THE COOK NO. 42 WORLD RECORD MODEL
(TWIN PROPELLER HYDROAËROPLANE, 100.6 SECONDS RISING FROM WATER)
During the National Model Aëroplane Competition of 1915 held under the auspices of the Aëro Club of America, a number of new world records were established, one of which was for twin propeller hydroaëroplanes. The credit for this record is due Mr. Ellis C. Cook of the Illinois Model Aëro Club, who succeeded in getting his model hydroaëroplane—which by the way is a rather difficult type of model to operate—to rise from the water and remain in the air for a duration of 100.6 seconds. This model is of the common A frame design with the floats or pontoons arranged in the familiar fashion, two forward and one aft. The model is fairly light, weighing, when complete, 3.33 ounces, ¹⁄₂ ounce of which is made up in rubber strands for motive power. Diagram 14.
The frame is made of two sticks of white pine for side members, each member measuring 38¹⁄₄″ in length, ⁵⁄₁₆″ in depth, by ¹⁄₈″ in width. These are cut to taper toward the ends where they are only ¹⁄₈″ in width by ³⁄₁₆″ in depth in the front and rear respectively. Three “X” strips of streamlined bamboo measuring ³⁄₁₆″ in width by ³⁄₆₄ths of an inch in depth, are used for bracing the frame between the front and rear and are arranged as shown in diagram 14. The propeller bearings are of small streamlined forgings of light weight, and are bound to the rear end of each side member first by gluing, then binding around with thread. The front hook is made of No. 16 piano wire and is bound to the frame as shown in diagram 14. The chassis which holds the floats or pontoons is made of ³⁄₃₂″ bamboo bent to shape and bound to the frame members. By the use of rubber strands the floats are attached to the chassis; the forward ones being attached so that angle may be adjusted.
The main wing has a span of 36″ and a chord of 5″ and is constructed of two white pine beams each 39″ long, with bamboo wing tips. The ribs, seven in number, are also made of bamboo and are spaced along the edges of the wing at a distance of 4¹⁄₂″ apart. The “elevator” or front wing has a span of 14″ and a chord of 3¹⁄₄″, the framework of which is made entirely of bamboo. The entering edge of this wing is given a slightly greater dihedral so that the angle of incidence at the tips is greater than at the center. By this method the added incidence in the front wing is obtained. By the use of rubber bands both wings are attached to the frame.