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Fig. 6. Pusher Type Biplane in Which the Propeller Is Placed Behind the Wings.

Triplanes

Fig. 6-A. Farman Type Pusher Biplane.... Note the Propeller At the Rear of Body, and the Position of the Pilot and Passenger.

Fig. 6-B. The Mann Two-Propeller Pusher Biplane. The Propellers Are Mounted on Either Side of the Body, and Are Driven by a Single Motor Through a Chain Transmission. This Drive Is Similar to the Early Wright Machines.

Fig. 7 is a sketch of a Sopwith Triplane Scout and shows clearly the three superposed wings. The small amount of interplane bracing, and the great aspect ratio, makes this type very suitable for high speed. The body, tail and chassis arrangements are practically the same as those of a biplane. The Curtiss Triplane Scout is the pioneer of this type of machine, although experimental work on the triplane had been performed in England by A. V. Roe many years ago. The Roe triplane was lightly powered and for its time was successful in a way, but the Curtiss is the first to enter into active competition against the biplane scout. Owing to the small span required for a given area, and the possibilities of very light and simple bracing, the triplane is an ideal type for heavy duty machines of the "bombing" species. Enormous triplanes have been made that are capable of a useful load running up into the tons, the large Curtiss and Caproni’s being notable examples. As the triplane is much higher than the biplane of equal area, the interplane bracing is deeper and more effective without causing proportionately higher resistance.