The Farman biplane, showing the position of the hinged ailerons when at rest. At full speed these surfaces stream out in the wind in line with the planes to which they are attached.
Diagram of the Farman biplane. A later type has the hinged ailerons also on the tail planes.
The motor has 4 cylinders, and turns a propeller made of wood, 8 feet 6 inches in diameter, at a speed of 1,300 revolutions per minute—nearly three times as fast as the speed of the Wright propellers, which are about the same size. The propeller is placed just under the rear edge of the upper main plane, the lower one being cut away to make room for the revolving blades. The motor develops 45 to 50 horse-power, and drives the machine at a speed of 41 miles per hour.
The “racing Farman” is slightly different, having the hinged ailerons only on one of the main planes. The reason for this is obvious. Every depression of the ailerons acts as a drag on the air flowing under the planes, increasing the lift at the expense of the speed.
Sketch of Farman machine, showing position of operator. A, A, main planes; B, elevator; C, motor; P, tail planes.
The whole structure is mounted upon skids with wheels attached by a flexible connection. In case of a severe jar, the wheels are pushed up against the springs until the skids come into play.
The elevator and the wing naps are controlled by a lever at the right hand of the pilot. This lever moves on a universal joint, the side-to-side movement working the flaps, and the forward-and-back motion the elevator. Steering to right or left is done with a bar operated by the feet.
Henri Farman carrying a passenger across country.
Farman has himself made many records with his machine, and so have others. With a slightly larger and heavier machine than the one described, Farman carried two passengers a distance of 35 miles in one hour.
THE CURTISS BIPLANE.
This American rival of the Wright biplane is the lightest machine of this type so far constructed. The main planes are but 29 feet in spread, and 4 feet 6 inches in width, and are set not quite 5 feet apart. The combined area of the two planes is 250 square feet. The main planes are placed midway of the length of the fore-and-aft structure, which is nearly 30 feet. At the forward end is placed the elevator, and at the rear end is the tail—one small plane surface—and the vertical rudder surface in two parts, one above and the other below the tail plane. Equilibrium is controlled by changing the slant of two small balancing planes which are placed midway between the main planes at the outer ends, and in line with the front edges. These balancing planes are moved by a lever standing upright behind the pilot, having two arms at its upper end which turn forward so as to embrace his shoulders. The lever is moved to right or to left by the swaying of the pilot’s body.
Glenn H. Curtiss in his machine ready to start. The fork of the balancing lever is plainly seen at his shoulders. Behind him is the radiator, with the engine still further back.
The motor is raised to a position where the shaft of the propeller is midway between the levels of the main planes, and within the line of the rear edges, so that they have to be cut away to allow the passing of the blades. The motor is of the V type, with 8 cylinders. It is 30 horse-power and makes 1,200 revolutions per minute. The propeller is of steel, two-bladed, 6 feet in diameter, and revolves at the same speed as the shaft on which it is mounted. The high position of the engine permits a low running gear. There are two wheels under the rear edges of the main planes, and another is placed half-way between the main planes and the forward rudder, or elevator. A brake, operated by the pilot’s foot, acts upon this forward wheel to check the speed at the moment of landing.
Another type of Curtiss machine has the ailerons set in the rear of the main planes, instead of between them.
The Curtiss is the fastest of the biplanes, being excelled in speed only by some of the monoplanes. It has a record of 51 miles per hour.
THE CODY BIPLANE.
The Cody biplane has the distinction of being the first successful British aeroplane. It was designed and flown by Captain S. F. Cody, at one time an American, but for some years an officer in the British army.
It is the largest and heaviest of all the biplanes, weighing about 1,800 lbs., more than three times the weight of the Curtiss machine. Its main planes are 52 feet in lateral spread, and 7 feet 6 inches in width, and are set 9 feet apart. The combined area of these sustaining surfaces is 770 square feet. The upper plane is arched, so that the ends of the main planes are slightly closer together than at the centre.
The elevator is in two parts placed end to end, about 12 feet in front of the main planes. They have a combined area of 150 square feet. Between them and above them is a small rudder for steering to right or left in conjunction with the large rudder at the rear of the machine. The latter has an area of 40 square feet.
There are two small balancing planes, set one at each end of the main planes, their centres on the rear corner struts, so that they project beyond the tips of the planes and behind their rear lines.
The Cody biplane in flight. Captain Cody has both hands raised above his head, showing the automatic stability of his machine.
The biplane is controlled by a lever rod having a wheel at the end. Turning the wheel moves the rudders; pushing or pulling the wheel works the elevator; moving the wheel from side to side moves the balancing planes.
There are two propellers, set one on each side of the engine, and well forward between the main planes. They are of wood, of the two-bladed type, 7 feet in diameter. They are geared down to make 600 revolutions per minute. The motor has 8 cylinders and develops 80 horse-power at 1,200 revolutions per minute.
The machine is mounted on a wheeled running gear, two wheels under the front edge of the main planes and one a short distance forward in the centre. There is also a small wheel at each extreme end of the lower main plane.
The Cody biplane has frequently carried a passenger, besides the pilot, and is credited with a speed of 38 miles per hour.
The first aeroplane flights ever made in England were by Captain Cody on this biplane, January 2, 1909.
THE SOMMER BIPLANE.
The Sommer biplane is closely similar to the Farman machine, but has the hinged ailerons only on the upper plane. Another difference is that the tail has but one surface, and the rudder is hung beneath it. Its dimensions are:—Spread of main planes, 34 feet; depth (fore-and-aft), 6 feet 8 inches; they are set 6 feet apart. The area of the main planes is 456 square feet; area of tail, 67 square feet; area of rudder, 9 square feet. It is driven by a 50-horsepower Gnome motor, turning an 8-foot, two-bladed propeller.
M. Sommer has flown with three passengers, a total weight of 536 lbs., besides the weight of the machine.
THE BALDWIN BIPLANE.
The Baldwin biplane, designed by Captain Thomas S. Baldwin, the distinguished balloonist, resembles the Farman type in some features, and the Curtiss in others. It has the Curtiss type of ailerons, set between the wings, but extending beyond them laterally. The elevator is a single surface placed in front of the machine, and the tail is of the biplane type with the rudder between. The spread of the main planes is 31 feet 3 inches, and their depth 4 feet 6 inches. A balancing plane of 9 square feet is set upright (like a fin) above the upper main plane, on a swivel. This is worked by a fork fitting on the shoulders of the pilot, and is designed to restore equilibrium by its swinging into head-resistance on one side or the other as may be necessary.
The Baldwin biplane, showing balancing plane above upper main plane.
The motive power is a 4-cylinder Curtiss motor, which turns a propeller 7 feet 6 inches in diameter, set just within the rear line of the main planes, which are cut away to clear the propeller blades.
THE BADDECK BIPLANE.
The newest biplane of the Aerial Experiment Association follows in general contour its successful precursor, the “Silver Dart,” with which J. A. D. McCurdy made many records. The “Baddeck No. 2” is of the biplane type, and both the planes are arched toward each other. They have a spread of 40 feet, and are 7 feet in depth at the centre, rounding to 5 feet at the ends, where the wing tips, 5 feet by 5 feet, are hinged. The elevator is also of the biplane type, two surfaces each 12 feet long and 28 inches wide, set 30 inches apart. This is mounted 15 feet in front of the main planes. The tail is mounted 11 feet in the rear of the main planes, and is the same size and of the same form as the elevator.
The controls are operated by the same devices as in the Curtiss machine. The propeller is 7 feet 8 inches in diameter, and is turned by a six-cylinder automobile engine of 40 horse-power running at 1,400 revolutions per minute. The propeller is geared down to run at 850 revolutions per minute. The motor is placed low down on the lower plane, but the propeller shaft is raised to a position as nearly as possible that of the centre of resistance of the machine. The speed attained is 40 miles per hour.
The McCurdy biplane, “Baddeck No. 2.”
A unique feature of the mechanism is the radiator, which is built of 30 flattened tubes 7 feet 6 inches long, and 3 inches wide, and very thin. They are curved from front to rear like the main planes, and give sufficient lift to sustain their own weight and that of the water carried for cooling the cylinders. The running gear is of three wheels placed as in the Curtiss machine. The “Baddeck No. 2” has made many satisfactory flights with one passenger besides the pilot.
THE HERRING BIPLANE.
At the Boston Aircraft Exhibition in February, 1910, the Herring biplane attracted much attention, not only because of its superiority of mechanical finish, but also on account of its six triangular stabilizing fins set upright on the upper plane. Subsequent trials proved that this machine was quite out of the ordinary in action. It rose into the air after a run of but 85 feet, and at a speed of only 22 miles per hour, and made a 40-degree turn at a tipping angle of 20 degrees. As measured by the inventor, the machine rose in the air with the pilot (weighing 190 lbs.), with a thrust of 140 lbs., and required only a thrust of from 80 to 85 lbs. to keep it flying.
The spread of the planes is 28 feet, and they are 4 feet in depth, with a total supporting surface of 220 feet. A 25 horse-power Curtiss motor turns a 4-bladed propeller of 6 feet diameter and 5-foot pitch (designed by Mr. Herring) at the rate of 1,200 revolutions per minute.
The L. A. W. (League of American Wheelmen) biplane at the Boston Aircraft Exhibition, February, 1910. Note the peculiar curve of the divided planes. The motor is of the rotating type, of 50 horse-power.
The elevator consists of a pair of parallel surfaces set upon hollow poles 12 feet in front of the main planes. The tail is a single surface.
The stabilizing fins act in this manner: when the machine tips to one side, it has a tendency to slide down an incline of air toward the ground. The fins offer resistance to this sliding, retarding the upper plane, while the lower plane slides on and swings as a pendulum into equilibrium again.
THE BREGUET BIPLANE.
The Breguet biplane is conspicuous in having a biplane tail of so large an area as to merit for the machine the title “tandem biplane.” The main planes have a spread of 41 feet 8 inches, and an area of 500 square feet. The tail spreads 24 feet, and its area is about 280 square feet. The propeller is three-bladed, 8 feet in diameter, and revolves at a speed of 1,200 revolutions per minute. It is placed in front of the main plane, after the fashion of the monoplanes. The motive power is an 8-cylinder R-E-P engine, developing 55 horse-power.
Courtesy of N. Y. Sun.
The Seddon tandem biplane, constructed by Lieutenant Seddon of the British Navy. The area of its planes is 2,000 square feet. Compare its size with that of the monoplane in the background. It is intended to carry ten persons.
Wright biplane. Curtiss biplane.
Comparative build and area of prominent American biplanes.
Voisin biplane. Breguet biplane.
Comparative build and area of prominent European biplanes.
Chapter VI.
FLYING MACHINES: THE MONOPLANE.
The common goal—Interchanging features—The Bleriot machine—First independent flyer—Construction and controls—The “Antoinette”—Large area—Great stability—Santos-Dumont’s monoplane—Diminutive size—R-E-P monoplane—encased structure—Hanriot machine—Boat body—Sturdy build—Pfitzner machine—Lateral type—Thrusting propeller—Fairchild, Burlingame, Cromley, Chauviere, Vendome, and Moisant monoplanes.
In all the ardent striving of the aviators to beat each other’s records, a surprisingly small amount of personal rivalry has been developed. Doubtless this is partly because their efforts to perform definite feats have been absorbing; but it must also be that these men, who know that they face a possible fall in every flight they make, realize that their competitors are as brave as themselves in the face of the same danger; and that they are actually accomplishing marvellous wonders even if they do no more than just escape disastrous failure. Certain it is that each, realizing the tremendous difficulties all must overcome, respects the others’ ability and attainments.
Consequently we do not find among them two distinctly divergent schools of adherents, one composed of the biplanists, the other of the monoplanists. Nor are the two types of machines separated in this book for any other purpose than to secure a clearer understanding of what is being achieved by all types in the progress toward the one common goal—the flight of man.
The distinctive feature of the monoplane is that it has but one main plane, or spread of surface, as contrasted with the two planes, one above the other, of the biplane. Besides the main plane, it has a secondary plane in the rear, called the tail. The office of this tail is primarily to secure longitudinal, or fore-and-aft, balance; but the secondary plane has been so constructed that it is movable on a horizontal axis, and is used to steer the machine upward or downward. While most of the biplanes now have a horizontal tail-plane, they were not at first so provided, but carried the secondary plane (or planes) in front of the main planes. Even in the latest type brought out by the conservative Wright brothers, the former large-surfaced elevator in front has been removed, and a much smaller tail-plane has been added in the rear, performing the same function of steering the machine up or down, but also providing the fore-and-aft stabilizing feature formerly peculiar to the monoplane. Another feature heretofore distinctively belonging to the monoplane has been adopted by some of the newer biplanes, that of the traction propeller—pulling the machine behind it through the air, instead of pushing it along by a thrusting propeller placed behind the main planes.
The continual multiplication of new forms of the monoplane makes it possible to notice only those which exhibit the wider differences.
THE BLERIOT MONOPLANE.
The Bleriot monoplane has the distinction of being the first wholly successful flying machine. Although the Wright machine was making flights years before the Bleriot had been built, it was still dependent upon a starting device to enable it to leave the ground. That is, the Wright machine was not complete in itself, and was entirely helpless at even a short distance from its starting tower, rail, and car, which it was unable to carry along. Because of its completeness, M. Bleriot was able to drive his machine from Toury to Artenay, France (a distance of 8¾ miles) on October 31, 1908, make a landing, start on the return trip, make a second landing, and again continue his journey back to Toury, all under his own unassisted power. This feat was impossible to the Wright machine as it was then constructed, thus leaving the Bleriot monoplane in undisputed pre-eminence in the history of aviation.
A Bleriot monoplane, “No. XI,” in flight.
At a little distance, where the details of construction are not visible, the Bleriot machine has the appearance of a gigantic bird. The sustaining surface, consisting of a single plane, is divided into two wings made of a stiff parchment-like material, mounted one on each side of a framework of the body, which is built of mahogany and whitewood trussed with diagonal ties of steel wire.
The main plane has a lateral spread of 28 feet and a depth of 6 feet, and is rounded at the ends. It has an area of about 150 square feet, and is slightly concave on the under side. The tail-plane is 6 feet long and 2 feet 8 inches in depth; at its ends are the elevators, consisting of pivoted wing tips each about 2 feet 6 inches square with rounded extremities. The rudder for steering to left or right is mounted at the extreme rear end of the body, and has an area of 9 square feet.
The Bleriot “No. XII.,” showing new form of tail, and the complete encasing with fabric.
The body is framed nearly square in front and tapers to a wedge-like edge at the rear. It extends far enough in front of the main plane to give room for the motor and propeller. The seat for the pilot is on a line with the rear edge of the main plane, and above it. The forward part of the body is enclosed with fabric.
Forward chassis of Bleriot monoplane, showing caster mounting of wheels. The framing of the body is shown by the dotted lines.
The machine is mounted on three wheels attached to the body: two at the front, with a powerful spring suspension and pivoted like a caster, and the other rigidly at a point just forward of the rudders.
The lateral balance is restored by warping the tips of the main plane; if necessary, the elevator tips at the rear may be operated to assist in this. All the controls are actuated by a single lever and a drum to which the several wires are attached.
Diagram of Bleriot “No. XI.,” from the rear. A, A, main plane; B, tail; C, body; D, D, wing tips of tail; E, rudder; H, propeller; M, motor; O, axis of wing tips; R, radiator; a, a, b, b, spars of wings; h, h, guy wires; p, k, truss.
The motors used on the Bleriot machines have varied in type and power. In the “No. XI.,” with which M. Bleriot crossed the English Channel, the motor was a 3-cylinder Anzani engine, developing 24 horse-power at 1,200 revolutions per minute. The propeller was of wood, 2-bladed, and 6 feet 9 inches in diameter. It was mounted directly on the shaft, and revolved at the same speed, giving the machine a velocity of 37 miles per hour. This model has also been fitted with a 30 horse-power R-E-P (R. Esnault-Pelterie) motor, having 7 cylinders. The heavier type “No. XII.” has been fitted with the 50 horse-power Antoinette 8-cylinder engine, or the 7-cylinder rotating Gnome engine, also of 50 horse-power.
Sketches showing relative size, construction, and position of pilot in the Bleriot machines; “No. XI.” (the upper), and “No. XII.” (the lower).
The total weight of the “No. XI.” monoplane is 462 pounds, without the pilot.
THE ANTOINETTE MONOPLANE.
The Antoinette is the largest and heaviest of the monoplanes. It was designed by M. Levavasseur, and has proved to be one of the most remarkable of the aeroplanes by its performances under adverse conditions; notably, the flight of Hubert Latham in a gale of 40 miles per hour at Blackpool in October, 1909.
The Antoinette has a spread of 46 feet, the surface being disposed in two wings set at a dihedral angle; that is, the outer ends of the wings incline upward from their level at the body, so that at the front they present the appearance of a very wide open “V.” These wings are trapezoidal in form, with the wider base attached to the body, where they are 10 feet in depth (fore and aft). They are 7 feet in depth at the tips, and have a total combined area of 377 square feet. The great depth of the wings requires that they be made proportionally thick to be strong enough to hold their form. Two trussed spars are used in each wing, with a short mast on each, half-way to the tip, reaching below the wing as well as above it. To these are fastened guy wires, making each wing an independent truss. A mast on the body gives attachment for guys which bind the whole into a light and rigid construction. The framework of the wings is covered on both sides with varnished fabric.
The Antoinette monoplane in flight.
The body is of triangular section. It is a long girder; at the front, in the form of a pyramid, expanding to a prism at the wings, and tapering toward the tail. It is completely covered with the fabric, which is given several coats of varnish to secure the minimum of skin friction.
Diagram showing construction of the Antoinette monoplane.
The tail is 13 feet long and 9 feet wide, in the form of a diamond-shaped kite. The rear part of it is hinged to be operated as the elevator. There is a vertical stabilizing fin set at right angles to the rigid part of the tail. The rudder for steering to right or left is in two triangular sections, one above and the other below the tail-plane. The entire length of the machine is 40 feet, and its weight is 1,045 pounds.
It is fitted with a motor of the “V” type, having 8 cylinders, and turning a 2-bladed steel propeller 1,100 revolutions per minute, developing from 50 to 55 horse-power.
The control of the lateral balance is by ailerons attached to the rear edges of the wings at their outer ends. These are hinged, and may be raised as well as lowered as occasion demands, working in opposite directions, and thus doubling the effect of similar ailerons on the Farman machine, which can only be pulled downward.
The machine is mounted on two wheels under the centre of the main plane, with a flexible wood skid projecting forward. Another skid is set under the tail.
It is claimed for the Antoinette machine that its inherent stability makes it one of the easiest of all for the beginner in aviation. With as few as five lessons many pupils have become qualified pilots, even winning prizes against competitors of much wider experience.
Diagrams showing comparative size and position of surfaces and structure of the Bleriot (left) and Antoinette (right) monoplanes.
THE SANTOS-DUMONT MONOPLANE.
This little machine may be called the “runabout” of the aeroplanes. It has a spread of only 18 feet, and is but 20 feet in total length. Its weight is about 245 pounds.
The main plane is divided into two wings, which are set at the body at a dihedral angle, but curve downward toward the tips, forming an arch. The depth of the wings at the tips is 6 feet. For a space on each side of the centre they are cut away to 5 feet in depth, to allow the propeller to be set within their forward edge. The total area of the main plane is 110 square feet.
The tail-plane is composed of a vertical surface and a horizontal surface intersecting. It is arranged so that it may be tilted up or down to serve as an elevator, or from side to side as a rudder. Its horizontal surface has an area of about 12 square feet.
The engine is placed above the main plane and the pilot’s seat below it. The body is triangular in section, with the apex uppermost, composed of three strong bamboo poles with cross-pieces held in place by aluminum sockets, and cross braced with piano wire.
Santos-Dumont’s La Demoiselle in flight.
The motor is of the opposed type, made by Darracq, weighing only 66 pounds, and developing 30 horse-power at 1,500 revolutions per minute. The propeller is of wood, 2-bladed, and being mounted directly on the shaft of the motor, revolves at the same velocity. The speed of the Santos-Dumont machine is 37 miles per hour.
The Darracq motor and propeller of the Santos-Dumont machine. The conical tank in the rear of the pilot’s seat holds the gasoline.
The lateral balance is preserved by a lever which extends upward and enters a long pocket sewed on the back of the pilot’s coat. His leaning from side to side warps the rear edges of the wings at their tips. The elevator is moved by a lever, and the rudder by turning a wheel.
While this machine has not made any extended flights, Santos-Dumont has travelled in the aggregate upward of 2,000 miles in one or another of this type.
The plans, with full permission to any one to build from them, he gave to the public as his contribution to the advancement of aviation. Several manufacturers are supplying them at a cost much below that of an automobile.
Sketch showing position of pilot in Santos-Dumont machine. A, main plane; B, tail plane; C, motor.
THE R-E-P MONOPLANE.
The Robert Esnault-Pelterie (abbreviated by its inventor to R-E-P) monoplane, viewed from above, bears a striking resemblance to a bird with a fan-shaped tail. It is much shorter in proportion to its spread than any other monoplane, and the body being entirely covered with fabric, it has quite a distinct appearance.
The plane is divided into two wings, in form very much like the wings of the Antoinette machine. Their spread, however, is but 35 feet. Their depth at the body is 8 feet 6 inches, and at the tips, 5 feet. Their total combined area is 226 square feet.
The body of the R-E-P machine has much the appearance of a boat, being wide at the top and coming to a sharp keel below. The boat-like prow in front adds to this resemblance. As the body is encased in fabric, these surfaces aid in maintaining vertical stability.
A large stabilizing fin extends from the pilot’s seat to the tail. The tail is comparatively large, having an area of 64 square feet. Its rear edge may be raised or lowered to serve as an elevator. The rudder for steering to right or left is set below in the line of the body, as in a boat. It is peculiar in that it is of the “compensated” type; that is, pivoted near the middle of its length, instead of at the forward end.
The control of the lateral balance is through warping the wings. This is by means of a lever at the left hand of the pilot, with a motion from side to side. The same lever moved forward or backward controls the elevator. The steering lever is in front of the pilot’s seat, and moves to right or to left.
| Elevation, showing large stabilizing fin; boat-like body encased in fabric; and compensated rudder, pivoted at the rear end of the fin. | |
| Plan, showing comparative spread of surfaces, and the attachment of wheels at the wing tips. | |
Graphic sketch showing elevation and plan of the R-E-P monoplane. |
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The motor is an invention of M. Esnault-Pelterie, and may be of 5, 7, or 10 cylinders, according to the power desired. The cylinders are arranged in two ranks, one in the rear of the other, radiating outward from the shaft like spokes in a wheel. The propeller is of steel, 4-bladed, and revolves at 1,400 revolutions per minute, developing 35 horse-power, and drawing the machine through the air at a speed of 47 miles per hour.
THE HANRIOT MONOPLANE.
Among the more familiar machines which have been contesting for records at the various European meets during the season of 1910, the Hanriot monoplane earned notice for itself and its two pilots, one of them the fifteen-year-old son of the inventor. At Budapest the Hanriot machine carried off the honors of the occasion with a total of 106 points for “best performances,” as against 84 points for the Antoinette, and 77 points for the Farman biplane. A description of its unusual features will be of interest by way of comparison.
In general appearance it is a cross between the Bleriot and the Antoinette, the wings being shaped more like the latter, but rounded at the rear of the tips like the Bleriot. Its chief peculiarity is in the body of the machine, which is in form very similar to a racing shell—of course with alterations to suit the requirements of the aeroplane. Its forward part is of thin mahogany, fastened upon ash ribs, with a steel plate covering the prow. The rear part of the machine is covered simply with fabric.
The spread of the plane is 24 feet 7 inches, and it has an area of 170 square feet. The length of the machine, fore-and-aft, is 23 feet. Its weight is 463 pounds. It is mounted on a chassis having both wheels and skids, somewhat like that of the Farman running gear, but with two wheels instead of four.
The Hanriot machine is sturdily built all the way through, and has endured without damage some serious falls and collisions which would have wrecked another machine.
It is fitted either with a Darracq or a Clerget motor, and speeds at about 44 miles per hour.
THE PFITZNER MONOPLANE.
The Pfitzner monoplane has the distinction of being the first American machine of the single-plane type. It was designed and flown by the late Lieut. A. L. Pfitzner, and, though meeting with many mishaps, has proved itself worthy of notice by its performances, through making use of an entirely new device for lateral stability. This is the sliding wing tip, by which the wing that tends to fall from its proper level may be lengthened by 15 inches, the other wing being shortened as much at the same time.
There is no longitudinal structure, as in the other monoplanes, the construction being transverse and built upon four masts set in the form of a square, 6 feet apart, about the centre. These are braced by diagonal struts, and tied with wires on the edges of the squares. They also support the guys reaching out to the tips of the wings.
The Pfitzner monoplane from the rear, showing the sliding wing tips; dihedral angle of the wings; square body; and transverse trussed construction.
The plane proper is 31 feet in spread, to which the wing tips add 2½ feet, and is 6 feet deep, giving a total area of 200 square feet. A light framework extending 10 feet in the rear carries a tail-plane 6 feet in spread and 2 feet in depth. Both the elevator and the rudder planes are carried on a similar framework, 14 feet in front of the main plane.
The Pfitzner monoplane, showing the structure of the body; the two conical gasoline tanks above; the propeller in the rear. Lieutenant Pfitzner at the wheel.
The wings of the main plane incline upward from the centre toward the tips, and are trussed by vertical struts and diagonal ties.
The motor is placed in the rear of the plane, instead of in front, as in all other monoplanes. It is a 4-cylinder Curtiss motor, turning a 6-foot propeller at 1,200 revolutions per minute, and developing 25 horse-power.
The Pfitzner machine has proved very speedy, and has made some remarkably sharp turns on an even keel.
OTHER MONOPLANES.
Several machines of the monoplane type have been produced, having some feature distinct from existing forms. While all of these have flown successfully, few of them have made any effort to be classed among the contestants for honors at the various meets.
One of these, the Fairchild monoplane, shows resemblances to the R-E-P, the Antoinette, and the Bleriot machines, but differs from them all in having two propellers instead of one; and these revolve in the same direction, instead of in contrary directions, as do those of all other aeroplanes so equipped. The inventor claims that there is little perceptible gyroscopic effect with a single propeller, and even less with two. The propeller shafts are on the level of the plane, but the motor is set about 5 feet below, connections being made by a chain drive.
The Beach type of the Antoinette, an American modification of the French machine, at the Boston Exhibition, 1910.
The Burlingame monoplane has several peculiarities. Its main plane is divided into two wings, each 10 feet in spread and 5 feet in depth, and set 18 inches apart at the body. They are perfectly rigid. The tail is in two sections, each 4 feet by 5 feet, and set with a gap of 6 feet between the sections, in which the rudder is placed. Thus the spread of the tail from tip to tip is 16 feet, as compared with the 21½ foot spread of the main plane. The sections of the tail are operated independently, and are made to serve as ailerons to control the lateral balance, and also as the elevator.
The Cromley monoplane, another American machine, is modelled after the Santos-Dumont Demoiselle. It has a main plane divided into two wings, each 9 feet by 6 feet 6 inches, with a gap of 2 feet between at the body; the total area being 117 square feet. At the rear of the outer ends are hinged ailerons, like those of the Farman biplane, to control the lateral balance. The tail is 12 feet in the rear, and is of the “box” type, with two horizontal surfaces and two vertical surfaces. This is mounted with a universal joint, so that it can be moved in any desired direction. The complete structure, without the motor, weighs but 60 pounds.
The Chauviere monoplane is distinct in having a rigid spar for the front of the plane, but no ribs. The surface is allowed to spread out as a sail and take form from the wind passing beneath. The rear edges may be pulled down at will to control the lateral balance. It is driven by twin screws set far back on the body, nearly to the tail.
The Morok monoplane at the Boston Exhibition. It has the body of the Bleriot, the wings of the Santos-Dumont, and the sliding wing tips of the Pfitzner.
The smallest and lightest monoplane in practical use is that of M. Raoul Vendome. It is but 16 feet in spread, and is 16 feet fore and aft. It is equipped with a 12 horse-power motor, and flies at a speed of nearly 60 miles per hour. Without the pilot, its entire weight is but 180 pounds. The wings are pivoted so that their whole structure may be tilted to secure lateral balance.
The new Moisant monoplane is built wholly of metal. The structure throughout is of steel, and the surfaces of sheet aluminum in a succession of small arches from the centre to the tips. No authentic reports of its performances are available.
In the Tatin monoplane, also called the Bayard-Clement, the main plane is oval in outline, and the tail a smaller oval. The surfaces are curved upward toward the tips for nearly half their length in both the main plane and the tail. The propeller is 8½ feet in diameter, and is turned by a Clerget motor, which can be made to develop 60 horse-power for starting the machine into the air, and then cut down to 30 horse-power to maintain the flight.
Chapter VII.
FLYING MACHINES: OTHER FORMS.
The triplane—The quadruplane—The multiplane—Helicopters—Their principle—Obstacles to be overcome—The Cornu helicopter—The Leger helicopter—The Davidson gyropter—The Breguet gyroplane—The de la Hault ornithopter—The Bell tetrahedrons—The Russ flyer.
While the efforts of inventors have been principally along the lines of the successful monoplanes and biplanes, genius and energy have also been active in other directions. Some of these other designs are not much more than variations from prevailing types, however.
Among these is the English Roe triplane, which is but a biplane with an extra plane added; the depths of all being reduced to give approximately the same surface as the biplane of the same carrying power. The tail is also of the triplane type, and has a combined area of 160 square feet—just half that of the main planes. The triplane type has long been familiar to Americans in the three-decker glider used extensively by Octave Chanute in his long series of experiments at Chicago.
The Roe triplane in flight.
The quadruplane of Colonel Baden-Powell, also an English type, is practically the biplane with unusually large forward and tail planes.
The multiplane of Sir Hiram Maxim should also be remembered, although he never permitted it to have free flight. His new multiplane, modelled after the former one, but equipped with an improved gasoline motor instead of the heavy steam-engine of the first model, will doubtless be put to a practical test when experiments with it are completed.
Sir Hiram Maxim standing beside his huge multiplane.
Quite apart from these variants of the aeroplanes are the helicopters, ornithopters, gyropters, gyroplanes, and tetrahedral machines.
HELICOPTERS.
The result aimed at in the helicopter is the ability to rise vertically from the starting point, instead of first running along the ground for from 100 to 300 feet before sufficient speed to rise is attained, as the aeroplanes do. The device employed to accomplish this result is a propeller, or propellers, revolving horizontally above the machine. After the desired altitude is gained it is proposed to travel in any direction by changing the plane in which the propellers revolve to one having a small angle with the horizon.
The force necessary to keep the aeroplane moving in its horizontal path is the same as that required to move the automobile of equal weight up the same gradient—much less than its total weight.
The great difficulty encountered with this type of machine is that the propellers must lift the entire weight. In the case of the aeroplane, the power of the engine is used to slide the plane up an incline of air, and for this much less power is required. For instance, the weight of a Curtiss biplane with the pilot on board is about 700 pounds, and this weight is easily slid up an inclined plane of air with a propeller thrust of about 240 pounds.
Another difficulty is that the helicopter screws, in running at the start before they can attain speed sufficient to lift their load, have established downward currents of air with great velocity, in which the screws must run with much less efficiency. With the aeroplanes, on the contrary, their running gear enables them to run forward on the ground almost with the first revolution of the propeller, and as they increase their speed the currents—technically called the “slip”—become less and less as the engine speed increases.
In the Cornu helicopter, which perhaps has come nearer to successful flight than any other, these downward currents are checked by interposing planes below, set at an angle determined by the operator. The glancing of the currents of air from the planes is expected to drive the helicopter horizontally through the air. At the same time these planes offer a large degree of resistance, and the engine power must be still further increased to overcome this, while preserving the lift of the entire weight. With an 8-cylinder Antoinette motor, said to be but 24 horse-power, turning two 20-foot propellers, the machine is reported as lifting itself and two persons—a total weight of 723 pounds—to a height of 5 feet, and sustaining itself for 1 minute. Upon the interposing of the planes to produce the horizontal motion the machine came immediately to the ground.