Research Rack: Glossary

aerodynamics - the study of motions and forces of gases on an object

aeronautics - a word that came from the Greek word for "air" and "to sail;" the study of flight and the operation of aircraft

aileron - surface on the outer edge of a wing that moves up and down; controls the roll of an airplane

airfoil - section of a wing, rudder, aileron, or rotorblade used for testing reactions from the air through which it moves

air pressure - the weight of air pressing on a surface

center of gravity - distribution of weight around a balance point

cockpit - the control center where the pilot, instruments, and navigational aids are located

drag - the air resistance acting on airplanes. Drag acts in the opposite direction of thrust. Two types of drag are pressure and skin friction drag

elevator - the part on the tail that helps the aircraft maintain level flight and adjusts the aircraft's pitch; the elevator controls the airplane's nose, tilting it upward or downward

engine - the part of the airplane that provides the power for take-off and landing and supports flight

equilibrium - a condition in which all acting forces (lift, gravity, drag, and thrust) are canceled by one another, resulting in a balanced and stable flight

flaps - retractable trailing edges of a wing that move down to increase wing surface and increase lift on take-off. Located closer to the fuselage than the aileron

force - a push or pull used to lift something, start it moving, or hold it in place against another force, such as gravity

fuselage - the main structural body of an airplane to which the wings and tail unit are attached

gravity - the force of attraction between two objects (such as the force between an airplane and the Earth)

landing gear - wheels, skis, or floats on an aircraft

lift - a force that acts upward against gravity and makes it possible for airplanes, airships, and balloons to rise in the air

pitch - one of the three axes of motion for an airplane; pitch moves the nose up or down in relation to level flight

physics - a science that deals with matter and energy and their actions upon each other in the fields of aeronautics, electricity, heat, light, mechanics, and sound

pressure drag - the drag created when the airflow runs into an object and separates to get around the object

propeller - twisted airfoil or turning blade that is powered by the engine and provides thrust

roll - one of the three axes of motion for an airplane; roll refers to the left and right movement of the fuselage and raises the wings of the airplane up or down

rudder - the parts of the tail surface that control an airplane's yaw; the rudder moves the nose left and right to control the direction in which the airplane turns

skin friction drag - the drag due to the friction between the air and the surface of an object moving through the air

spinner - the part of the shaft that covers the center of the propeller and helps smooth the airflow over the engine

thrust - a forward force that pushes an airplane through the air

wind tunnel - a chamber where air or smoke is blown over an object, such as an airfoil, to calculate its aerodynamic forces, such as lift and drag

wing - an airplane's airfoil; the wing produces lift as the craft moves through the air and has two movable controls: ailerons and flaps

weight - a response of mass to the pull of gravity

yaw - one of the three axes of motion for an airplane; yaw moves the nose of the airplane from side to side