QUITE recently .there have been brought out in Europe several radical types of aeroplanes (baracterized by novel departures from accepted practice; and by far the most interesting ones are the new Antoinette, the Pivot, and the Short “twin” engine biplane. Up to a few months ago, the aviation industry as a whole exhibited work of much ingenuity and cleverness but was wofully lacking in those fine points of pure engineering that go to make any feld of applied science a successful one. With the new types that have been developed abroad, however, it appears that thoughtless copying of a few successful “experiments” is giving way to a more detailed and careful study of the .countless different conditions occurring in the practice of fying, upon which designs with definite ends in view are being perfected. The Breguet biplane and the Nieuport monoplanes may truly be said to represent the pioneer stage of aeronautical engineering, representing as they did, a much higher state of development than any other types. But in France, especially, progress is rapid and it is almost safe to predict that in a short time the Nieuport will be out of date. Many weak features in this type have already been discerned, notably the shape of the body and the landing chassis. At any rate, about the most hopeful sign yet exhibited in the progress of the flying industry is the design and development of aeroplanes with other ends in view than the mere ability to fly and to land without collapsing. Ease of packing for shipment and speed in erection and “tuning up” are factors of great importance that are recei'ng careful consideration. Many dispositions likely to add to safety and a reduction in the number of parts with a view to simplifying and cheapening manufacture are being developed. So it may fairly be said that we are beginning to emerge from the embryo state of aviation to one that is likely to hasten the advent of its full commercialization. Each one of the types described here bears one or more distinguishing features and they have been admirably adapted in practice to the work for w4ich they were designed. The Antoinette Monoplane. The new Antoinette monoplane, designed especially to take part in the French Military Competition, has an unusually radical appearance. This machine, primarily intended for military purposes, is equipped with armor plate protection about vulnerable parts like the motor and chassis, but its most important feature is the total elimination of cross wires, struts and the like. All parts are inclosed-even the wheels and skids-with the result that the resistance is greatly decreased, but the weight increased. In addition a peculiar wing section is used, flat on the under side and curved on the upper side. This type of wing section, as learned from aerodynamical experiments, has a very bad drift resistance at low angles and a very uniform rate of change of the ratio of lift to drift at low angles. The center of pressure as the angle of incidence decreases below 10 degrees does not move back as rapidly as on other shapes. This. type of wing is therefore more stable and of smaller resistance. The distribution of pressure, however, is very uneven, but because of the great strength of the planes themselves, at all points, this is not a detrimental feature. The wings are immensely thick, being entirely braced from the inside. At the body the wings are over two feet thick, something altogether without precedent in aviation. Their thickness decreases toward the tips, which are about 8 inches thick. The shape of each wing is trapezoidal, and they are at a large dihedral angle. This adds to the stability In a calm; in a gusty wind .onditions arise where a large dihedral angle is thought by many to be dangerous. The boat-like body of thjs new type is entirely inclosed and i s capacious to say the least. At the front is the motor, the aviator sits in the body between the two wings, and at the rear are the rudders. The body has a stream line form, and a splendidly shaped prow. A two·bladed Normale propeller at the front pulls the machine forward. The motor is a regular 100·horse-power Antoinette, but the machine will fly with a 60-horse-power motor. The oddest feature of this type is the landing gear, which is entirely inclosed to within a few inches of the ground; the landing wheels at the front are six in number, three on each side of the center, inclosed in what is called a “skirt.” At the rear are two smaller wheels. The dimensions are roughly as follows: Spread, 52¥ feet; area of supporting surface, 602 square feet; length over all, 36 feet; width of wings at tips, over 9 feet, increasing to almost 13 feet at the center. The total weight, including fuel and operator, is nearly 2,400 pounds. The aviator obtains a view beneath him through a glass floor under his seat. For the reduction of resistance, even the exhaust pipes of the engine are inclosed in a stream line shield. This type is certainly birdlike in its appearance and immense in size, but whether the great sacrifices made to eliminate projecting spars or wires are wise remains to be seen. For a purely speed machine it would be wise, without a doubt. There is a large expanse of vertical surface in this machine which is likely to 'make it difficult to handle, especially in a wind. A number of successful flights have already been made, however. The Short Biplane. An aeroplane, equipped with two motors, which has already completed duration flights of over an hour and is therefore capable of fulfilling tle conditions of the Gould Prize, has been built in England by Short brothers. In general outline it is a biplane of the 1910 Farman type, equipped with two 50-horse-power Gnome engines placed centrally one in front of and the other in the rear of the lower main plane at either end of a nacelle or inclosed body. The front motor drives two propellers by chains in opposite directions, precisely as on the Wright biplanes. The propellers are of high pitch, shaped like Wright propellers, but are at the front of the main cell. The rear motor drives a single low pitch propeller at high speed, as on the usual Farman type. It is possible to operate either motor separately or both together. The entire mechanism has worked to the utmost satisfaction, its feasibility being proved beyond a doubt. The aviator sits in the nacelle, a passenger seat at his side. The ruddfr and aileron controls are of the usual Far-man type. The landing chassis and in fact all details of construction are very strong. With the immense extra power available-one motor alone sufficing for ordinary flight-this type has the ability to go fast or slow, and, in addition, on occasion can climb with great rapidity, with its full 100 horse-power. It is to be noted that the axes of the front propellers and the rear one are not on the same level. This is designed to counterbalance the effect on the tail, had by the draft from the rear propeller. As soon as the latter ceases to operate the lifting tail sinks, but the higher position of the axis of thrust of the front propellers at once overcomes this. The dimensions are as follows: Spread, 34 feet; chord, 61A feet; supporting area, 435 square feet; weight in fight, 2,000 pounds. The speeds are said to vary from 35 to over 50 miles an hour, depending on the amount of power used. The Pivot Monoplane. A highly interesting monoplane has recently been brought out in France, known as the Pivot. Its distinguishing features are the use of ailerons for November 11, 1911 SCIENTIFIC AMERICAN 429 transv rse control and the manner in which the planes are braced. The body, of stream line form, suggests a combination of the Deperdussin and Breguet. The motor is at the front covered by a well designed hood. The pilot is comfortably seated at the rear of the main planes which are notched to enable him to have a clear view. The span of the planes is 34:%, feet and their area 174 square feet. The weight of the machine is about 800 pounds in flight. A 45-horse-power Rossel-Peu-geot motor is used. The wing section is of the now familiar Nieuport type, the wedge-shaped entering edge, however, being noticeably larger, and the re- verse curvature at the rear somewhat sharper. For some time, many engineers have been awaiting the monoplane that should cease to have its planes braced by wires-tension members-above the planes, where they never receive any tensile stress except upon landing. As soon as the machine takes to the air with the full pressure acting on the surfaces, the wires above the plane are relieved of all stress and must in consequence hang more or less loosely, thus generating a considerable resistance. It is recognized, however, that in gusty weather, reversals of stress are likely to take place and tension members alone on the under side of the planes would not suffice. There are two ways, however, in which monoplanes can be efficiently braced with the fewest parts and least resistance. The first way is to have compression members alone, capable of taking tension as well above the planes, and the other is to have tension members capable of taking some compression without undue bending below the planes. It is this latter method that is used on the Pivot, two steel tubes below each plane alone sufficing to brace it solidly to the chassis. The results so far have shown this to be an excellent provision. no other bracing wires being necessary. Another novel feature is the use of ailerons instead of warping.
This article was originally published with the title "New Development in Aeroplane Construction"