Farman Biplane
M. PAULHAN DRIVING. plane of his design. This was the first time three people had ever been carried on a flying machine.
The Antoinette machine resembles the Blériot in many respects, each having the long central body, the engine and propeller in front, and the one main transverse plane.
The Antoinette main plane, however, has a more pronounced curve. The elevating plane is fitted to the rear of the central body and below the rudder. Flexible extensions of the main plane are used to increase the stability. This machine has been very skilfully designed, and fitted with the well-tried Antoinette engine with steam FARMAN BIPLANE.
M. PAULHAN ON HIS WAY TO MANCHESTER JUST AFTER LEAVING LICHFIELD. [AERONAUTICS COL. CODY'S AEROPLANE ON LAFFAN'S PLAIN. cooling and direct injection fuel system, it stands out as a well-developed machine.
Curiously enough, M. Latham was for a long time the only aviator to get remarkable results from it, and the point would show that the human factor counts very much.
Biplanes. The double-decked or biplane, with rectangular bearing surfaces, horizontal rudder, or rudders in front, and vertical rudder in the rear, is the most general type in use, and is best exemplified by the Wright and Voisin machines, which are the two main types. The front horizontal rudder is employed to control the upward and downward direction of the machine, but it is much criticised by scientific men. Steering to right or left is accomplished by the rear vertical rudder, and in the Wright machine the warping of the rear end of the main planes is used in conjunction. be The essential difference between machines of this type lies in the form of stabilising device adopted. This can either automatic or under the control of the operator. Its object is to correct those oscillations which otherwise might wreck the machine.
We have to consider in the aeroplane longitudinal and lateral instability. The former is due to the forward and backward oscillations, which tend to pitch the vessel over nose downwards or rudder downwards.
The front horizontal rudder and the rear stabiliser box in the Voisin machine are designed to counteract these movements.
In the Wright machine the front rudders are relied upon.
Lateral oscillations will tend to pitch the machine over sideways to the right or the left. Thus, if a strong gust of wind blew underneath the left wing of the machine, it would lift up this side and depress the other, until the tilt was so aggravated that the machine would almost turn turtle . In the Voisin machine there are vertical panels in the main planes, which, to an extent, automatically check these oscillations, and a stabilising box at the rear made up of smaller vertical and horizontal planes also helps to attain the same end.
The Wrights, however, depend on the skill of the operator, and he is given the power of rapidly warping the ends of the main planes so as to counteract the lateral oscillations. Thus, when a strong wind lifts the left side of the machine, and thus depresses the right wing, the aviator promptly curves the left tips of the machine upwards, thus offering a smaller bearing surface to the wind at this side. The same action automatically curves down the plane tips at the right side, giving a greater bearing surface to the air, or, in other words, increasing the angle of incidence. The air meeting with more resistance at this side tends to lift the right wing, and thus the downward movement caused by the gust of wind is checked, and the machine is brought back to the horizontal.
It will suffice to study in detail two of the principal biplanes, and for this purpose we take the Wright and Voisin machines.
The Wright is characterised by its all-wood frame, and has two main planes about 40 ft. are held wide and 62 ft. deep. These apart by wooden struts, and the whole structure is well braced by wire stays. The planes are mounted on wooden runners, CURTISS BIPLANE.
MR. GLEN CURTISS IN FLIGHT. which take up the landing shocks. In front of the machine is a double horizontal rudder or damper for vertical steering, and at the rear is a double vertical rudder for steering from side to side.
AERONAUTICS] The great feature of the main planes is the warping-gauchissement-arrangement whereby the rear tips at one side are automatically curved upwards when those at the other are curved downwards. This movement is obtained by a lever moving from left to right, or right to left. It is also capable of a fore and aft movement to control the side steering of the machine.
By this ingenious system of control the operator can use the flexing apparatus when executing a turn.
A second lever is fitted which governs the front moveable planes, this giving upward or downward direction to the machine.
The engine is placed close to the operator, who sits at a distance sufficiently far from the centre to balance the weight of the machine has to possess a prearranged and fixed starting point. Later trials have been made with the Wright machine which showed that it could start from the rail without using the weight; and it has even been restarted by gliding over wet grass.
But until some form of wheel support be adopted, the machine will be defective in this respect.
In the Wright machine the warping arrangements are coupled up with the rear vertical rudder so that both are manipulated in turning to right or left. When making a sharp turn in the air, the aviator can heel his machine over to the desired angle, and thus will swing round just like a bicycle or a motor-car on a highly banked track.
Birds, in turning, will be observed to turn A TRIPLANE IN COURSE OF CONSTRUCTION. engine, and it drives two wooden propellers by chain gearing. This method of transmission has been much criticised from the mechanical point of view, but, nevertheless. the Wrights, with a smaller power engine, have attained results which so far have not been equalled by more powerful aeroplanes.
The machine, being mounted on wooden runners, requires an auxiliary apparatus to give it initial velocity. This consists of a form of catapult arrangement, the machine being mounted on a little truck which is rapidly pulled along a fixed rail by a cable when a heavy weight attached to the other end of the rope is suddenly allowed to drop.
The arrangement is ingenious, but as it is not readily portable, it means that the inwards also. The warping device of the Wright machine serves to control this tilting effect and bring the machine back to the normal. By this combined device Mr.
Wright has been able to carry out many extraordinary evolutions in the air, showing a marvellous degree of control in turning quickly.
But the problem of stability in the air has yet to be solved, as even Mr. Wright admits that when a sufficiently strong gust of wind comes he will not be able to contend with it. No really satisfactory stabilising device has yet been invented, and probably the matter will have to be solved in another way by giving the machine such speed that it can move more rapidly than the gust, and thus, consequently, will not be so much subject to its disturbing force. Mr. Lanchester holds that the question of speed will govern all others, and that the very fast machine capable of travelling at eighty or ninety miles an hour will have little to fear on the score of instability. But the question, however, must be carefully worked out, as provision for safety must be made at those times when high speed is not possible.
In the Voisin biplane metal tubing is largely used, and between the main and horizontal plane are vertical panels which give lateral stability. The frame is mounted on a pair of cycle wheels fitted with spring forks. In front the machine has a single horizontal plane for up or down steering, and at the rear is a box tail within which is placed the vertical rudder. A single metal propeller is used, and this is driven from the engine without chain gearing. We thus see essential differences between the Wright and Voisin machines, each point being the subject of much controversy.
Up to the present time the Voisin machine has been unable to excel the Wright aeroplane, and by many critics this is ascribed to the fact that the single pro- [AERONAUTICS peller has to be run at much higher speed than the double propellers of the Wrights; and, as no chain gearing is used, the Voisin engine is run at high speed also. It thus loses its efficiency ere any long distance can be travelled. It is claimed for the Voisin that it has some degree of automatic stability, and that by means of its wheels it can start from almost any place. The latter is undoubtedly a great advantage, and sooner or later the Wrights may also have to adopt a similar starting device, though it will add appreciably to the weight of the machine. The Farman machine is a development of the Voisin, and in 1909 it far surpassed the Wright records. Much of its success was due to a new rotary engine employed by Mr. Farman. are Multiplanes. The multiplanes usually made up of three or more planes mounted one above the other; and there are some other machines in which a number of planes are mounted as radii within a cylindrical vessel. So far, they have achieved no success, and it seems probable that the head resistance they offer to the air is so great that they can never attain a safe speed. Mr.
Horatio Phillips, however, is of the opinion that the multiplane machine with narrow, rectangular surfaces of non-flexible material THE GORDON-BENNETT RACE FROM ZURICH TO GUTOWA, OCT., 1909. AERONAUTICS] will ultimately be the most successful, and no doubt can be entertained as to their great lifting power.
Of machines modelled exactly after the bird shape, there are few modern specimens, the monoplanes being the nearest approach.
The classification " ornithopteres " more exactly applies to wing-flapping machines, in which great wings are actuated in various ways to give both sustaining and propulsive power. This is the so-called natural school, exponents of which urge with rather strained logic that the air can only be navigated by copying the methods of nature in every detail. They argue that the plane surfaces are wrong, that screw propellers are wrong, and that the only right course is to build bird-like shapes and fit them with flapping wings. In naval architecture similar arguments would be proved very fallacious at once.
Hitherto it has been found that the adaptation of the ordinary engine to work complicated reciprocating devices which would give wing-like motion has been very wasteful of power, and, in fact, the mechanical difficulties are so serious that the method has never been proved successful. a We finally come to the helicoptere or vertical lift machine. Whilst aeroplanes use vertical screws to give forward motion, the helicoptere machine is fitted with screws working in horizontal plane approximately, these being designed to lift the machine almost vertically from the ground.
The aeroplane rises gradually by running up a long inclined course, the resistance of the air giving the upward and sustaining effect.
In the helicoptere the weight of the whole machine has to be lifted directly from the ground by sheer propeller power, and this, of course, requires the use of much more powerful screws and engines.
Several helicopteres have been designed which for brief periods have lifted with one or two men from the ground, but they have not been adapted for successful travel in a horizontal direction, and obviously a machine is of little use which can only remain at a fixed point in the air, and has no means of moving horizontally. It has been proposed to adapt the propellers so that they can be tilted to give this forward motion, but many mechanical difficulties are presented, and thus no successful type has yet been evolved. Helicopteres are given very little bearing surface, and thus when the engines fail the machines drop almost vertically to the ground. They are thus not very safe machines to experiment with.
From an analysis of the various types, it is evident that there are many ways of causing a body to rise into and travel through the air, but it is also clear that most of these will have to be rejected for various causes, such as the excessive amount of power required, the limited range of action, COL. SCHACK ON THE HELVETIA COMPETING IN THE