Oneof the most notable results of the National Model Aëroplane Competition of 1915 was the establishing of a new world’s record for flying boats. Considering that the model flying boat is a difficult type of model to construct and fly, the establishing of this new world record of 43 seconds is remarkable. Credit for this performance is due Mr. Robert La Tour of the Pacific Northwest Model Aëro Club, who designed, constructed and flew the model flying boat which is herewith described and illustrated.Diagram 13.
The frame is made of laminated spruce 40″ in length, made of two strips glued together. They are ³⁄₈″ × ¹⁄₈″ at the center tapering to ³⁄₁₆″ × ¹⁄₈″ at the ends. The cross braces are of split bamboo and are fastened to the frame side members by bringing them to a wedge at the ends and then inserting them into slots in thesides of the frame side members and are finally drilled and bound to the latter. The rear brace is of streamlined spruce ¹⁄₄″ × ¹⁄₈″; this butts against the frame side members and is bound to them. The propeller accommodations are made of brass.
The propellers are 10″ in diameter with a 19″ pitch. These are carved from a block of Alaska cedar 1¹⁄₄″ wide by ³⁄₄″ thick. Of course the propellers may also be made from white pine. To turn the propellers 15 strands of ¹⁄₈″ flat rubber are used.
Bamboo about ¹⁄₁₆″ square is used to obtain the outline of the wings. The main wing has a span of 33″ with a chord of 5¹⁄₂″. Split bamboo is used for the making of the 9 ribs. The wing spar or brace is of spruce ³⁄₁₆″ × ¹⁄₈″ and is fastened below the ribs as illustrated indiagram 13. The elevator is constructed in like manner but has a span of only 17″ × 4³⁄₄″ and has only 5 ribs. A block ³⁄₄″ high is used for elevation. Both wings have a camber of ¹⁄₂″ and are covered on the upper side with silk doped with a special varnish and a few coats of white shellac.