Aerodynamics Flashcards

1
Q

What are the four forces of aerodynamics?

A
  • Thrust
  • Drag
  • Lift
  • Weight
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is thrust in aerodynamics?

A

Forward force produced by the propeller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define drag in the context of aerodynamics.

A

Rearward force caused by disruption of airflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is lift?

A

Upward force created by air acting on airfoils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does weight refer to in aerodynamics?

A

Downward force caused by gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

State Bernoulli’s principle.

A

Higher air velocity results in lower pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Newton’s third law?

A

Every action has an equal and opposite reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the design of an airfoil.

A

Upper surface is longer than lower surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the result of the airfoil design?

A

Creates higher pressure below, resulting in lift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define angle of attack (AoA).

A

Angle between chord line and relative wind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the relationship between AoA and speed?

A

Greater AoA is needed at lower speeds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

In steady flight, what is true about the forces?

A

All forces are balanced; opposite forces are equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is parasite drag?

A

Drag caused by wind moving around the aircraft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define form drag.

A

Drag caused by wind moving around the aircraft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is interference drag?

A

Drag caused by the intersection of wind streams at 90° angles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What causes skin friction drag?

A

Caused by any non-smooth surfaces on the aircraft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is induced drag?

A

Byproduct of lift, altered by changing AoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe wingtip vortices.

A

Moves out, up, in, around wing tips, then moves outward and down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When are wingtip vortices most prevalent?

A

In heavy, clean, slow aircraft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is ground effect?

A

Interference of ground surface with airflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the effects of ground effect?

A
  • Breaks up vortices
  • Increases performance
  • Reduces drag
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do higher temperature and humidity affect density altitude?

A

Increase density altitude, decreasing performance

Higher temperature and humidity lead to a decrease in air density, which can adversely impact aircraft performance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the CG in aviation?

A

Point where the plane would balance, if suspended

CG stands for Center of Gravity, a critical factor in aircraft stability and control.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the three axes of aircraft movement?

A
  • Lateral - stabilator
  • Longitudinal - ailerons
  • Vertical - rudders

These axes define the orientation and movement of the aircraft in three-dimensional space.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does 'Moment' measure in aviation?
Measures an aircraft's tendency to rotate ## Footnote Moment is calculated as the product of force applied and the distance at which it is applied.
26
How is Moment calculated?
Moment = weight X arm ## Footnote The arm is the distance from the reference point to the applied force.
27
How is CG calculated?
CG = total moment / total weight ## Footnote This formula helps determine the aircraft's center of gravity based on its weight distribution.
28
What is Stability in aviation?
Ability of an aircraft to correct deviations after a disturbance ## Footnote Stability is crucial for safe flight operation and handling.
29
What is Static stability?
Initial tendency back to equilibrium ## Footnote Static stability refers to how an aircraft reacts immediately after a disturbance.
30
What is Dynamic stability?
Overall tendency after disturbance ## Footnote Dynamic stability considers how the aircraft behaves over time after a disturbance.
31
What does Longitudinal stability refer to?
Quality of pitch stability ## Footnote It assesses how well the aircraft maintains its pitch attitude.
32
What is Lateral stability?
Stability of roll ## Footnote Lateral stability ensures the aircraft maintains its roll attitude during flight.
33
What does Directional stability refer to?
Yaw stability ## Footnote It involves how well the aircraft maintains its directional path during flight.
34
What are the two components of lift in a turn?
* Vertical (upward) * Horizontal (inward) ## Footnote Understanding these components is essential for managing aircraft performance during turns.
35
What is a Coordinated turn?
Left turn, left rudder ## Footnote A coordinated turn maintains balanced flight and prevents skidding.
36
What is a Slipping turn?
Left turn, right rudder ## Footnote This type of turn can lead to a loss of control and should be avoided.
37
What is a Skidding turn?
Left turn, excessive left rudder (avoid) ## Footnote Skidding turns can cause adverse yaw and loss of control.
38
In a turn, what must be increased to equalize total lift and total weight?
Angle of Attack (AoA) ## Footnote Adjusting AoA is crucial for maintaining lift during turns.
39
What occurs during a climb when lift is initially greater than weight?
Aircraft will balance and airspeed decreases ## Footnote This indicates a transition from a climb to a stable flight condition.
40
What causes stalls in aircraft?
Exceeding critical AoA ## Footnote Stalls result in significant loss of lift, starting at the wing root and spreading to the wing tips.
41
What is the result of a stall combined with yaw?
Spin, uncoordinated stall ## Footnote This situation can lead to a dangerous loss of control.
42
What condition is necessary for recovery from a stall to be achieved?
Being within CG envelope ## Footnote Center of Gravity (CG) envelope is crucial for recovery.
43
What does the coefficient of lift (CL) describe?
Lift depending on atmospheric variables ## Footnote CL is a key factor in understanding lift performance.
44
What is CLMax?
Maximum peak of CL at critical AoA ## Footnote This is the highest lift coefficient before stall occurs.
45
What is the recovery procedure for a spin?
Full opposite rudder, elevator forward, aileron level, power idle ## Footnote These steps help regain control of the aircraft during a spin.
46
What is torque reaction in relation to propeller forces?
Opposite force trying to go opposite direction of propeller spin ## Footnote This creates a left turning tendency in the aircraft.
47
What is the corkscrew effect?
Spiraling slipstream around the plane causing left turn tendency ## Footnote This effect is due to the rotation of the propeller.
48
What does gyroscopic action refer to?
Turning of a gyro in response to a deflective force, felt 90 degrees later ## Footnote This can create either left or right turning tendencies.
49
What is P-factor in aviation?
Ascending blade is thinner than descending blade ## Footnote This phenomenon also contributes to the left turning tendency of the aircraft.
50
What is the load factor in aviation?
Amount of force of the aircraft’s structure, measured in G’s
51
What is the limit load factor?
Highest load factor in normal operation, specified by category (normal, utility, acrobatic)
52
What causes the load factor to increase significantly?
Centrifugal force and weight; increases significantly after 60 degrees of bank
53
What happens if an aircraft is flying below maneuvering speed?
Aircraft will stall before it breaks
54
What is the reference datum in aviation?
Invisible vertical plane from which weight arms are measured
55
How are arms measured in relation to the center of gravity (CG)?
Arms forward of CG are negative, behind are positive
56
Who is responsible for weight and balance in aviation?
Pilot in command (PIC)
57
What constitutes standard empty weight?
Airframe + engine + unusable oil and fuel
58
What is the basic empty weight of an aircraft?
Standard empty weight + flight instruments
59
Define payload in aviation.
Occupants + baggage
60
What is useful load?
Pilots + passengers + baggage + usable oil/fuel
61
Fill in the blank: Zero fuel weight = Useful load - _______
Fuel
62
What does fuel load refer to?
Usable fuel