highspeedaerodynamics

1. Advanced Aerodynamics

2. Fundamental Flight Maneuvers
• Straight and Level
• Turns
• Climbs
• Descents

3. Four Aerodynamic Forces
• Lift
• Thrust
• Drag
• Weight
• When are they in equilibrium?

4. Four Aerodynamic Forces
• In steady-state or unaccelerated
straight and level flight
• What happens when you initiate
a climb?

5. Four Aerodynamic Forces
• Lift briefly exceeds weight.
• Rearward component of the Lift
adds to drag
• Upward component of Thrust is
called the Lift of Thrust

6. Four Aerodynamic Forces
• Once the climb is established,
the forces are again balanced

7. Lift
• Which of Newton’s laws of
motion are used to describe lift?

8. Lift
• Second law of motion says that a
force results whenever a mass is
accelerated F = ma
• Third law states for every action
there is an equal and opposite
reaction

9. Bernoulli’s Principle
• As the velocity of a fluid
increase, its internal pressure
decreases
• High pressure under the wing and
lower pressure above the wing’s
surface

10. Lift
• In what direction does lift act?
• Perpendicular to the relative wind
• Drag acts parallel to the flight
path in the same direction as the
relative wind

11. Lift
• Angle of incidence
• Angle of attack
• Washout

12. Lift Equation
• L = CLV2
S
• If the angle of attack and other
factors remain constant and
airspeed is doubled lift will be
four times greater

13. Controlling Lift
• What are four ways commonly
used to control lift?

14. Controlling Lift
• Increase airspeed
• Change the angle of attack
• Change the shape of the airfoil
• Change the total area of the
wings

15. Angle of Attack
• Directly controls the distribution
of pressure acting on a wing. By
changing the angle of attack,
you can control the airplane’s
lift, airspeed and drag.

16. Angle of Attack
• Angle of attack at which a wing
stalls remains constant
regardless of weight, dynamic
pressure, bank angle or pitch
attitude.

17. Angle of Attack
• When the angle of attack of a
symmetrical airfoil is increased,
the center of pressure will
remain unaffected.

18. Angle of Attack
• At high angle of attack,
pressure increases below the
wing, and the increase in lift is
accompanied by an increase in
induced drag.

19. Flaps
• What are the four types of flaps
found on general aviation
aircraft?

20. Flaps
• Plain
• Split
• Slotted
• Fowler

22. Leading Edge Devices
• Slot
• Slats
• Leading Edge Flaps

24. Drag
• Induced drag is a by-product of
lift and is greatly affected by
changes of airspeed.

25. Wing Planform
• Name several wing shapes and
their advantages?

26. Wing Planform
• Elliptical - Excellent load
distribution for high-G
maneuvering and low drag for
high speeds
• Rectangular - stall first at root,
least expensive

27. Wing Planform
• Tapered - Favorable stall
characteristics with good load
distribution, saves weight
• Delta - supersonic flight

29. Wing Planform
• How do you find the Aspect
Ratio of an airplane?

30. Wing Planform
• Found by dividing the
wingspan by the average cord.
• What is a typical aspect ratio
for typical training aircraft?
• Gliders?

31. Wing Planform
• Gliders - 20 to 30
• Training Aircraft - 7 to 9

32. Wing Planform
• What is sweep?
• A line connecting the 25% cord points of all
the wing ribs which is not perpendicular to
the longitudinal axis of the plane is said to
be swept
• The sweep can be forward but most are back

33. Wing Planform
• What is a device that is used to
block or diffuse wing tip
vortices?

34. Wing Planform
• Winglets
• Winglets can increase fuel
efficiency at high speeds at
altitudes by as much as 16 to
26%

36. Ground Effect
• Where is ground effect found?

37. Ground Effect
• Within one wingspan of the
ground
• An airplane leaving ground
effect will experience an
increase in what kind of drag?

38. Ground Effect
• Induced Drag
• Induced Drag is only about half
of its usual value when the
wing is at 10% of its span
above the ground

39. Drag
• What kind of drags rate of
increase is proportional to the
square of the airspeed?

40. Drag
• What kind of drags rate of
increase is proportional to the
square of the airspeed?
• Parasite Drag
• What kinds of drag make up
parasite Drag

41. Drag
• Form Drag - based on the shape
of the plane, how well
streamlined and amount of
frontal area.

42. Drag
• Interference Drag - created when
the airflow around one part of the
airplane interacts with the airflow
around another.
• Skin Friction Drag - surface
friction

43. Total Drag
• The sum of the induced drag and
the parasite drag.
• Total drag is lowest at the
airspeed which produces the
highest ratio of lift to drag
L/Dmax

44. Total Drag
• Best power-off glide range
• Greatest Range

45. High Drag Devices
• Spoilers
• Speed Brakes

46. Spoilers
• What are the advantages of
using spoilers?

47. Spoilers
• Rapid descent without reducing power,
engine stays warm
• Maintain normal descent speed
• Help slow to landing gear extension speed
• Descent rapidly through icing
• Stay at high altitudes longer

48. Thrust
• Opposes drag. If greater than
drag, the airplane is accelerating
• A pound of Thrust must be
available for each pound of
drag.

49. Thrust
• Power is the rate at which work
is done. It takes less power to
do the same amount of work at
a slower rate.

50. Propeller Efficiency
• High angle of attack at root,
low angle of attack at tip
• Elliptical planform
• High Aspect ratio

51. Max Level Flight Speed
• Intersection of the Power or
Thrust required curve with the
Power or Thrust available
curve.

52. Load Factor
• Ratio between the lift generated
by the wings at any given time
divided by the total weight of
the airplane.

53. Load Factor
• What is the relationship
between a heavily loaded
airplane and stall speed
compared to a lightly loaded
airplane?

54. Load Factor
• A heavily loaded plane stalls at a
higher speed than a lightly loaded
airplane.
• It needs a higher angle of attack to
generate required lift at any given
speed than when lightly loaded.

55. Calculating VA
• VA2 = VA W2 / W1
• VA2 = Maneuvering speed ( at
this weight)

56. Calculating VA
• VA = Maneuvering speed at
Maximum weight
• W2 = Actual Airplane Weight
• W1 = Maximum Weight

57. V-G Diagram
• Relates velocity to load factor
• Applies to one airplane type
• Valid for a specific weight,
configuration and altitude

58. Aircraft Stability
• Static Stability
• Dynamic Stability

59. Aircraft Stability
• Longitudinal Stability
• Stable in pitch or stable about
the lateral axis
• Motion of the plane controlled
by the elevators

60. Aircraft Stability
• Achieved by locating the center
of gravity slightly ahead of the
center of lift
• Need a tail down force on the
elevator

61. Aircraft Stability
• Lateral stability
• Return to wings level following a
roll deviation
• Dihedral
–Low wing aircraft have more
• Sweep

62. Aircraft Stability
• Sweep may be used when
dihedral would be inappropriate
such as in an aerobatic airplane
that needs lateral stability while
inverted

63. Aircraft Stability
• Directional Stability
• Vertical tail and sides of the
fuselage contribute forces which
help to keep the longitudinal axis
aligned with the relative wind.

64. Flight Maneuvers
• Straight and Level
• To maintain altitude while
airspeed is being reduced, the
angle of attack must be
increased

65. Flight Maneuvers
• Climbs
• Transitioning to a climb, angle
of attack increases and lift
momentarily increases
–Thrust acts along the flight path

66. Climb Performance
• Decreases with altitude
• Absolute Ceiling
• Service Ceiling

67. Turns
• What force turns an airplane?

68. Turns
• The horizontal component of lift.
• Load Factor and Turns
• The relationship between angle of
bank , load factor, and stall speed
is the same for all airplanes

69. Turns
• Rate and radius
• Steeper bank reduces turn
radius and increases the rate of
turn, but produces higher load
factors

70. Turns
• A given airspeed and bank
angle will produce a specific
rate and radius of turn in any
airplane
• Adverse Yaw

71. Stalls
• Angle of attack
• Power-on stalls
• Power-off stalls
• Accelerated stall

72. Stalls
• Secondary stall
• Cross-controlled stall
• Elevator trim stall

73. Stalls
• Total weight, load factor, and
CG location affect stall speed

74. Spins
• Incipient spin
• Fully developed spin
• Spin recovery
• What type of spin can result if the
CG is too far aft and the rotation is
around the CG?

75. Spins
• Flat Spin
• Spin Recovery

76. Spin Recovery
• Throttle to idle
• Neutralize the ailerons
• Determine the direction or
rotation
• Apply full opposite rudder

77. Spin Recovery
• Apply forward elevator
• As rotation stops, neutralize the
rudder
• Gradually apply aft elevator to
return to level flight

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

79. A. decrease lift, thus
enabling a steeper-than-
normal approach to be made.
B. decrease the angle of
descent without increasing
the airspeed.
C. provide the same amount
of lift at a slower airspeed

80. One of the main functions of flaps
during the approach and landing is to
C. provide the same amount of lift at
a slower airspeed

81. Which is true regarding the use of flaps
during level turns?

82. A. The raising of flaps increases the
stall speed.
B. The lowering of flaps increases the
stall speed.
C. Raising flaps will require added
forward pressure on the yoke or stick.

83. Which is true regarding the use of flaps
during level turns?
A. The raising of flaps increases the
stall speed.

84. A rectangular wing, as compared to
other wing planforms, has a tendency
to stall first at the

85. A. center trailing edge, with the stall
progression outward toward the wing root and
tip.
B. wing root, with the stall progression toward
the wing tip.
C. wingtip, with the stall progression toward
the wing root.

86. A rectangular wing, as compared to
other wing planforms, has a tendency
to stall first at the
B. wing root, with the stall
progression toward the wing tip.

87. By changing the angle of attack of a wing,
the pilot can control the airplane's
A. lift, airspeed, and CG.
B. lift and airspeed, but not drag.
C. lift, airspeed, and drag.

88. By changing the angle of attack of a wing,
the pilot can control the airplane's
C. lift, airspeed, and drag.

89. The angle of attack of a wing directly
controls the
A. amount of airflow above and below the
wing.
B. angle of incidence of the wing.
C. distribution of pressures acting on the
wing.

90. The angle of attack of a wing directly
controls the
C. distribution of pressures acting on the
wing.

91. The angle of attack at which a wing
stalls remains constant regardless of

92. A. dynamic pressure, but varies with weight,
bank angle, and pitch attitude.
B. weight, dynamic pressure, bank angle, or
pitch attitude.
C. weight and pitch attitude, but varies with
dynamic pressure and bank angle.

93. The angle of attack at which a wing
stalls remains constant regardless of
B. weight, dynamic pressure, bank
angle, or pitch attitude.

94. The need to slow an aircraft below VA is
brought about by the following weather
phenomenon:

95. A. Turbulence which causes a decrease
in stall speed.
B. High density altitude which
increases the indicated stall speed.
C. Turbulence which causes an increase
in stall speed.

96. The need to slow an aircraft below VA is
brought about by the following weather
phenomenon:
C. Turbulence which causes an increase in
stall speed.

97. Stall speed is affected by
A. angle of attack, weight, and air
density.
B. weight, load factor, and power.
C. load factor, angle of attack, and
power.

98. Stall speed is affected by
B. weight, load factor, and power.

99. The stalling speed of an airplane is most
affected by
A. variations in airplane loading.
B. variations in flight altitude.
C. changes in air density.

100. The stalling speed of an airplane is most
affected by
A. variations in airplane loading.

101. An airplane will stall at the same

102. A. airspeed regardless of the attitude with
relation to the horizon.
B. angle of attack and attitude with relation
to the horizon.
C. angle of attack regardless of the attitude
with relation to the horizon.

103. An airplane will stall at the same
C. angle of attack regardless of
the attitude with relation to the
horizon.

104. In a rapid recovery from a dive, the
effects of load factor would cause the
stall speed to
A. not vary.
B. increase.
C. decrease.

105. In a rapid recovery from a dive, the
effects of load factor would cause the
stall speed to
B. increase.

106. Recovery from a stall in any airplane
becomes more difficult when its
A.elevator trim is adjusted nosedown.
B.center of gravity moves forward.
C.center of gravity moves aft

107. Recovery from a stall in any airplane
becomes more difficult when its
C.center of gravity moves aft

108. (Refer to figure 2.) Select the correct
statement regarding stall speeds.

109. A. Power-off stalls occur at higher airspeeds
with the gear and flaps down.
B. In a 60° bank the airplane stalls at a lower
airspeed with the gear up.
C. Power-on stalls occur at lower airspeeds
in shallower banks.

110. (Refer to figure 2.) Select the correct
statement regarding stall speeds.
C. Power-on stalls occur at lower
airspeeds in shallower banks.

111. Refer to figure 2.) Select the correct
statement regarding stall speeds. The
airplane will stall

112. A. 10 knots higher in a 45° bank, power-on stall,
than in a wings-level stall.
B. 10 knots higher in a power-on, 60° bank, with
gear and flaps up, than with gear and flaps down.
C. 25 knots lower in a power-off, flaps-up, 60° bank,
than in a power-off, flaps-down, wings-level
configuration.

113. Refer to figure 2.) Select the correct
statement regarding stall speeds. The
airplane will stall
B. 10 knots higher in a power-on, 60°
bank, with gear and flaps up, than with gear
and flaps down.