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Flashcards in Chapter 2 Aerodynamics Deck (128)
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1
Q

The four forces acting on an airplane are

A

Lift, weight, thrust, drag

2
Q

When are the four forces that act on an airplane in equilibrium?

A

During unaccelerated flight

3
Q

Airplanes climb because of

A

Excess thrust

4
Q

Lift acts at a ___ degree angle to the relative wind

A

90

5
Q

The minimum forward speed of the airplane is called the ____ speed

A

Stall

6
Q

You can determine the proper climb attitude for your airplane by referring to the

A

Airspeed indicator

7
Q

The chord line is an imaginary line connecting the

A

Leading edge of the wing with the trailing edge

8
Q

The chord line is used to represent

A

The general shape of the wing

9
Q

The definition of chord enables us to understand

A

The angle the wind meets a wing that may vary in size and shape

10
Q

Relative wind results from the motion of the

A

Airplane through the air

11
Q

Relative wind is ___ and ___ to the airplanes motion.

A

Opposite to, equal

12
Q

Relative wind is ___ which way the airplane’s nose is pointed.

A

Independent of

13
Q

The term “angle of attack” is defined as the angle

A

Between the wing chord line and the relative wind

14
Q

An important principle to understand when dealing with angle of attack is that the nose (therefore the wing) can be pointed on an incline that’s ___ the actual climb path.

A

Different from

15
Q

Wings are expressly built to plow through air molecules separating them either above or below while offering little resistance in the ___ direction

A

Horizontal

16
Q

Wind deflected downward by the airfoil creates a/an ___ movement of the wing.

A

Upward

17
Q

Bernoulli figured out that the faster the air flows over a surface, the ___ pressure it exerts on that surface

A

Less

18
Q

Air flowing faster over a curved surface causes a slight ___ in pressure on that surface

A

Decrease

19
Q

High velocity airflow over the wing causes a slight decrease in pressure on the wing’s upper surface. In other words, the pressure on ___ the wing is now ___ than the pressure on bottom of the wing.

A

Top, less

20
Q

Since high pressure always moves toward low pressure, the wing ( which just happens to be in the way) is pushed ___ in the process.

A

Upward

21
Q

Because of the wing’s shape, even at a very small angle of attack, a cambered wing will adds a slight curve and ___ to the wind.

A

Acceleration

22
Q

At a relatively slow speed ( such as during takeoff), the wing’s engineered curve isn’t capable of curving or deflecting enough air ___ the produce the necessary lift for flight.

A

Downward

23
Q

Raising the nose slightly increases the angle of attack which forces the air to undergo an additional ___ greater than that which the ___ of the airfoil can produce.

A

Curve, engineered shape

24
Q

An increased angle of attack permits the airplane to produce the necessary lift for flight at a ___ airspeed.

A

Slower

25
Q

As the angle of attack increases, an airplane can fly at a ___ speed and still develop the necessary lift for flight.

A

Slower

26
Q

As the angle of attack exceeds approximately 18 degrees the air molecules flowing over the wing don’t negotiate the turn very well. When this happens, they spin off or burble into the free air, no longer providing a uniform, high-velocity, laminar airflow over the wing. The wing ___

A

Stalls

27
Q

When the critical angle of attack is exceeded, the airplane will

A

Stall

28
Q

All wings have what?

A

a critical angle of attack

29
Q

If the wing stalls, you need to do one very important thing:

A

Reduce the angle of attack to less than its critical value

30
Q

You can unstall a wing by ___ the angle of attack

A

Reducing

31
Q

You should realize that an airplane can be ___ at any attitude or any airspeed

A

Stalled

32
Q

Whether an airplane exceeds its critical angle of attack is independent of…

A

attitude or airspeed

33
Q

If an airplane stalls, the first step in recovering is to decrease the angle of attack by moving the elevator control ___ or releasing ___ on the elevator control

A

forward, back pressure

34
Q

Once the airplane is no longer stalled it should be put back in the desired attitude while making sure you don’t ___ again

A

Stall

35
Q

Which of the following may indicate the onset of a stall?

A

Stall horn sounding, diminished control response, noticeable buffet

36
Q

When the weight of an airplane is increased, the airplane stalls at ___ indicated speed.

A

a higher

37
Q

An increase in weight (apparent or real) means the wings must develop more ___ to remain airborne

A

lift

38
Q

The critical angle of attack at which the wing stalls ___

A

Never changes, regardless of airplane weight

39
Q

The angle of attack at which an airplane wing stalls will ___

A

remain the same regardless of gross weight

40
Q

Increasing the airplane’s weight will not affect the ___ of attack at which the airplane stalls

A

Angle

41
Q

Which basic flight maneuver increases the load factor on an airplane as compared to straight-and-level flight?

A

A turn

42
Q

If the airplane “feels” twice as heavy as it actually is, then the lift must ___ if the airplane is to maintain altitude.

A

double

43
Q

An increased load factor will cause the airplane to

A

Stall at a higher airspeed

44
Q

When the bank increases, the nose wants to ___

A

Pitch down, which results in the pilot pulling on the elevator to maintain altitude, causing an increased angle of attack

45
Q

Why is it important for a pilot to be especially sensitive to the amount of G-force he or she is experiencing while maneuvering the airplane?

A

Increasing G-force always means an increase in stall speed

46
Q

What are the most important parts of your anatomy for avoiding stalls?

A

Your brain, for planning to avoid steep turns near the ground and your butt for sensing G-force which helps alert you to an increase in stall speed

47
Q

Drag is the airplane’s natural response to an object’s movement through the ___

A

Air

48
Q

Wings are designed to deflect air ___ while offering very little ___ resistance

A

Vertically, Horizontal

49
Q

The two basic forms of drag are:

A

Parasite and induced drag

50
Q

Parasite drag is the result of

A

Friction

51
Q

As airspeed doubles, parasite drag ___

A

Quadruples

52
Q

Induced drag is resistance to motion induced by the wing turning some of its ___ into ___

A

Lift, Drag

53
Q

As the airplane speeds up, induced drag ___ while parasite drag

A

Decreases, Increases

54
Q

When induced and parasite drag curves are added together, they produce the ___ curve

A

Total Drag

55
Q

The lowest spot in the total drag curve is your magic number, a specific airspeed known as the

A

Best L/D speed

56
Q

The sum of the parasite and induced drag curves reveals a point on the total drag curve where drag is at a minimum. the speed associated with this point is

A

The airplane’s maximum power-off glide range

57
Q

The most important rule to remember int he event of a power failure after becoming airborne is to

A

Immediately establish the proper gliding attitude and airspeed

58
Q

In a power-off glide, the best L/D speed allows the airplane to glide a ___ forward distance with a ___ amount of altitude loss

A

Maximum, minimum

59
Q

Gound effect allows an airplane flying close to the runway to become or remain airborne at a slightly ___ speed

A

Lower-than-normal

60
Q

High pressure on the botoom of the wing causes air molecules to move sideways (toward the wingtip) in the direction of ___ pressure on top of the wing. This action is responsible for the creation of ___

A

Lower, wingtip vortices

61
Q

Wing tip vortices rotate which way about the wingtip?

A

Outward, upward and inward

62
Q

Wingtip vortex action increases with an increase in

A

Angle of attack

63
Q

The wingtip vortex not only spirals around the wingtip, it also adds a/an ___ to the air behind and along the wing’s span

A

Downward flow

64
Q

AT higher angles of attack the downward bending of the relative wind in the vicinity of the wing changes the direct of the ___ wind. This newly bent relative wind is often called the ___ relative wind.

A

Relative, Local

65
Q

Recalling that effective lift always acts ___ to the relative wind, when the angle of attack increases, the total lift force tilts ___ slightly.

A

Perpendicular, rearward

66
Q

Floating caused by the phenomenon of ground effect will be most realized during an approach to land when at

A

less than the length of the wingspan above the surface

67
Q

Ground effect results from a/an ___ in induced drag

A

Decrease

68
Q

Ground effect is most likely to result in which situation?

A

Becoming airborne before reaching recommended takeoff speed

69
Q

When operating in ground effect what happens to induced drag?

A

Induced drag decreases; therefore, any excess speed at the point of flare may cause considerable floating

70
Q

If you’re approaching at a speed above the normal approach speed, make it a point to ___ before entering ground effect to prevent an excessive landing roll.

A

Slow down

71
Q

What causes an airplane (except a T-tail) to pitch nose down when power is reduced and controls are not adjusted?

A

The downwash on the elevators from the propeller slipstream is reduced and elevator effectiveness is reduced.

72
Q

As the airplane become airborne and flies out of ground effect, the wing’s downwash…

A

Increases

73
Q

It’s possible, when attempting to climb out of ground effect, to become airborne without sufficient climb speed, then attempt to climb and have the nose ___ slightly

A

pitch up

74
Q

During landing, as the airplane enters ground effect and the downwash diminishes, the nose tends to pitch…

A

Downward

75
Q

Low wing airplanes experience ___ ground effect than their high wing cousins

A

More

76
Q

Extending or retracting flaps changes the wing’s ___ and ___ characteristics.

A

Lift, drag

77
Q

Lowering flaps lowers the trailing edge of the wing, ___ the angle the chord line makes with the relative wind. This increases the wing’s lift.

A

Increasing

78
Q

When the flaps are lowered, the lowered trailing edge ___ the curvature on part of the wing, resulting in increased air velocity over the wing’s upper surface.

A

Increases

79
Q

Because of the larger angle of attack and greater curvature, flaps provide you with ___ lift for a given airspeed

A

More

80
Q

What’s the reason for putting flaps on airplanes

A

To create the lift necessary to maintain flight at slower airspeeds

81
Q

If the wind is gusty, you might use ___ flap extension than in non-gusty conditions.

A

Less

82
Q

The beginning of the white arc is known as the…

A

Power-off, full-flap stalling speed

83
Q

What is one purpose of wing flaps?

A

To enable the pilot to make steeper approaches to a landing without increasing the airspeed

84
Q

One of the main functions of flaps during approach and landing is to…

A

Increase the angle of descent without increasing the airspeed

85
Q

What force makes and airplane turn?

A

The horizontal component of lift

86
Q

Tilting the total lift force while in a turn means ___ lift is available to act vertically against the airplane’s weight.

A

Less

87
Q

Which axis runs through the center line of the airplane form nose to tail?

A

Longitudinal

88
Q

Airplanes roll about what axis?

A

The Longitudinal axis

89
Q

Which axis runs from wing tip to wing tip, sideways

A

lateral axis

90
Q

Airplanes ___ about their lateral axix

A

Pitch

91
Q

The purpose of ailerons is to ___ the airplane in the direction you desire to turn

A

Bank

92
Q

Ailerons function to allow the right and left wings to develop ___ lift

A

different amounts of

93
Q

When the control wheel (or stick) is turned to the right or left, the ailerons simultaneously move in ___.

A

different directions

94
Q

Adverse yaw is

A

an undesirable byproduct of turning.

95
Q

What is the purpose of the rudder on an airplane?

A

To control Yaw

96
Q

Not using the rudder during a turn will result in ___ turn

A

An uncoordinated

97
Q

As the airplane slows down and enters a stall, which of the following three control surfaces is the last to lose control authority?

A

Rudder

98
Q

Applying forward pressure on the control wheel (or stick) deflects the elevator ___ causing the tail to ___.

A

Downward, rise

99
Q

The purpose of the trim tab is to ___ control pressure required of the pilot

A

eliminate

100
Q

Which direction does the trim tab move relative to the primary control surface it affects?

A

Opposite

101
Q

In what flight condition is torque effect the greatest in a single-engine airplane?

A

Low airspeed, high power

102
Q

The left turning tendency of an airplane caused by P-factor is the result of the …

A

Propeller blade descending on the right producing more thrust than the ascending blade on the left

103
Q

P-factor is more likely to cause the airplane to yaw to the left…

A

at high angles of attack

104
Q

In what flight condition must an aircraft be placed in order to spin?

A

Stalled

105
Q

During a spin to the left, which wing(s) is/are stalled?

A

Both wings are stalled

106
Q

A typical situation that often results in a spin occurs when …

A

A pilot overshoots the turn to the final approach and applies rudder to align the nose with the runway while holding the bank angle constant with aileron.

107
Q

Parasite drag is caused by …

A

friction of protruding airplane parts with the air

108
Q

Generally speaking, parasite drag

A

is a result of the design of an airplane and there is little the pilot can do to reduce it

109
Q

As an airplane’s airspeed doubles, parasite drag…

A

Quadruples

110
Q

Induced drag is

A

the rearward pull of the total lifting force.

111
Q

At small angles of attack induced drag is at its highest or lowest point?

A

lowest

112
Q

If you are trying to reach a destination on limited fuel…

A

Fly at the airplane’s maximum range speed

113
Q

A good reason to use maximum endurance speed is..

A

to minimize fuel consumption, e.g., while waiting for the weather to clear

114
Q

The maximum endurance speed is always ___ the maximum range speed

A

less than

115
Q

in the “region of reversed command,” slower level flight requires…

A

more power

116
Q

To maintain an airplane’s best L/D (lift over drag ratio), a decrease in weight requires

A

A decrease in airspeed

117
Q

You can determine an airplane’s best glide speed

A

by referring to the POH or the owner’s manual.

118
Q

To prevent structural damage to the airplane during turbulence,

A

Maintain flight at or below the airplane’s design maneuvering speed.

119
Q

Which V-speed represents maneuvering speed?

A

Va

120
Q

With respect to the certification of aircraft, which are categories of aircraft?

A

Normal, Utility, Acrobatic

121
Q

The amount of excess load that can be imposed on the wing of an airplane depends upon the…

A

Speed of the airplane

122
Q

When the airplane’s weight decreases, the maneuvering speed…

A

decreases

123
Q

What is an important airspeed limitation that is not color coded on airspeed indicators?

A

Maneuvering speed

124
Q

Upon encountering severe turbulence, which flight condition should the pilot attempt to maintain?

A

Level flight attitude

125
Q

How will frost on the wings of an airplane affect takeoff performance?

A

Frost will disrupt the smooth flow of air over the wing adversely affecting its lifting capability.

126
Q

Why is frost considered hazardous to flight?

A

Frost spoils the smooth flow of air over the wings, thereby decreasing lifting capability.

127
Q

How does frost affect the lifting surfaces of an airplane on takeoff?

A

Frost may prevent the airplane from becoming airborne at normal takeoff speed.

128
Q

Frost on the airfoil ___ the airplane’s stalling speed

A

Increases