose of propulsion a motor of any known type may be employed to
drive a screw propeller or propellers after the manner of a steam vessel, but I prefer
to arrange a gas or oil motor (or a pair of such motors) of the type in which the
energy of each explosion is communicated to two oppositely rotating parts in order
to relieve the machine from unbalanced recoil, and prevent vibration. I prefer to
construct the propellers after the manner of cycle wheels, the rims being constructed
of flat strips of sufficient weight to act as flywheels for the motor, the blades of the
propellers being formed by means of fabric or thin plate stretched or otherwise fitted.
between suitably arranged pairs of spokes.
The form or wing employed to support the weight of the machine is preferably.
that of the soaring bird, that is to say of great lateral breadth and smali fore and aft
dimension, with a convex upper and a concave under surface, the intensity of the
curvature diminishing and the plan contour of the wing tapering towards its
extremity.

page_text: In one mode of constructing a wing in accordance with ne present invention, I
arrange a steel tube extending for about half the length of the wing, suitably trussed,
and carrying at its outer extremity a vertical cross pillar from the ends of which
wire stays are run out to all outstanding points of a skeleton structure which in its
turn attaches to the main tube. The steel tube and skeleton structure are included
between the upper and under surfaces of the wing which may be of silk or other
fabric, or thin sheet aluminium or other metal may be used. When fabric is
employed, it is preferable to arrange the fabric of the upper surface of closer texture
than that of the under, or a coat of varnish may be applied in order that it may bulge
properly when the machine is in motion.
The extremities of the wings may be capped by "planes" arranged normally to
the wing surfaces and conformably to the direction of flight, in order to minimise
the lateral dissipation of the supporting wave.
"
In order to control the course of the machine vertically, and also its velocity, suitable
gear is arranged to alter the angle made by the wings as a whole, and the tail plane,
relatively to one another, and also to vary the speed of the motor as desired. For each
angle of the tail plane relatively to the wings there is a corresponding" proper velocity
for the machine which it automatically seeks in the resulting alteration in its course
going downwards to increase its velocity, and upwards to diminish it, and though the
immediate effect of an alteration in the angle of the tail plane is to alter the course
of the machine, its ultimate effect is to alter the velocity. A permanent alteration
in the course can, however, be effected either upward or downward by respectively
increasing or decreasing the thrust of the propellers, which may be done by varying
the speed of the motor.
Instead of making an alteration in the angle of the tail plane, the same result
can be obtained by shifting the centre of gravity of the machine forward to increase
the "proper velocity," and backward to diminish it.
The lateral steering may be effected by means of a rudder as with a boat, or oue
of the fins may be used as a rudder and actuated by suitable mechanism, or an
alteration in the angle of the two wings relatively to one another or parts of them
will by giving a list sideways to the machine effect an alteration in its course.
In launching an aerial machine in accordance with the present invention, a slip is
arranged consisting of a pair of parallel wire ropes suitably stretched, on which the
machine runs either by its own weight and propulsion or by cable traction. The
machine is prevented from jumping the track by cord lashings, the latter being cut
away by fixed knives, as the machine leaves the slip.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
I, FREDERICK WILLIAM LANCHESTER, of Cobley Hill, Alvechurch, in the County of
Worcester, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained 4
in and by the following statement :-
My invention relates to improvements in machines for the purpose of aerial
locomotion and navigation and refers more particularly to the construction of a
machine specifically heavier than the atino-phere that shall be able to traverse the air
in any desirable direction, either under the control of an aëronaut or otherwise.

page_text: Part of the present invention has for its object to provide means whereby both the
lateral and fore and aft stability of the machine is automatically secured; other
portions relate to the form and structure of the supporting surfaces and propellers,
and to the launching and controlling arrangements.
In constructing a machine in accordance with the present invention, I arrange a
body of elongated and preferably stream line form of suitable dimensions to contain
the propelling and other mechanism-and to provide sufficient accommodation for
whatever purpose required.. I also provide two rigidly attached wings one extending
horizontally on each side of the said body. These wings are constructed in the
manner hereinafter to be described, and are so arranged as to bear the whole or a
greater proportion of the weight of the machine. by the reaction of the air in its
vicinity. Attached to the after extremity of the body or to a prolongation thereof; I
arrange a horizontal plane which will be hereinafter referred to as the "tail plaue"
and which may either consist of a thin plate of light wood or other material, or may
be built or framed up and covered with suitable material and may be somewhat
curved or quite flat, according as it is arranged to support a portion of the load or
otherwise. From the centre line of the body, or from the aforesaid prolongation
thereof, I arrange fins projecting upwards. These fins may be constructed in the
same manner as the tail plane and are preferable arranged some distance apart and so
that their combined centre of pressure is somewhat aft of the centre of gravity. of the
machine.
i
For the purpose of propulsion a motor of any known type may be employed to
drive a screw propeller or propellers, after the manner of a steam vessel, but I prefer
to arrange a gas or oil motor (or a pair of such motors) of the type in which the
energy of each explosion is communicated to two oppositely rotating parts in order.
to relieve the machine from unbalanced recoil, and prevent vibration. I prefer to
construct the propellers after the manner of cycle wheels, the rins being constructed
of Hat strips of sufficient weight to act as flywheels for the motor, the blades of the
propellers being formed by means of fabric or thin plate stretched or otherwise fitted
between suitably arranged pairs of spokes.
The form of wing employed to support the weight of the machine is preferably
that of the soaring bird, that is to say, of great lateral breadth and small, fore and
aft dimension with a convex upper and a concave under surface, the intensity of the
curvature diminishing and the plan contour of the wing tapering towards its
extremity.
In one mode of constructing a wing in accordance with the present invention, I
arrange a steel tube extending for about half the length of the wing, suitably trussed,
and carrying at its outer extremity a vertical cross pillar. from the ends of which
wire stays are run out to all outstanding points of a skeleton structure which in its
turu attaches to the main tube. The steel tube and skeleton structure are included
between the upper and under surfaces of the wing which may be of silk or other
fabric, or thin sheet aluminium or other metal may be used. When fabric is employed,
it is preferable to arrange the fabric of the upper surface of closer texture than that
of the under or a coat of varnish may be applied in order that it may bulge properly
when the machine is in motion.
The extremities of the wings may be capped by "planes" arranged normally to
the wing surfaces and conformably to the direction of flight, in order to minimise the
lateral dissipation of the supporting wave.
In order to control the course of the machine vertically, and also its velocity,
suitable gear is arranged to alter the angle made by the wings as a whole, and the
tail plane, relatively to one another, and also to vary the speed of the motor as desired.
For each angle of the tail plane relatively to the wings there is a corresponding
"natural velocity" for the machine which it automatically. seeks in the resulting
alteration in its course going downwards to increase its velocity, and upwards to
diminish it, and though the immediate effect of an alteration in the angle of the tail
plane is to alter the course of the machine, its ultimate effect is to alter the velocity.
"A permanent alteration in the course can, however, be effected either upwards' or

page_text: downward by respectively increasing or decreasing the thrust of the propellers which
may be done by varying the speed of the motor.
Instead of making an alteration in the angle of the tail plane, the same result can
be otained by shifting the centre of gravity of the machine forward to increase the
"natural velocity," and backward to diminish it.
The lateral steering may be effected by means of a rudder as with a boat or one of
the fins may be used as a rudder and actuated by suitable mechanism, or an alteration
in the angle of the two wings relatively to one another or parts of them will by
giving a list sideways to the machine effect an alteration in its course.
In launching an aerial machine in accordance with the present invention, a slip is
arranged consisting of a pair of parallel wire ropes suitable stretched, on which the
machine runs either by its own weight and propulsion or by cable traction. The
machine is prevented from jumping the track by cord lashings, the latter being cut
away by fixed knives, as the machine leaves the slip.
Referring to the accompanying sheets of illustrative drawings in which the same
alphabetical letters are used for like parts throughout, a, a, are the wings arranged
to support the whole or a greater portion of the weight of the machine; b is the
tail-plane, c, and d are the upwardly projecting fios; e, is the wing capping plane;
and f, and g are respectively the blades and rim of the novel form of fly-wheel
propeller that I preferably employ. The motor is denoted by the letter Z and the
cage" or car by the letter Y.
.6
Referring in detail to Sheet (1).-Figures 1, 2, and 3, represent respectively a side
and end elevation and plan of an aerial torpedo constructed in accordance with the
present invention, the propelling mechanism, Z, f, g, is shown somewhat
diagramatically and may be dispensed with altogether when only a moderate range
is required. In machines of moderate dimensions the wings a, a, may be cut from a
single piece of pine or other light wood and the plan form is preferably elliptical or
thereabouts as shown in Figure 3 and of gradually changing sectional form towards
the extremities, a series of suitable sections being shown in Figure 6 in which the
mean surface of curvature of the central section is shown as a dotted line throughout;
I find it advantageous thus to diminish the steepness of curvature towards the wing
extremities also to so arrange that the front edge "dips" considerably relatively to
the direction of motion which in Figure 6 is presumed to be across the paper from
right to left. Figures 4 and 5, show a modified form of wing truncated and provided
with the capping plane e, the function of these being to minimise the loss of energy
due to air circulation round the wind extremities. The proportion of major to minor
axis I find most desirable in the elliptical form of wing is from 10; I to 13; 1, a
greater ratio would be theoretically preferable but practical considerations have to be
taken into account. A single fin (shown dotted Figure 1) c, of sufficient length may
be substituted for the two separate fins c and d.
Figures 7, 8, and 9, show in end and side elevation and in detail, portions of a
launching apparatus constructed in accordance with the portion of my present
invention relating thereto. In the act of launching the machine is arranged to run
on tight wires or cords, being tethered thereto by lashings as shown in Figure 9 the
machine has its initial velocity imparted to it by any suitable mechanism such as a
cable actuated by a winding engine, or in some cases a catapult may be used in which
stretched caoutchouc is employed to store up the energy required. The wires at
their extremities pass over two end frames and are secured beyond in any suitable
manner, on the front frame (Figure 7) are carried two cutter blades i, i, of the form
indicated and are so arranged as to cut the lashings as the machine leaves its cradle.
Referring to Sheet 2.-Figures 10, 11, and 12, illustrate a machine designed for
the purposes of aerial navigation and in this arrangement a tubular rectangular
framework, ¹, is built up, the side k, k, forms the "back-bone" of the wing
structure and is extended to m, m, the right and left hand wings are shown in the
figure of alternative design, the left hand wing is shown of truncated form and fitted
with a capping plane, the right hand wing is shown of tapering form and is built up
of a framework covered with a suitable fabric to give a configuration as closely as

page_text: possible resembling that indicated by Figure 6 already referred to. At the point m, a
vertical strut is inserted forming at its extremities points of attachment for a number
of wire stays connecting up to all outstanding portions of the wing framework,
Figure 11. The rear portion of the main framework 1, 1, may conveniently be made
to form part of the structure of the tail plane as shown in Figure 12, one method of
framing up the wings, tail plane, and fins is illustrated in Figure 17, in which the
detail of a fin is shown on a larger scale and will be hereinafter referred to at greater
length.
I preferably use a motor of my two crank balanced type, this is figured ZZ,
in Figures 10, 11, 12, and is carried off brackets attached to the two side tubes of the
main framework, the two propellers the construction of which will be further
described are right and left hand to correspond with the reversed rotation of the two
shafts. The motor itself is as far as possible enclosed in a casing of stream-line form,
but the cylinders are preferably exposed to the cooling action of the air in the case of
motors of the internal combustion type.
22
Accommodation for the aeronaut and any accessories to the use of the machine is
provided in the "cage or car-body Y which is arranged well forward so as to bring
the centre of gravity of the machine sufficiently near to the centre of pressure of the
supporting surfaces; the actual construction of the car body adınits of considerable
latitude; woodwork, basket-work, or other suitable material inay be employed but as
far as practicable a stream-line form should be adopted.
Provision is shown for steering and for altering the natural velocity of the machine;
the steering mechanism is arranged to actuate the two rearmost fins (Figures 13,
and 14) these are coupled together by a link u and are operated upon by a bell
crank lever w and actuating link the latter connecting to suitable operating
mechanism in the car. The gear shown for effecting an alteration in the natural
velocity of the machine consists of a cross struts attached to the tail plane and a
tension cord t, t, t, fastened to the structure of the tail plane and carried forward to
the bobbin and thence actuated by gear within the car, the tail plane in this
arrangement being allowed a certain amount of angular movement about its points of
attachment. If desired however steering or the alteration of the natural velocity may
be done either wholly or in part by shifting ballast, or by the movement of
the aeronaut himself, the centre of gravity of the machine being thrown laterally in
the direction in which it is desired to steer or by moving forward to increase or back-
ward to diminish the natural velocity.
Referring to Sheet 3.-Figures 15 and 16, show in section and elevation one mode
of constructing a combined fly-wheel and screw propeller in accordance with
the present invention. The rim is preferably made of wood and is securely spoked
and built on to a cast boss as shown, tangent spokes are arranged to render the wheel
sufficiently rigid to act as a fly-wheel and further spokes are fitted at suitable intervals
to which fabric "sails" are laced or otherwise attached to form the vanes f, f, f, but
these vanes may be formed by carving out of wood or other material if desired.
tapering extremity may be given to the propeller boss by fitting to it a tent like
structure as depicted in the figure.
A
The rim is able in certain cases to either supplement or even supplant the tail-
plane and rear fin by virtue of the great resistance it offers to lateral motion in any
direction; for instance in Figures 1, 2, and 3, (Sheet 1) when a propeller, such as that
shown, is employed the fin d and tail-plane b could be dispensed with, though
it might be found advantageous to somewhat increase the width of the rim g in that
A further advantage possessed by my new propeller is that the flat form of rim
acts to a certain extent to increase the efficiency of the blades bearing the same rela-
tion to them that the capping planes do to the supporting wings.
case.
When a single propeller is employed as in Figures 1, 2 and 3, a small weight may
be arranged to balance the turning moment due to the reaction of the propeller and
mechanism.
Figures 17 and 18 to which reference has already been made illustrate a method of
construction for the fin framework, also applicable to the tail-plane and wings;

page_text: the drawing represents one of the fins divested of its external covering, a
tubular socket o is built on to the framework of the machine and carries a wooden
blade p which is capped by a sheet metal socket q, this cap carries studs in its lower
corners over which pass the wire stays r, r, and r, r, tightened by nipples fitted to one
of the main tubes in the manner shown.
It may be briefly stated that in a machine constructed as herein described the tail-
plane acting in conjunction with the supporting wings has for its principal functions
the preservation of longitudinal equilibrium and the regulation of speed,. whilst the
fins are concerned with the maintenance of transverse equilibrium and control of
geographic direction, the inclination of the course to the horizontal is under the
control of the propeller thrust.
The behaviour of the machine under different conditions and the function of its
various parts will be better understood from the following explanatory descrip-
tion.
When a machine constructed as herein before described travels through the air
with a sufficient velocity its weight is supported dynamically by the reaction of the
air on the upper and under wing surfaces, the curved form of section developing a
region of pressure beneath and rarefaction above in the same manner as a simple
inclined plane but with the advantage of greatly reduced resistance in the line of
motion. Now if the velocity of travel is insufficient the air reaction will be deficient
and if the velocity be excessive the air reaction becomes greater than the weight of
the machine and consequently there is for any particular adjustment of a machine a
certain speed at which its weight will just be buoyed up so that (so long as this
critical speed be maintained) its centre of gravity will continue to move in a straight
line, that is to say that at this speed (which has already been referred to as the
"natural velocity") there is no tendency of the course of the machine to change.
Now let us suppose that a machine without motor be launched horizontally at its
"natural velocity" then at first no change in its direction of motion takes place, but
as its velocity falls owing to the resistance of the air (frictional and otherwise) it
gradually assumes a course inclined downwards and after some oscillation finally
settles down to such an inclination as will by its descent enable it to be supplied with
the energy necessary for its propulsion, the steepness of the descent under given
conditions depends upon the rate of dissipation of energy by the resistance of the
machine this angle may be termed the angle of "recuperation." If now we suppose
the machine to be launched at a speed considerably above its natural velocity, then
in the first instance it takes an upward course. of gradually increasing inclination
till its excess of kinetic energy has been absorbed as potential, the inclination of its
course then gradually diminishes till it again becomes horizontal, when, its velocity
having become considerably deficient its course takes a downward trend and thus it
proceeds to describe curves in the air of approximately trochoidal form of gradually
diminishing amplitude slowly settling down to its angle of "recuperation." If the
launching velocity be excessive (greater than 1 times the natural velocity in most
cases) the machine runs a serious risk of being capsized and the limit of longitudinal
stability may be said to be reached somewhere about this point.
The natural velocity of a machine may be modified at will by altering the relative
angle between the wings and tail-plane, thus causing the former to meet the air at a
greater or less angle.
The power of controlling the natural velocity as well as the launching velocity will
in many cases permit of an aerial torpedo being successfully directed from behind a
rampart or otherwise at a hidden object.
If in the course of its evolutions a machine (constructed as herein before described)
heel over side ways one way or the other or if a "rolling" motion be set up, the first
effect is for the machine to begin to slide down, so to speak, in the direction in which
it is for the time being inclined, this motion is very quickly arrested however by the
resistance of the "fins." whose centre of pressure. is arranged above the centre of
gravity of the machine and equilibrium is thereby restored, a similar result might be
brought about by inclining the wings or the tips of the wings upwards to the right

page_text: and left but an arrangement of fins is specially valuable owing to its "
action on any side oscillations that may be set up.
damping'
"
It is easy to understand when a motor is employed for the purposes of propulsion
that according to the magnitude of the thrust transmitted to the machine the "angle
of recuperation" is diminished and if the thrust be sufficient the machine will retain
its natural velocity with a horizontal course or even an upwardly inclined course
and it will moreover automatically adapt itself to whatever thrust may be applied so
that the effect of an increased thrust is only to increase the velocity of the machine
in quite a transitory manner the final result, after the trochoidal oscillations due
to the disturbance have settled down, being a change in the course of the machine
in an upward direction.
Thus in order to effect a change in the course of the machine in a vertical plane I
operate on the propelling mechanism by either increasing or diminishing the supply
of working fluid or by such other means as may be appropriate to the motor employed.
I may in certain cases introduce a counter thrust, instead of operating on the motor
mechanisin by erecting a small plane or other obstruction perpendicular to the
direction of the motion of the machine so as to cause it to take a downward course.
When only a temporary change of direction is required as when evading an obstacle
the tail plane may be used with effect for vertical steering but only within the limits
of the safe velocity of the machine.
"
The surfaces of the limbs (ie. wings, tail-plane, and fins) of a machine, constructed
as hereinbefore described, by acting on the air both support the weight of the machine
and secure it stability and by their function these surfaces may be divided into
supporting" surfaces and "dirigent" surfaces and the limbs may be termed
"supporting" and "dirigent" limbs accordingly. In the arrangements illustrated
in the accompanying drawings the wings are the main supporting limbs the fins and
tail-plane are dirigent only, the latter may however act as a subsidiary supporting
limb in which case the centre of gravity is arranged somewhat aft of the wing area
and the tail-plane is preferably made of a curved section in order to carry out its
additional function with the least resistance possible, in order however not to infringe
the necessary conditions of stability the pressure intensity on the tail-plane should be
made less than that on the wing area.
Having now particularly described and ascertained the nature of iny said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In aerial machines the method of securing stability by means of a supporting
surface or surfaces and dirigent surfaces substantially as herein before set forth.
2. In aerial machines whose weight is sustained by the dynamic reaction of the
air on supporting surfaces the combination of dirigent surfaces arranged and operating
substantially as hereinbefore set forth with reference to Figures 1, 2, 3, and 10, 11, 12,
of the accompanying drawings.
3. In aerial machines the method of permanently altering or "laying" the course
of the machine in a vertical direction by increasing or decreasing the propeller thrust
or by introducing a counter thrust substantially as herein before set forth.
4. In aerial machines the method of varying the velocity of travel by the adjust-
ment of the wings or main supporting limbs and the tail-plane relatively to one
another or by the alteration of the position of the centre of gravity of the machine
substantially as herein before set forth.
5. An aerial torpedo or air borne projectile substantially as described with reference
to Figures 1, 2, 3, 4, and 5, of the accompanying drawings.
6. An aerial machine comprising a tubular foursided main frame with supporting
and dirigent limbs and propelling mechanism arranged and operating substantially
as hereinbefore described with reference to Figures 10, 11, 12, of the accompanying
drawings.
7. A combined fly-wheel and propeller constructed and operating substantially as

page_text: herein before set forth with reference to Figures 1, 2, 3, and 15, and 16, of the
accompanying drawings.
8. In aerial machines whose weight is sustained by the dynamic reaction of the
air on supporting surfaces the arrangement of capping plane as and for the purpose
hereinbefore set forth.
9. The method of launching aerial machines from a wire track in which suitable
knives are arranged to cut the machine clear at the moment of discharge, as set
forth.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.