ASA Ch 1

Question 1

Chord line

Answer 1

A straight line from the leading edge to the trailing edge of an airfoil

Question 2

Airfoil

Answer 2

A structure or body which produces a useful reaction to air movement

Question 3

Relative wind

Answer 3

The wind felt by an airfoil, created by the movement of air past the airfoil, by the motion of the airfoil through the air, or by a combination of the two

Question 4

Angle of attack

Answer 4

The angle between the chord line of the airfoil and the relative wind

Question 5

Angle of incidence

Answer 5

The angle at which a wing is attached to the fuselage

Question 6

Lateral axis

Answer 6

A line from wingtip to wingtip

Question 7

Pitch

Answer 7

Rotation around the lateral axis

Question 8

Longitudinal control

Answer 8

Control of pitch, aka longitudinal stability

Question 9

Longitudinal axis

Answer 9

A line from nose to tail

Question 10

Roll

Answer 10

Rotation around the longitudinal axis

Question 11

Lateral control

Answer 11

Control of roll, aka lateral stability

Question 12

Vertical axis

Answer 12

A line extending vertically through the intersection of the lateral and longitudinal axes

Question 13

Yaw

Answer 13

Rotation around the vertical axis

Question 14

Directional control

Answer 14

Control of yaw, aka directional stability

Question 15

Center of gravity

Answer 15

The point at which an airplane would balance if it were suspended at that point, and the intersection of the lateral, longitudinal, and vertical axes

Question 16

Weight

Answer 16

The downward-acting force of gravity

Question 17

Lift

Answer 17

The upward-acting force which allows the airplane to become airborne

Question 18

Drag

Answer 18

The rearward-acting force which resists the plane’s forward movement

Question 19

Thrust

Answer 19

The forward-acting force created by the propeller

Question 20

Bernoulli’s Principle

Answer 20

As the velocity of a fluid increases, its pressure decreases

Question 21

Parasite drag

Answer 21

That portion of drag produced by the resistance of the air against any part of the plane that does not produce lift

Question 22

Induced drag

Answer 22

Drag created as a by-product of lift

Question 23

Stability

Answer 23

The inherent ability of an airplane to return (or not return) to its original flight condition after being disturbed by an outside force such as rough air

Question 24

Positive static stability

Answer 24

The initial tendency of an aircraft to return or not return to its original position

Question 25

Positive dynamic stability

Answer 25

The tendency of an oscillating airplane to return to its original position relative to time

Question 26

Horizontal lift component

Answer 26

The portion of lift created by the wings which is diverted into a sideways force when the airplane is banked into a turn

Question 27

Vertical lift component

Answer 27

The portion of lift created by the wings which is countering the effects of gravity on the plane

Question 28

Load

Answer 28

The force that must be supported by an airplane structure in flight

Question 29

Centrifugal force

Answer 29

Force which pushes toward the outside of a curve when an airplane is flying a curved path (turns, climbs, descents)

Question 30

Load factor

Answer 30

Load imposed on the wings in flight

Question 31

Stall

Answer 31

Loss of lift sufficient to make flight unsustainable

Question 32

Critical angle of attack

Answer 32

The angle of attack at which a stall occurs

Question 33

Ground effect

Answer 33

When flying one wingspan or less above the surface, the airflow around the wing and wing tips is modified and the resulting pattern reduces downwash and induced drag. Can result in airplane becoming airborne before recommended takeoff speed or floating during approach to land

Question 34

Wake turbulence

Answer 34

Areas behind a moving aircraft in which the air is moving in unpredictable or dangerous ways

Question 35

Wingtip vortices

Answer 35

A byproduct of lift in which air twirls in a vortex behind the tip of each wing