Although the method of determining the balance of an R. O. G. or a model hydroaëroplane is exactly the same as that of a hand launched model, the manner of launching is somewhat different. Instead of holding the model one hand in the center of the frame and the other at the rear as in the case of the hand launched model, in launching an R. O. G. or hydro, the model should be rested upon the ground or water, as the case may be, with both hands holding tightly to the propellers. Then when about to let the model go release both propellers instantly. If the model has sufficient power and it has been properly adjusted it will glide over the surface of the ground or water for a short distance, then rise into the air. Should the model fail to rise into the air additional strands of rubber should be added, after which it should be rewound and a second attempt made.
Should the model fail to respond after the addition of extra rubber, the indications are that something requires further adjustment. Perhaps the pontoons need further elevation if the model is a hydro, or if it be an R. O. G. model the forward wing may require an increase of elevation. In any event the model should be carefully examined and adjustments made where necessary, after which the model should be tested for balance and elevation. If satisfied with the behavior of the model after test flights have been made, another attempt should be made to launch the model from the ground or water.
On no account try to fly the model in the house, or see, supposing the model is of the R. O. G. type, if it will rise from the dining room floor. This advice may seem unnecessary, but it is not so, for there has been quite a number of instances in which the above has been done, nearly always with disastrous results, not always to the model, more often to something of much greater value. The smashing of windows has often resulted from such attempts, but generally speaking pictures are the worst sufferers. It is equally unwise to attempt to fly the model in a garden in which there are numerous obstructions, such as trees and so forth. A wrecked model is very often the result of such experimenting. The safest way to determine the flying ability of any model is to take it out in an open field where its flight is less apt to be interrupted.
WORLD RECORD MODELS
THE LAUDER DISTANCE AND DURATION MODEL
After many months of experimentation Mr. Wallace A. Lauder succeeded in producing a model that proved to be one of his most successful models. But a few years ago flights of 1000 feet with a duration of 60 seconds were considered remarkable. But so rapid has been the development of the rubber strand driven model that to-day it is hardly considered worth while to measure a flight of 1000 feet, especially in contests where models fly over 2500 feet or 3537 feet which was the distance flown by Mr. Lauder’s model during one of the contests of the National Model Aëroplane competition of 1915. Mr. Lauder’s model on several occasions made flights of over 3500 feet with a duration in each event of over 195 seconds. It is therefore to be remembered that this model is both a distance and duration model, both qualities being seldom found in one model.
Reference to the accompanying [drawing] will give a clear idea of the constructional details.
The frame or fuselage consists of two side members 40″ in length, of straight grained spruce. At the center each member is of approximately circular cross section, and is ¹⁄₄″ in diameter. The members taper to about ³⁄₁₆″ at the ends, the circular cross section being maintained throughout. The frame is braced by a strip of bamboo of streamline form, extending from one side member to the other, 18″ from the apex of the frame. The ends of this frame are bent to run parallel to the side members of the frame where they are secured by binding with silk thread and gluing. Piano wire hooks are also secured to the side members of the frame adjacent the ends of the cross brace, and from these hooks extend wires of steel (No. 2 music wire) which run diagonally to the rear brace or propeller spar where they are secured.
Diagram 11