Aeroplane Construction and Operation

by John B. Rathbun

Figs. 6-7. Various Motor Arrangements, and Radiator Locations.

Fig. 10. A Type of H. and M. Farman Tractor Fighting Biplane. This Machine Uses a "V". Type Motor, with the Radiator in the Valve Alley. The Gunner and the Machine Gun Are Mounted in the Rear Cock-pit. It Will Be Noted That the Body Is Raised Well Above the Lower Wing So that the Gun Field Is Increased. The Pilot Is Well Ahead of the Entering Edge of the Lower Wing. Courtesy of "Aerial Age."

The fuselage is of excellent streamline form and shows careful study in regard to the arrangement of the power plant. Unlike the majority of machines, the fuselage is raised well above the bottom wing, this being done evidently to increase the range of the gun in the rear cockpit. The increased height allows the gun to shoot over the top plane at a fairly small angle, and the height above the ground permits the use of a very large and efficient propeller without having an excessively high chassis. At the rear the fuselage tapers down to a very thin knife edge and therefore produces little disturbance.

Fig. 11. Radiator Mounted at Leading Edge of Upper Wing. This Type Is Used with the Sturtevant and Lawson Aeroplanes and Is Very Effective Because of the Improved Circulation.

Fig. 11 shows a Sturtevant Training Biplane in which the radiator is mounted at the front edge of the upper plane. This arrangement was originally introduced by the Sturtevant Company in their steel biplanes and has proved a very efficient type for cooling, although the radiator must affect the lift of the top plane to a very considerable extent.

Pilot and Passenger Compartments. These compartments contain the seats, controls, and instruments, and in the military types contain the gun mounts and ammunition. In some battle-planes, the passenger or "observer" occupies the rear seat, as this position gives a wider range of fire against rear or side attacks. This arrangement is true of the H. and M. Farman machine just illustrated and described. In the large German "Gotha" the gunner occupies the rear position and fires through, or above, a tunnel built through the rear end of the fuselage. In some forms of training machines, the pilot and passenger sit side by side instead of in tandem, as this arrangement allows better communication between the pilot and student, and permits the former to keep better watch over the movements of the student. A notable example of this type is the Burgess Primary Trainer. A side-by-side machine must have a very wide fuselage and therefore presents more head resistance than one with the seats arranged in tandem, but with proper attention to the streamline form this can be reduced so that the loss is not as serious as would be imagined from a view of the layout.

The seats may be of several types, (a) the aluminum "bucket" type similar to, but lighter than, the bucket seats used in racing automobiles; (b) the woven wicker seat used in many types of German machines, or (c) the modified chair form with wooden side rails and tightly stretched leather back and bottom. Whatever the type, they should be made as comfortable as possible, since the operation of a heavy machine is trying enough without adding additional discomfort in the form of flimsy hard seats. In the older machines the seats were nothing more than perches on which the pilot balanced himself precariously and in intense discomfort. A few pounds added in the form of a comfortable seat is material well spent since it is a great factor in the efficient operation of the machine. Wicker seats are light, yielding and comfortable, and can be made as strong or stronger than the other types. It seems strange that they have not been more widely adopted in this country.

All seats should be slightly tilted back so that the pilot can lean back in a comfortable position, with a certain portion of his weight against the back of the seat. Sitting in a rigid vertical position is very tiring, and is especially so when flying in rough weather, or on long reconnaissance trips. The backs of the seats should be high and head rests should be provided so that the pilot's head can be comfortably supported against the pressure of the wind. If these head rests are "streamlined" by a long, tapering, projecting cone running back along the top of the fuselage, the resistance can be considerably reduced. This arrangement was first introduced in the Gordon-Bennett Deperdussin and has been followed in many modern machines. In the Deperdussin, the pilot's head was exposed directly to the full blast of the propeller slipstream and a head support was certainly needed. Small, transparent wind shields are now fastened to the front edge of the cockpit openings which to a certain extent shield the pilot from the terrific wind pressure. These are quite low and present little resistance at high speeds.

Fig. 12. Hall-Scott Motor and Side Type Radiator Mounting on a Typical Tractor.

A heavy leather covered pad, or roll, should be run entirely around the edge of the cockpit opening as a protection to the pilot in case of an accident or hard landing. The roll should be at least 3 1/2" in diameter and should be filled with horse hair. All sharp edges in the cockpit should be similarly guarded so that in the event of the pilot being thrown out of his seat, he will not be cut or bruised. Each seat should be provided with an improved safety strap that will securely hold the pilot in his seat, and yet must be arranged so that it can be quickly and easily released in an emergency. In flight the occupants must be securely strapped in place to prevent being thrown out during rapid maneuvers or in rough weather. Buckles should be substantial and well sewed and riveted to the fabric so that there will be no danger of their being torn out. The straps must be arranged so that they will not interfere with the free movement of the pilot, and so that they will not become entangled with the controls. It is best to copy the sets approved by the government as these are the result of long continued experiment and use.

Fig. 13. Deperdussin Monoplane with Monocoque Body. Note the Streamline Form of the Body and the Spinner Cap at the Root of the Propeller.