Aeronautics

AN UNDERSTANDABLE PRESENTATION OF
INTERESTING AND ESSENTIAL FACTS
IN AERONAUTICAL SCIENCE

By CHARLES. B. HAYWARD

MEMBER, SOCIETY 0F AUTOMOBILE ENGINEERS; MEMBER, THE AERONAUTICAL
SOCIETY; FORMERLY SECRETARY, SOCIETY OF AUTOMOBILE ENGINEERS;
FORMERLY ENGINEERING EDITOR, THE AUTOMOBILE

TYPES OF AEROPLANES

Per horse-power and 3.1 pounds per square foot of surface. The aspect ratio is 2.7 to 1.
Bleriot XI. In 1906, M. Louis Bleriot constructed and flew the first successful monoplane built. The two years following were devoted to experimental work, during which period a number of various modifications of the original were built until, in 1908, Bleriot succeeded in making a number of extended flights in his large monoplane, No. 8 Bis. In July, 1910, he made his sensational cross- channel trip, starting from Calais and landing near Dover. This flight was accomplished in the No. XI type machine, Fig. 32, a small one passenger monoplane which is very simple and has come into widespread use abroad. Delagrange, Le Blanc, De Lesseps, Le Bion, Balsan, and Guyot are among some of the noted French aviators who have flown Bleriot monoplanes, two of whom have been killed in their operation. More than one hundred and fortyof these machines were manufactured and sold during the year ending with August, 1910.
Frame. The frame consists essentially of a long central body of tapering construction to which the planes and rudder are attached. The framework is very lightly but strongly built of wood and is cross braced with steel wires throughout.
Supporting Plane. The main plane is placed at the forward part of the central frame and is divided in half, each section being mounted on either side of the central frame by socket joints. The halves are thus readily detachable at that point and when not in use are dismounted and placed in a vertical position along the frame so as to make the machine as a whole occupy very little room. The surfaces consist of wood ribs covered both above and below by Continental rubber fabric. The curvature is more pronounced than in most other types, with the exception of the Demoiselle, and a sharp front edge is obtained by the use of aluminum sheathing at that point. The two halves of the main plane are set at a slight dihedral angle. Their spread is 28.2 feet, depth 6.5 feet, and surface area 151 square feet. They are braced both above and below by steel wires led to the central frame.
Direction Rudder. The direction rudder consists of a very small plane having only 4.5 square feet of area and is placed at the extreme rear. It is controlled by a foot in the manner already described in some of the foregoing machines.

Elevation Rudder. The elevation rudder is divided into two parts, one half being mounted at each extremity of a fixed horizontal keel. It has 16 square feet of surface and is operated by the longitudinal movement of a bell crank device. This takes the form of , universally-pivoted lever placed in front of the operator, and normally vertical. At the lower extremity of the lever is fixed , dome or hood-shaped piece of metal to which the wires are attached at the same time protecting them from entanglement in the aviators feet. To ascend the aviator pulls the lever toward him, and to descend pushes it from him.
Transverse Control. Lateral equilibrium is maintained by warping the main planes, the structure of the latter enabling them to be twisted as in the Wright machine, though in this case they wart about the bases which are rigidly attached to the main frame by the socket joints mentioned. The two halves are warped inversely by the side to side motion of the bell crank, i. e., if the machine should tip up on the right, then the bell crank would be moved to the right, This would increase the incidence of the lowered side and at the same time decrease that of the raised side, thus righting the machine The combination of this side to side movement of the bell crank with the movement of the foot lever controlling the direction rudder is used in turning.
Keels. To preserve the longitudinal stability, a single, fixed horizontal keel is placed at the rear. Its area is 17 square feet.
Power Plant. The power plant is a three-cylinder, fan-shape Anzani motor, developing 23 horse-power. It is of the air-cooled type and is placed at the forward end of the central frame. It drives, a two-bladed wood propeller of 6.87 feet in diameter by 2.7-foot pitch direct at 1,350 r.p.m. Most of the more recent Bleriot monoplanes have been fitted with 50-horse-power Gnome, seven- cylinder rotary, air-cooled motor.
General. The machine is mounted on an elastic chassis with two large rubber tired wheels forward and a small wheel rear. The springs are made of thick rubber rope, affording great elasticity and strength with small weight. The aviator's seat is back of the main plane.
The total weight is from 650 to 720 pounds and the speed is 36 miles per hour with the Anzani motor and 48 miles per hour with the Gnome motor; 29 pounds are lifted per horse-power and 4.5 pounds per square foot of surface, this ratio being unusually high. The aspect ratio is 4.35 to 1.

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Later Types. In the later Bletiot machines, the elevating rudder is of different form, being attached at the rear end of a tapering keel much larger than that formerly used. The small wheel at the rear has been replaced by a skid and the overall length of the central frarne has been shortened considerably. The regular one-passenger type of this monoplane has further been altered to the new No. XI Bis, in which the sectional curvature of the planes has been. made very nearly flat on the under side. This change has been found to

Fig. 33. Bleriot Two-Passenger Monoplane

greatly decrease the dynamic resistance of the machine without seriously impairing its lift. There are two new models of this machine which have been very successful. They are the No. XI 2 Bis, a two- or three-passenger machine, Fig. 33, and the No. XI racing model, Figs. 34 and 35. The former has a spread of 36 feet, a depth of 7.6 feet, a surface of 270 square feet, and a weight in flight of about 990 pounds. In other respects it resembles the No. XI Bis. 19.8 pounds are carried per horse-power and 3.68 pounds per square foot of surface. The aspect ratio is 4.75 to 1. The type of course, or No. XI racing model, is the machine on which Morane established the record of almost 69 miles per hour. It has a very short body, flat planes, and a reinforced frame. The surface has been reduced to 129 square feet and it is equipped with one of the new 100-horse-power,

Fig. 34. Bleriot Racing Model in Flight

fourteen-cylinder Gnome, rotary, air-cooled motors. The total weight is about 750 pounds; only 7.5 pounds, are carried per horse- power and as much as 5.76 pounds are lifted per square foot of surface.

Fig. 35. Bleriot Rounding a Pylon in International Race for Gordon-Bennett Cup

Bleriot XII. The Bleriot XII is a passenger-carrying type which differs in construction from those just described. With one of these large machines, M. Bleriot made the first flight in an aeroplane carrying three passengers. It has since come into general use, more than thirty of them having been built.
Frame. The long central frame of wood, Fig. 36, braced in every panel by steel cross wires, is very deep forward and tapers gracefully to a point at the rear.
Supporting Plane. On the upper deck of the central frame at the front is placed the main plane which is continuous and perfectly horizontal. Its structure is similar to that of the No. XI and it is braced by a number of wires from the frame. The spread is 30.2 feet, the depth 7.6 feet, and the total area 228 square feet.
Direction.Rudder. A single surface placed at the rear extremity of the vertical keel is used for this purpose. Its area is only 9 square feet and it is operated in the same manner as on the No. XI.
Elevation Rudder. The elevation rudder also consists of a single surface of 20 square feet area and placed at the extreme rear. It is operated by the movement of a bell crank, as already described.
Tranverse Control. The main surfaces are warped inversely, exactly as in the No. XI, a small surface under the aviator's seat also assisting in the lateral balancing. A horizontal keel of 21 square feet area is placed on the framework at the rear, but some what forward of the elevating rudder.
Power Plant. The power plant consists of a 60-horse-power, eight-cylinder E.N.V., air-cooled motor, placed on the frame under the main plane. By means of a chain transmission it drives an 8.8-foot propeller mounted on a shaft at the edge of the main plane. The propeller has an unusually long pitch-9 feet-and turns at only 600 r.p.m.
General. The mounting is similar to that of No. XI, while the seat or bench for three persons is placed under the main plane and back of the motor. The total weight is from 1,150 to 1,300 pounds; speed 48 miles per hour; 21 pounds are lifted per horse- power and 5.3 pounds per square foot of surface. The aspect ratio is 4 to 1. Bleriot is one of the most prolific designers of monoplanes, and it would require a volume to describe them. The Bleriot Limousine or "aerial taxi" is described under special types.
Grade. Herr Grade has the distinction of being one of the first German aviators to design and build an aeroplane.

Fig.21 Sections of Main Supporting Planes of Well-Known Types of Aeroplanes Shown in London, 1910