PRINCIPLES OF FLIGHT
1. The static pressure of gases work…
in all directions
2. Bernoulli’s equation for frictionless, incompressible gases states that…
total pressure = dynamic pressure + static pressure
3. When air flows through a pipe with changing cross sections, the static pressure changes. The total pressure…
does not change
4. If surrounded by airflow (v>0), any arbitrarily shaped body produces…
drag
5. The “angle of attack” is the angle between…
the chord line and the relative airflow
6. All aerodynamic forces can be considered to act on a single point. This point is called…
center of pressure
7. Which answer describes the term “aerodynamic force”?
Sum of the vectors of lift and drag force
8. “Profile depth” is the distance between the…
leading edge and trailing edge of a profile
9. The illustrated profile is a / an…
symmetrical profile
10. The ratio of span and mean chord length is referred to as…
aspect ratio
11. Which wing shape has the highest induced drag?
Rectangular wing
12. When the rigging angle of incidence of a wing is smaller on the outer side than on the inner (on the root), that is called…
geometric twist
13. The start of vortex development is created during which phase of flight?
When lift is being generated during rotation
14. What occurs at the “transition point”?
The change from laminar to turbulent airflow
15. What pattern can be found at the stagnation point?
Streamlines are divided into airflow above and below the profile
16. Which of the following options describes the pressure pattern at a lift-generating wing profile passed by airflow?
Low pressure is created above, higher pressure below the profile
17. The position of the center of pressure at a positively shaped profile…
moves to the trailing edge while the angle of attack becomes smaller
18. A symmetrical profile…
has a non-moving center of pressure
19. Which statement about lift and angle of attack is correct?
Increasing the angle of attack too far may result in a loss of lift and an airflow separation
20. Which statement about the airflow around an aerofoil is correct if the angle of attack decreases?
The center of pressure moves aft
21. The lift on an airfoil can be directly changed during flight…
by changing the angle of attack
22. Which option states a benefit of aerodynamic washout?
At high angles of attack the effectiveness of the aileron is retained as long as possible
23. Where does “separation” on the aerofoil set in and in which direction does it move with increasing angle of attack?
At the profile’s upper side at the trailing edge, movement opposite to the airflow direction
24. Which statement concerning the angle of attack is correct?
A too large angle of attack may result in a loss of lift
25. How do lift and drag change with decreasing air density (all other parameters remaining constant)?
Lift and drag will decrease
26. Lift depends on…
lift coefficient, square of the speed, air density, projected airfoil area
27. The drag coefficient…
cannot be lower than a non-negative, minimal value
28. Which of the following answers characterises a thick profile compared to a thin profile at the same speed? The thick profile generates…
more drag and more lift
29. How does the drag of the aircraft change when the speed is doubled? It…
quadruples
30. Pressure compensation on an aerofoil occurs at the…
wing tips
31. Which of the following options is likely to produce large induced drag?
Small aspect ratio
32. Induced drag is generated…
at the trailing edge of the wing
33. Where is interference drag generated?
At the wing root
34. Pressure drag, interference drag and friction drag belong to the group of the…
parasite drag
35. Which effect does a decreasing airspeed have on the induced drag during a horizontal and stable cruise flight?
The induced drag will increase
36. How do induced drag and parasite drag change with increasing airspeed during a horizontal and stable cruise flight?
Induced drag decreases and parasite drag increases
37. Which body of the same cross-sectional area has the smallest drag with the same inflowing air speed?
Streamlined body
38. How do lift and drag change when approaching a stall condition?
Lift decreases and drag increases
39. During a stall, the lift…
decreases and drag increases
40. The critical angle of attack…
is independent of the weight
41. A strong decrease of lift can suddenly occur…
when getting close to the stall speed
42. The stall warning will be activated just before reaching which speed?
VS
43. With increasing wing load, the minimum flight speed…
increases
44. The “twist” of the aerofoil causes…
the airflow to stall later in the area of the aileron and the induced drag to increase
45. In motorplanes the stall warning is usually activated by a change of…
the stagnation point
46. Which statement regarding a spin is correct?
During recovery the ailerons should be kept neutral
47. How do lift and drag change when setting flaps to a lower position?
Lift increases, drag increases
48. With regard to flaps, which of the following options provides a lift-increasing effect?
Increasing the aerofoil camber
49. What kind of landing aids may not be retracted suddenly near the ground?
Flaps
50. A take-off with flaps in take-off position causes…
a shortening of the take-off run
51. Which effect (among others) causes lift to increase when extending the landing flaps?
Enlargement of the profile camber
52. How does extending the flaps to landing position affect the final approach (engine idle)?
Minimum speed is smaller, the glide path is steeper
53. When taking off with the flaps extended (take-off position)…
the take-off ground roll is shortened
54. The laminar layer on the aerofoil is located between…
the stagnation point and the transition point
55. What types of boundary layers can be found on an aerofoil?
Laminar layer at the leading wing areas, turbulent boundary layer at the trailing areas
56. Which answer explains the term “boundary layer”?
The layer in which the airflow speed increases from zero up to full speed of the airflow
57. The laminar boundary layer is situated between…
stagnation point and transition point
58. In icing conditions, at which point will the most ice arise on an aeroplane?
On all frontal areas of the airframe, the wings, and the tail
59. What structural item provides lateral stability to an airplane?
Wing dihedral
60. Which statement describes a situation of static stability?
An aircraft distorted by external impact will return to the original position
61. Which force does NOT act during straight and level flight?
Centrifugal force
62. Stability around the lateral axis (longitudinal stability) is achieved by…
the effects and construction of the elevator unit
63. Stability of the vertical axis can be achieved…
by the vertical tail and the fuselage shape
64. Which constructive feature provides longitudinal stability to an airplane in normal configuration (empennage at tail)?
Downforce at the elevator
65. “Longitudinal stability” is referred to as stability around which axis?
Lateral axis
66. What is the purpose of the horizontal stabiliser?
Stabilising the aircraft around the lateral axis
67. Stability around which axis is strongly influenced by the center of gravity’s position?
Lateral axis (Longitudinal stability)
68. What structural item provides directional stability to an airplane?
Large vertical tail
69. Rotation around the vertical axis is called…
yawing
70. The movement around the vertical axis of the aircraft is called…
yawing
71. The critical angle of attack…
is not changed by different aircraft weights
72. The elevator moves an aeroplane around the…
lateral axis
73. The elevator deflection for a specific maneuver…
is increased with a front centre of gravity
74. How can a pilot maintain the altitude during a co-ordinated steep turn?
The elevator is pulled accordingly
75. What has to be considered with regard to the center of gravity position?
Only correct loading can assure a correct and safe center of gravity position
76. Deflecting the rudder to the left causes…
yawing of the aircraft to the left
77. The adverse-yaw effect can occur…
with aileron deflection during slow-flight conditions
78. Which control affects primarily the movement around the longitudinal axis?
Aileron
79. Differential aileron deflection is used to…
keep the adverse yaw low
80. What is the advantage of differential aileron movement?
The drag of the downwards deflected aileron is lowered and the adverse yaw is smaller
81. Which answer describes the term “adverse yaw momentum”?
A yawing momentum opposite to the direction of the rolling momentum
82. The aerodynamic rudder balance…
reduces the control stick forces
83. What is the function of the static rudder balance?
To prevent control surface flutter
84. During cruise flight with constant power setting, an aircraft shows a permanent tendency to raise the nose. How can this tendency be eliminated?
By deflecting the elevator trim tab upwards
85. What is a bendable trim tab?
A fixed tab attached to the rudder or the aileron
86. The trim tab at the elevator is deflected upwards. In which position is the corresponding indicator?
Nose-down position
87. What describes “wing loading”?
Weight per wing area
88. The maximum permissible speed for an aircraft…
must never be exceeded
89. Which answer describes the “manoeuvring speed”?
Maximum speed with which abrupt, full control deflection is permitted
90. Through which factor listed below does the load factor increase during cruise flight?
An upward gust
91. Through which factor listed below does the load factor decrease during cruise flight?
A downward gust
92. Which statement regarding the “constant-speed propeller” is correct?
The set RPM is kept constant by the motor power (MAP)
93. The change in pitch at a propeller blade from the root to the tip ensures…
a nearly constant load by a constant effective angle of attack over the entire length of the blade
94. After an engine failure, the windmilling propeller…
generates drag rather than thrust
95. During a descent at idle power with constant speed, the propeller lever is moved backwards. How do the propeller pitch and sink rate change?
Propeller pitch is increased, sink rate is decreased
96. How is the spin influenced when power is added during a left spin with a clockwise spinning engine?
It is enforced
97. Which answer defines the term “wing load”?
Mass of the aircraft per wing surface area
98. After increasing the angle of attack during flight with best gliding speed, initially…
lift and drag increase
99. How is the balance of forces affected during a turn?
Lift force must be increased to compensate for the sum of centrifugal and gravitational force
100. The spin tendency of an aircraft is greater…
with an aft center of gravity position