曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
details.
drag (aerodynamic parameter). An aerodynamic force acting in the same plane as the relative wind
striking an airfoil. Two basic types of drag act on an aircraft in flight: induced drag and parasite drag.
Induced drag is caused by the same factors that produce lift, and its amount varies inversely as the
airspeed. As the airspeed decreases, the angle of attack must increase, and this increases the induced drag.
Parasite drag is caused by the friction of air moving over the structure, and its amount varies
directly as the airspeed. The higher the airspeed, the greater the parasite drag.
drag (helicopter rotor blade movement). Fore-and-aft movement of the tip of a helicopter rotor blade in
its plane of rotation.
Printed from Summit Aviation's Computerized Aviation Reference Library, 2/7/2007
Page 202
drag brace (helicopter rotor component). An adjustable brace used to adjust the blade alignment of a
semirigid helicopter rotor. Drag braces resist movement of the blade about its lead-lag hinge.
drag brace (landing gear component). A brace which supports an aircraft landing gear against loads
trying to force the landing gear backward.
drag chute (aircraft operation). A small parachute attached to the rear of an airplane structure. The drag
chute can be deployed (opened) after the airplane touches down on landing to help it slow down.
drag coefficient (aerodynamics). A dimensionless number used to find the amount of induced drag
produced by an airfoil.
The drag coefficient is determined by the shape of the airfoil section and by the angle of attack.
The coefficient of drag for any airfoil section increases as the angle of attack increases.
dragging brakes (aircraft brake malfunction). A condition in which the brakes do not fully release when
pressure is removed from the brake pedal. The brakes are partially applied all the time, which causes
excessive lining wear and heat.
Dragging brakes can cause serious overheating, and may be caused by a malfunction in the brake
master cylinder or by warped disks.
drag hinge (helicopter rotor component). A hinge in the rotor system of a helicopter that allows the
individual blades to move back and forth in their plane of rotation. This movement helps minimize
vibration. The drag hinge is also called the lead-lag hinge.
drag wire (aircraft structure). A structural wire inside a Pratt truss airplane wing between the spars. Drag
wires run from the front spar inboard, to the rear spar at the next bay outboard. Drag wires oppose forces
that try to drag a wing backward. Each drag wire is crossed by an antidrag wire.
drain (electronics). The electrode in a field effect transistor (FET) through which load current flows. Load
current flowing from the source to the drain is controlled by the amount of voltage applied to the gate. The
drain of an FET corresponds to the collector in a bipolar transistor.
drain can (jet aircraft component). A container in a jet aircraft engine compartment used to collect the
fuel which drains from the main fuel manifold when the engine is shut down.
drain hole (aircraft structure). A small hole in the lowest part of an aircraft structure, used to ventilate
the inside of the structure and to drain any water which collects in this area.
drain plug. A removable plug in the lowest point of a liquid container. The plug is removed to drain the
liquid.
drape (textile characteristic). The ability of a woven fabric to conform to a contoured shape.
draw filing. A method of cutting metal or plastic with a hand file by moving the file crosswise over the
work. Draw filing produces a very smooth finish.
drawing number (aircraft drawing). The number assigned to an aircraft drawing. The drawing number is
located in the title block in the lower right-hand corner of the drawing. Drawing numbers often become the
part number of the part made from the drawing.
drawknife. A woodworking tool consisting of a sharp blade with two handles, one at either end of the
Printed from Summit Aviation's Computerized Aviation Reference Library, 2/7/2007
Page 203
blade, mounted at right angles to the blade. A drawknife is pulled across the work to shave off part of its
surface or to make its edges round.
draw set (riveting tool). A metalworking hand tool used to draw sheets of metal closely together before
they are riveted.
A draw set is a steel bar with a hole drilled in one end to fit loosely over the shank of a rivet. The
rivet is put through the holes in the sheets of metal, and the draw set is placed over the rivet shank. Then
the rivet head is tapped lightly with the rivet set. This procedure draws the sheets of metal closely together
before the rivet is actually driven.
drift (navigation). The term used in navigation for the sideways movement of an aircraft caused by the
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
航空术语词典Dictionary of Aeronautical Terms 中(5)
