It may be thought that such details as these are unimportant; but when it is remembered that an aeroplane, correctly streamlined, will fly for one-half the power required to fly a machine not so designed, the enormous saving in power will be manifest.
The actual thrust required to lift a model aeroplane is roughly equal to a quarter of its total weight. Thus a model weighing 6 oz. will require 1½-oz. thrust.
CHAPTER II
Types of Model Aeroplanes
With a view to illustrating some of the models described in this book complete, some drawings are given of the more successful designs which have come into prominence during the past eight years. [Fig. 11] shows the Ridley Monoplane, which secured several well-merited rewards in open competition, and is an excellent machine for distance. Birch should be used for the longerons, preferably of channelled section. The main plane is of piano wire, covered with proofed silk, and the elevator is entirely of extremely thin veneer. Bentwood screws are used fairly short in diameter and of long pitch. The machine is capable of flying a quarter of a mile. The Fairey type of model aeroplane typified in [Fig. 12] is a most successful type, and has achieved much in open competition. It has what is known as a floating tail, with no leading stabilising surface, but a small vertical fin is used. This is a practice the waiter is not personally in favour of, as through such a long lever the slightest wind will cause great instability. If a vane or fin must be used, it should be placed as far to the rear of the machine as possible, preferably just behind, or in front of the propellers for pusher machines, and the extreme end of the tail for the tractor type.
The swept-back wing tips should have a negative angle of about two degrees, and the tail should be quite flat in relation to the horizontal.
Fig. 13.—Clarke Type Monoplane
Fig. 12.—The Fairey Monoplane
