PLANE PROPELLERS

Wairarapa Times-Age, 17 April 1940, Page 8

PLANE PROPELLERS

CONTROLLABLE PITCH BLADES. INVENTION OF CANADIAN ENGINEER. SAINT JOHN. Most modern aeroplanes, particularly those now being used by the Allies m the war, are equipped with con-trollable-pitch propeller blades, the invention of a Canadian engineer, Wallace Rupert Turnbull of Rothesay, near this famous port on Canada’s Atlantic coast. This section of the Dominion has given the world many inventors but few have done as much for the advancement of aviation as has Mr Turnbull. When a plane takes off, its propeller is labouring under different aerodynamic conditions than when it is driving the aircraft at top speed, or when the ship is in a steep dive or climb, or encountering innumerable ether conditions of flight. The propeller designed by Mr Turnbull, with its responsive automatic control and unrestricted pitch range, satisfies these stringent requirements. The idea of a controllable-pitch propeller was conceived by Mr Turnbull during the Great War while he was employed as chief inspector in an important aeroplane factory. It took 16 years to perfect. Mr Turnbull is well known to the scientific and aeronautical world as being '.he first* to devise a method of approximating the conditions of a i:ropeller on a moving plane. The re** suit of his investigations, published in the Aeronautical Journal. London, early in the century were far reaching, For this outstanding contribution to the science of flight, he received the medal of the Aeronautical Society, now the Royal Aeronautical Society. The accuracy of his figures have since been substantiated by scientists with specially developed and improved apparatus.