The Rocket‐Propelled Aeroplane: A Discussion of the Principles Involved in the Application of Rocket Propulsion

THE rocket‐propelled aeroplane demands the successful combination of two conflicting principles. In fact the problem has been compared with the construction of a ship equally suited for travelling on rivers and navigating the high seas. The principle of the rocket, as that of the aeroplane, is to move by reaction against an accelerated mass. There is a great difference, however, in the manner of application of this principle, as the following two examples will show. A powder rocket of a commercial type has an overall, weight of 140 grammes (453 grammes = 1 lb.); the weight of the shell containing the driving charge is 40 grammes, while the charge weighs approximately 15 grammes. The effective burning time of such a rocket was found to be 0.15 sec.; the thrust during this period being 4.8 legs, or approximately 11 lb. The exhaust speed of the gases (“c”) was calculated to be 453 metres per second; the acceleration 314 metres per second (in other words more than 31 gravities): the altitude 110 metres without considering air resistance. Actually the altitude reached was about 80 metres, or 250 ft.