BRITISH AVIATION NEWS

Otago Daily Times, Issue 21951, 12 May 1933, Page 11

BRITISH AVIATION NEWS

SAFETY AND HIGH SPEED FLAPS AND INTERCEPTOR SLATS. (From Our Own Correspondent.) LONDON, March 23. No device has done more to eliminate the dangers inherent in the stall (or loss of flying.speed) than the British invention known as the Handley Page wing slot. It, is fitted to 80 per cent. o£ all the aircraft in the Royal Air I<orce, and to the maioritv of British commercial and privately-owned aeroplanes, and gome 43 countries overseas have made arrangements for incorporating the device m aircraft constructed or used withm their borders, while a feature of recent aircraft design even outside this country is the number of aeroplanes which employ slotted .wings in conjunction, with wing flaps on the trailing edge, j ' Wing slots, wing flaps, and Interceptor" slats • developed by the Handley Page Company may shortly form part ot the wing structures ol the latest types of military aircraft in all the chief flying countries. In the United States an entire squadron has been equipped recently with aeroplanes which have slotted, wings and interconnected flaps. iNew French and German aeroplanes- have shown what can be gained in speed range by use of interconnected slots and flaps, and in other lands aircraft still in process of manufacture will be similarly fitted. In their adoption of slots and flaps for military aircraft the air.staffs have been influenced by ' a large number ot tactical considerations among which are performance, mobility, and security.

MOBILITY. No matter how great, may be the ingenuity of the aeroplane designer, nor how light the engine for the horsepower developed, nor how fine the streamlining, attainment of high top speed must always bear a relation to landing and take-pit speeds. Though a huge aerodrome with a perfect surface may safely be flown on and off at very high speeds, military aircraft, which have to operate over all kinds of terrain and frequently from small landing grounds, must have reasonably low landing speeds. High landing speeds are out of the question, and the raisin" of the top speed of a military aeroplane by the simple process of increasing landing and, take-off speeds is impracticable. Further, a high landing speed is obviously undesirable in any flying machine; if it can be avoided so much the better. . But the top speed may be increased without pushing up landing and take-off speeds if the wings be fitted with interconnected slots and flaps. " These devices give performance and mobility at the same time. They allow the top speed to be raised without delimiting the aerodromes which the aircraft can _ use and so restricting its field of operations. There remains the problem of security. Wing slots and flaps together markedly affect the gliding angle, thereby increasing the safety of aircraft and improving their general efficiency in all kinds of bad weather flying, as well as helping enormously in forced landings, and in ease of flying control. Without slots and flaps, the gliding angle of an aircraft is defined with strict limits. > With them the pilot can choose his angle; a fully-slotted and flapped aeroplane may be made to glide at any angle of descent between one in twelve and one in six, and at all angles it is fully controllable and perfectly sate. NEW "JOY-RIDING" PLANES. Work is going forward in the Avro factory on four special " Cadet " biplanes ordered by the Scottish Motor Traction Company. They will bring up to 24 the number of new aeroplanes ordered by this organisation within the past year. Ihis summer, in addition to. pleasure-flying, air-taxi work, and newspaper services, the company may inaugurate regular airline services through Scotland and much of Northern England. The new "Cadet planes will be used chiefly in joy-rid-ing." Normally they are two-seater craft, designed in the first place for the inexpensive and efficient training of military pilots. Those concerned in the new order will carry two passengers in an enlarged cockpit forward of the pilot. Power will be supplied by an inverted 130 h.p. air-cooled engine.