Biplane

“ It may be said that the low efficiency of the biplane can be somewhat relieved by spacing the upper and lower wings at a considerable distance apart; but if they are spaced at a distance much greater than the chord, it requires extra long struts and wires, and the resistance and weight of these will offset the advantage of wider spacing; so that practically biplane-wing efficiency may be taken as 85 per cent. ”

“ Using such a machine, pilots have flown for long distances with the control levers locked, the biplane adapting itself automatically to the wind-gusts and preserving its equilibrium without aid of any kind. It has neither fore-plane nor tail; it is made to ascend by elevators which are in the form of hinged flaps, or ailerons, and is steered by two rudders at the extremities of the main-planes.
Fig. 59.—Dunne inherently stable Biplane.
A. Hull containing pilot and passenger; B.B. Main-planes; C.C.C.C. Flaps used as elevators; D.D. Side-planes which act as rudders; E. Engine and propeller ”

“ Only slightly known in the United States but well and favourably known in Europe, particularly in France, is the Breguet biplane, which made wonderful records in the French Army tests in 1911. A brief description will show the difference between this machine and others of the biplane type. It has won many prizes for its stability and lifting powers, and also has shown great speed. The framework is mostly metal and is so elastic that it gives under the pulsations for the wind, so that the machine is not so badly strained by gusts as the more rigid kinds. ”

“ He became interested in the experiments of Curtiss and McCurdy at Hammondsport, in 1908, and aided in building the remarkable series of biplanes with which record flights were made. The newer design, known as the Baldwin biplane, is unique in the pivoted balancing plane set upright above the upper plane, a device entirely distinct from the warping or other manipulation of horizontal surfaces for the purpose of restoring lateral balance. ”

“ However, recent developments of the airplane have more or less put efficiency in the background and as a result today the biplane is more popular than the monoplane. In addition to the greater strength of biplane wings their span may be less than the monoplane for the same supporting area. This makes them less unwieldy. Moreover, for certain reasons a biplane machine of high speed may be landed at a lower speed than equivalent monoplanes. ”

“ Through those in front the pilot may glance when descending from a flight, so as to judge his distance from the ground, while the others are utilised by the observer, as he turns to look from side to side. This biplane, and many others, is balanced against sideway roll by ailerons, and not by warping the wings. ”

“ About 90 per cent of all designs are monoplanes and biplanes, and the types are distinguished by their single set of wings or planes or the double planes or wings. Both types have their advantages in use, the biplane being regarded as more stable for certain scouting purposes than the monoplane. It can carry heavier weights—has greater lifting power—but is not capable of as great speed or as easily maneuvered. ”

“ It has been proved a disadvantage of the biplane that, when the main-planes are placed one above another, there is a slight loss of lift owing to the fact that, acting upon the air as they do quite close to each other, a certain amount of interference occurs between them—one tending to disturb the air-stream in which the other moves. ”

“ The monoplane, indeed, captured most of the early records for speed and it was this type of machine that was generally built by the sportsman type of airman, while men like the Wright brothers and others whose aim was to develop an airplane of unusual reliability and suited to many purposes, turned to the biplane and gave many hours and months and years of their time to its improvement. ”

“ No flying animal is half so ugly as the early Wright biplane. In the world of natural fliers beauty and efficiency are one. Purity of line and economy of parts are beautiful and efficient. A good illustration of this may be found in the question of the airscrew. The early French biplanes of the Voisin and Farman type were what would now be called 'pusher' machines ”

“ If there were two kites, with parallel surfaces a few inches apart, united with light framework so that the air would pass between them, we should have a biplane. For many years the great problem in aviation was to get an engine of sufficient lightness and power to propel monoplanes, biplanes and multiplanes at an upward angle through the air. ”

“ The biplane is designed to obtain by a rotary motion the same upward thrust in opposition to the downward pull of gravity as the flapping wings, and the passive outspread wings of birds, and to obtain it by the blades being projected through the air in such a manner as to extract and utilise the practically constant energy of the expansive force of the air. ”

“ As the arrangement of planes in a biplane forms the extremely simple yet enormously efficient box-girder, it is generally considered superior in strength to weight requirements, although for monoplanes of small span it is doubtful if this is so, which affords some indication of the possibilities of the small monoplane as the sporting machine of the days to come. ”

“ He was responsible for the building of the first seaplane to rise from English waters, and may be counted the pioneer of the tractor type of biplane. In 1913 he built a two-seater tractor biplane with 80 horse-power engine, a machine which for some considerable time ranked as a leader of design. ”

“ The Curtiss biplane, which we have seen has had a great deal to do with the development of aviation, is one of the simplest and most successful machines known to-day. The main planes of the regular-sized machines have a spread of 26-1/2 feet, are set 5 feet apart, and have a depth from front to rear of 4-1/2 feet. The total wing area is 220 feet. The direction rudder is a single vertical vane at the rear, which is turned by the steering wheel connected by cables. ”

“ The vacuum made over the lower wing is interfered with by the upper plane, and thus neutralizes somewhat the lifting and flying efficiency of the upper wing. Since a plane must reverse all its stresses when looping, the double supports of the biplane make it less susceptible to doubling up and falling. ”

“ The biplane has been the most largely used of all types in war for two reasons: first, the struts and wires between the planes form a truss structure, and this gives the needed strength; and second, there is less danger of enemy bullets wrecking a biplane in the air because its wing support is greater than that of the monoplane or single-winged machine. ”

“ This was followed in 1910, by a machine on monoplane lines with one fixed plane and two flapping wings. This failed to fly, and in August, 1911, was altered into a biplane. It did not succeed, however. M. Hault is still pursuing the ornithopter question.
HAREL I. Biplane.
Length.—491⁄4 feet (15 m.) Surface.—3441⁄2 sq. feet (32 m2.) Weight.—771 lbs. (350 kgs.) , flying order. Warping wings. Monoplane tail. Motor.—50 h.p. Gnome, mounted just under and forward of the upper wing. Tractor.—1 Chauviere. Elevator placed 1 in front and 1 in rear, H. Farman style. ”

“ The biplane arrangement can be used successfully for spans up to 100 ft., and, assuming that the future commercial machine will necessitate still greater wing area, it is a feasible supposition that the triplane, or even quadruplane systems will be used. Certain modern triplanes have a reputed excellent performance, the carrying capacity and engine power being colossal. ”

“ Most of the fatal accidents in aviation have been caused through mishaps to monoplanes or their engines, and chiefly for this reason the biplane has to a large extent supplanted the monoplane in warfare. The biplane, too, is better adapted for observation work, which is, after all, the chief use of air-craft.
In a later chapter some account will be given of the three types of aeroplane which the war has evolved—the general-purposes machine, the single-seater "fighter", and those big bomb-droppers, the British Handley Page and the German Gotha. ”

“ The automobile experiment naturally suggested the aeroplane, and after much reading of magazines and animated discussions as to the relative advantages of biplanes, monoplanes, gliders, etc., the boys decided to try their skill on a biplane of their own design, a combination of the features and proportions of the Curtiss and Wright machines. ”

“ The biplane forms are being abandoned by model builders, as well as the biplane form of elevating planes. In place of the models made from fifty or more members, we now find excellent models, capable of much longer flights, formed of but a dozen pieces. The builders of model aeroplanes are keeping pace with the development of the man-carrying machines, if they are not passing them, in developing the flying machine of the future. ”

“ After much research and experimentation and many trials and failures, the brothers tested their prototype biplane on the windy dunes of Kitty Hawk, North Carolina. On December 17, their efforts were rewarded and their dream realized when the Wright Flyer rose through the air, soaring for 12 seconds and traveling 120 feet. ”

“ This craft is fitted with an 80-horse-power Gnome engine, and is probably the fastest passenger-carrying biplane of its type in the world. Its total weight, with engine, fuel for three hours, and a passenger, is 1550 pounds, and it has a main-plane surface of 342 square feet.
Not only can the biplane maintain such great speed, but, what is of great importance for observation purposes, it can fly at the slow rate of 30 miles per hour. We have previously remarked that a machine is kept up in the air by the speed it attains ”

“ Because of its similarity to the bird and owing to the lack of struts, etc., to increase the head resistance the monoplane or single-wing plane is the fastest machine. The absence of struts and the few bracing wires brings a greater strain on the wings and increases its chances of breaking. The biplane, with its two parallel wings separated by struts, is more easily braced and proportionately stronger. The lift is also greater, due to the additional wing surface. ”

“ The biplane carries a load of from two and one-half to three and one-half pounds per square foot of surface; the monoplane from three and one-half to six pounds per square foot. The load per horse power in each case is from thirty to forty pounds. In speed the biplane ranges from thirty-five to forty-five miles per hour, as against forty to sixty miles per hour attained by the monoplane. ”

“ This is due to the fact that the engine and propeller, revolving to the left, tend naturally to incline a craft in that direction. The pupil finds as he turns that he must—in addition to putting over the rudder—move the ailerons at his wing-tips; and he needs to make this movement because the biplane, while it is in the act of swinging, begins to heel inwards. The outer plane-ends of a machine, when it is forced thus upon a turn, have indeed a natural inclination to “bank,” or rise. ”

“ What are two or three miles to a wonder of the air that can, if hard pushed, clip along at the rate of a hundred an hour, and perhaps that is far from the capacity of a reliable biplane with a favorable wind. ”

“ This type, which probably originated in England, and at any rate attained to its greatest excellence prior to the War from the drawing offices of the Avro Bristol and Sopwith firms, dealt a blow at the monoplane from which the latter never recovered.
The two-seater tractor biplane produced by Sopwith and piloted by H. G. Hawker, showed that it was possible to produce a biplane with at least equal speed to the best monoplanes, whilst having the advantage of greater strength and lower landing speeds. ”

“ Should the biplane tilt, while flying, say towards the left, the pilot moves his hand-lever sideways towards the right. This is a natural movement, the instinct being to move the lever away from the direction in which the machine is heeling. This movement of the lever has the effect of drawing down the ailerons on the left-hand side of the machine ”

“ Nearly all aeroplanes follow the same general principles of construction. Of course a good deal depends upon the form of aeroplane—whether a monoplane or a biplane. As these two forms are the chief ones, as yet, of heavier than-air machines, it would be well to understand them. The monoplane has single large surfaces like the wings of a bird, the biplane has two large surfaces braced together one over the other. ”

“ The tandem monoplane shown by Fig. 18 is another machine which has scored many successes in the early days of model aeroplaning at the Crystal Palace. Figs. 19, 20, 21, 22 show the Twining hand-launched biplane, a tractor biplane built by the writer, a fuselage biplane (canard or screw behind) , and a Blériot type tractor monoplane. [Pg 18]
A tractor machine is one having the screw in front, and a “canard” or “pusher” machine has its screw behind. It is best to designate the machine by the type formula. Thus, a pusher monoplane with twin screws would be a 1-1-P2-0 type. ”

“ Down and still down the three machines rushed. Suddenly he noticed the slow biplane in front—on an even lower level than himself. It was very close. He saw the pale dot of the face of the man behind the gun. If he swerved he would be under its fire in a moment. ”

“ The regular big biplane of the bomber type carries two propellers with an engine for each propeller. If one motor fails them when flying, about all the other is good for is to make a landing with. By reason of the great lightness of our airplane one good 400 horse-power motor is all we need for pulling purposes. ”