Natural Stability And The Parachute Principle In Aeroplanes Part 2

[Ill.u.s.tration: FIG. 32.]

In order to cool the engine and keep the air in the car clear, a ventilating pipe is led from the front of the car to the engine, and the air, rushing through this at the speed of the machine, plays over the engine and is conducted out through a large opening and discharged at the back.

The whole of this part of the machine is rigid and braced together by means of struts, though whether made of steel tube or timber, there must always, from the nature of the construction, be a certain amount of elasticity which makes for strength, a great advantage over a construction braced rigidly by non-elastic wires, which snap instead of giving to a sudden strain.

Under the two rigid T-section longitudinals there are a number of elastic laminated wood springs set at an angle, and the lower ends of these are pivoted on to a long elastic skid. This skid is made in laminations, with alternate joints, and starts from the point where the two planes intersect in the front of the machine, which is one of the strongest joints in the whole construction. From this point it bends out in a semicircle to protect the propeller and the front of the machine and car, this portion of it being very elastic by reason of the laminations having free play one upon the other. At the bottom of the semicircle the skid is joined to the slanting skids or springs depending from the bottom of the machine, and here the laminations are bolted together making the skid stiffer. The skid runs the whole length of the machine like the runner of a sledge. On this skid the wheels are sprung with a steel spring lever arrangement, Fig. 33. The shock of landing is, therefore, taken first on the wheels, and should it be sufficiently heavy to cause the skids to touch the ground there is still the series of laminated wood springs to absorb any vibrations and prevent any possible shock to the car. The car is so secure from vibration by reason of these precautions that the whole lower half of the front of it may be made of protected gla.s.s, to enable the pilot to get a clear view of his surroundings.

[Ill.u.s.tration: FIG. 33.]

The dimensions of the full-sized machine are estimated to be as follows:--

Span 20 feet Length 43 feet Parachuting area 500 square feet Efficient lifting area 360 square feet Weight (all up) 800 lb.

It will be understood that though only 360 square feet is counted as efficient for lifting, the whole 500 square feet is efficient as parachuting surface in descending. The weight of the machine compares very favourably with existing machines, and the load 2-1/4 lbs. per square foot, gives plenty of margin for pa.s.senger carrying.

The chief advantages claimed for this machine are:--

(1) Speed.

(2) Stability.

(3) Strength of construction.

(4) Shock absorbing capacity.

It is a practical impossibility for the machine to turn over or be blown over, and it will recover its balance if started at any angle.

If allowed to dive vertically, either tail first or head first, it will recover its position in six times its own length, purely by its own balance, without any effort of the pilot.

LONDON: PRINTED BY WILLIAM CLOWES AND SONS, LIMITED,

GREAT WINDMILL STREET, W., AND DUKE STREET, STAMFORD STREET, S.E.