RECOGNITION OF AIRCRAFT

Arawa Guerilla, Issue 8, 1 November 1942, Page 6

RECOGNITION OF AIRCRAFT

2. —Glossary of Descriptive Terms. Following upon our initial discussion of the first principles of aircraft'recognition, we append a list of descriptive terms which will be used in future articles. It is important that these terms should be mastered as a key to the structural features of the various types of aircraft. AILERONSHinged flaps on the trailing edge of the wings, near to the tips, which provide lateral control. One is raised as the other is lowered. By this means the pilot executes the movement known as “banking.” Biplane wings are supported by interplane struts which subdivide the span into sections termed “bays.” CAMBER curvature of the upper or lower surface of a wing or of any aerofoil. CHORD of wing or serofoil from leading to trailing edge measured in a straight line, disregarding camber. CONSERVATORY— description of t(he large glazed roof enclosing the cabin of certain aeroplanes, e.g. Anson, Battle, etc. Also termed “Greenhouse.” ■ COWL, OR COWLING metal cover of streamline form which more or less I encloses the engine. On radial engines the cowling is usually combined with an exhaust collector ring and aircooling ducts. CUT-WAY —Denotes that the regular outline of a wing or elevator is cut away; for example, to enlarge the pilot’s field of view or to give rudder clearance. DIHEDRAL—Or positive dihedral, is the angle between each wing and the horizontal when < the wings are inclined upwards towards the tips. FAIRINGS—Light coverings of streamline form fitted to reduce resistance to airflow. FINThe fixed vertical part of the tail unit to which the rudder is usually hinged. Like the fin of a fish, it increases directional and lateral stability. FLAPS—Movable surfaces at the trailing edge, so arranged that their position and angle in relation to the trailing edge may be controlled by the pilot. They serve as air brakes, enabling the pilot to steepen the landing glide without gaining excessive speed, or as dive brakes. FUSELAGE— body of an aeroplane in which the pilot, crew and load are accommodated and to which other main structural parts are attached. In tlhe “flying wing” type the fuselarge is merged into the centre of a single large wing of special design. IN-LINE ENGlNE.—Consisting of one or more blocks of cylinders arranged in line, as in motor-car engines. The Rolls-Royce “Merlin” is an in-line Vtype liquid-cooled engine, the two blocks pf six cylinders in line being arranged in • V form. The Napier “Dagger” air-cooled engine has four in-line blocks each of six cylinders arranged approximately in H form. LEADING EDGE—The forward edge of wings, tailplane, fins, etc. NACELLES — housings outside the fuselage, ■ which usually enclose the engines of a | multi-engined aircraft. Next Month (3): THE OXFORD.