Aerodynamics Flashcards

(84 cards)

1
Q

Minimum speed for T/O is about ____ above power-off stall speed

A

20%

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

Bad for T/O performance:

A

High, hot, heavy, humid

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

Max rate of climb (Definition) (and T-6)

A

Gaining the most altitude in a given amount of time, 140 KIAS

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

Max angle of climb (Definition)

A

The most altitude for distance travelled

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

How does altitude affect cruise?

A

Decrease in temperature = turbine engine more efficient = higher range & endurance because of less fuel

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

Does wind affect maximum endurance?

A

No

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

How does head and tail wind affect max range?

A

Head = decreased, tail = increased

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

Best glide speed (Definition)

A

The maximum range in a power-off glide

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

Where does best glide speed occur?

A

At L/D MAX, T-6 clean ≈ 125 KIAS

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

What is P-factor?

A

The yawing moment caused by one propeller blade creating more thrust than its opposing blade, if the free airstream relative wind is above the thrust line

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

Where is P-factor noticeable?

A

High power setting, thrust axis displaced from the relative wind

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

What causes the aircraft to accelerate until thrust equals drag?

A

Excess thrust (Newton’s 2nd law)

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

Aerodynamic centre is also known as?

A

Center of lift

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

Maxium endurance occurs at ____

A

bottom of the power curve

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

Maxium range occurs at ____

A

L/D max

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

In a spin, which wing will have the higher AOA?

A

inside wing

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

What’s the difference between erect and inverted spin?

A

Positive og negative G

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

Post-stall gyration (Definition)

A

Aerodynamic forces during a stall that result in movement around the pitch, roll, and yaw axes

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

Autorotation (Definition)

A

Combination of roll and yaw that propagates itself and progressively gets worse due to asymmetrically stalled wings

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

Conservation of angular momentum

A

CG and centre of lift come closer together

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

How does anti-spin rudder aid in recovery?

A

Slows rotation and decreases AOA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Spin to which side has the lower pitch, slower with more oscillation, and increased rotation rate due to gyroscopic precession?

A

right side

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

What is progressive spin?

A

Caused by maintaining full up elevator while holding anti-spin rudder, until rotation stops and then turns the other way

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

On a graph, where does boundary layer separation start to occur?

A

Where the coefficient of lift starts to bend

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Does a heavy aircraft have a higher or lower stall speed?
Higher
26
With IAS being the same, does stall speed increase or decrease with altitude?
Increase
27
When are the strongest vortices created?
Heavy + clean + slow
28
How does AOA affect vortices?
Higher AOA = bigger vortices, because greater lift
29
What are the four types that can cause yaw because of the propeller?
Gyroscopic processing, torque effect, p-factor, prop wash
30
Increasing performance wind shear
Lift and climb increases
31
Decreasing performance wind shear
Lift and climb decreases
32
Wind shear is caused by \_\_\_\_\_\_
low level jet streams, wind funneling, land-sea breezes, fonts, thunderstorms
33
What wind shear alert systems exists?
NEXRAD Doppler radars, Low-Level Wind Shear Alert Systems (LLWS), and PIREP
34
Wind shear T/O procedures
Longest suitable runway, T/O flaps but delay rotation by the amount of predicted shear (up to 10 knots), rotate to normal climb attitude and maintain
35
Wind shear landing procedures
Add up to 10 knots to speed (keeping in my the increased landing roll), resist temptation to make large power reductions, establish pitch, trim, and power settings by 1000' AGL
36
Order of loss of conrols
1. aileron 2. elevator 3. rudder
37
Boundary layer separation (Definition)
Point in the streamline where airflow no longer adheres to the airfoil
38
Moment (Definition)
Force applied at a distance from a pivot point (a lever)
39
Work (Definition)
Force \* distance
40
Power (Definition)
Work / time or Force \* velocity
41
Total energy (Definition)
Full measure of a body's capacity to do work
42
Potential energy (Definition)
Ability to do work based on position
43
Kinetic energy (Definition)
Ability to do work based on motion
44
Temperature (Definition)
Measure of the average kinetic energy of air particles
45
True altitude is also called \_\_\_\_
MSL
46
Pressure altitude is true altitude corrected for \_\_\_\_\_\_\_
atmospheric pressure
47
Density altitude is pressure altitude corrected for \_\_\_\_
temperature
48
Chordline (Definition)
an _infinitely_ long line passing through the leading and trailing edges of an airfoil
49
Flight path (Definition)
Path of CG through the air mass. Always opposite to the relative wind
50
Relative wind (Definition)
always opposite to the flight path
51
Pitch attitude (Definition)
Angle between the longitudinal axis and the horizon
52
AOA (Definition)
Angle between the chord line and the relative wind
53
What does CG affect?
Pitch and stability
54
Aerodynamic center placement \_\_\_\_
normally aft of CG. (Relates the 4 forces)
55
Aerodynamic force (Definition)
Force that results from pressure and friction distribution over an airfoil
56
What has the greatest affect on lift?
velocity
57
How can the pilot change the cL?
AOA or flaps
58
Total drag decreases until _____ then increases
L/DMAX
59
Form drag (Definition)
Separation of airflow; function of size and shape of airfoil. Caused by a difference between leading edge Ps and trailing edge Ps (kom endelig med en bedre forklaring)
60
Friction drag (Definition)
Turbulent airflow in the boundary layer
61
Interference drag (Definition)
mixing airstreams (fuselage and wing)
62
Minimum total drag occurs at \_\_\_\_\_
L/DMAX
63
Thrust required (Definition)
Equals total drag in equilibrium
64
Thrust available (Definition)
Thrust produced under a specific velocity, density and PCL setting
65
Thrust excess (Definition)
Difference between thrust available and thrust required. In a propeller aircraft, max thrust excess occurs below L/DMAX
66
Power required (Definition)
Power need to produce required thrust. In a propeller aircraft, minimum power required occurs below L/DMAX
67
Power available (Definition)
Power actually produced by the airplane's engine at a given PCL setting, velocity, and density
68
Power excess (Definition)
Difference between power available and power required. When available a/c will either climb and/or accelerate. Max excess occurs at L/DMAX
69
With an increase in altitude _____ is required to increase, but _____ remains constant (which one is power and which is thrust)
1: Power, 2: thrust
70
Prop hp vs shaft hp
Prop = thrust hp Shaft = engine output
71
Prop efficiency
Thrust hp divided by shaft hp
72
Critical Mach (Definition)
Mach number where first evidence of local supersonic flow occurs
73
Region of Reverse Command (Definition)
Area on the PR curve, left of min. power required, where a decrease in velocity requires an increase in power required
74
Slipstream Swirl (Definition)
Prop wash swirls clockwise around fuselage striking tail on the left side causeing left yaw
75
Torque factor (Definition)
Roll opposite the direction of propeller rotation
76
Gyroscopic precession (Definition)
Force progresses 90° in the direction of prop rotation. Affects variance in left and right spin
77
To maintain level flight during a 60° bank angle turn will require \_\_\_\_
2 G + thrust
78
Is a heavy/larger or a smaller/light plane hardest to meaneuvre, and why?
Heavy/larger, because it's more stable
79
\_\_\_\_\_\_\_\_ is the greatest positive contributor
Vertical stabilizer
80
Cross coupling
Roll causes adverse yaw and adverse yaw causes roll
81
Proverse roll (Definition)
Roll in the same direction as yaw
82
Geometric twist (Definition)
Reduction in angle of incidence from wing root to wing tip
83
Aerodynamic twist (Definition)
Reduction in camber from wing root to wing tip
84
Accelerated spin (Definition)
Spinning with the stick other than full aft