Aero Flashcards
(154 cards)
1
Q
What is Force?
A
Push or Pull exerted on a body (mass x acceleration)
2
Q
What is Mass
A
Quantity of Molecular Material
3
Q
What is volume?
A
Amount of space occupied
4
Q
What is density?
A
Mass/volume (mass per unit of volume)
5
Q
What is moment?
A
Force applied a distance from a pivot point (fulcrum)
6
Q
What is weight?
A
Force on a mass toward the Earth (G)
7
Q
Kinetic Energy
A
Energy of Motion (KE = (1/2)MV^2
8
Q
What happens to air density and temperature as altitude increases?
A
Both decrease
9
Q
What atmospheric properties affect pressure?
A
Density and Temperature
10
Q
What is total pressure
A
Static + dynamic pressure (Pt = Ps + Pd)
11
Q
What is true altitude?
A
actual height above MSL
12
Q
What is pressure altitude
A
Height above a standard datum plane (29.92 inHg)
13
Q
What is density altitude
A
Pressure altitude corrected for temperature (Index for gauging engine performance, not used as actual height reference)
14
Q
What is Indicated Airpseed (IAS)
A
Airspeed read from airspeed indicator
15
Q
What is calibrated airspeed (CAS)
A
IAS corrected for instrument error
16
Q
What is equivalent airspeed?
A
CAS corrected for compressibility (significant near the speed of sound)
17
Q
What is True Airspeed (TAS)?
A
Velocity through the air mass
18
Q
What is groundspeed
A
TAS corrected for winds
19
Q
What is Mach Number?
A
TAS/Speed of Sound
20
Q
What is critical mach number?
A
Speed where there is the first evidence of local supersonic flow
21
Q
What happens to TAS and Mach Number in a constant IAS Climb?
A
Increases (TAS- approximately 3 knots/1000 feet
22
Q
What are the three airplane axes?
A
Longitudinal, Lateral, Vertical
23
Q
What are the motions about axes?
A
Roll, Pitch, Yaw
24
Q
What is adverse Yaw?
A
Tendency for the aircraft to yaw opposite the direction of roll
25
Aileron corresponds to which axis?
Roll (Longitudinal)
26
Elevator corresponds to which axis?
Pitch (Lateral)
27
Rudder corresponds to which axis?
Yaw (Vertical)
28
What is Wingspan?
Length wingtip to wingtip
29
What is chordline
Infinite line through leading and trailing edges
30
What is chord
Width of wing, length from leading edgge to trailing edge
31
What is average chord
average of all chords
32
What is wing area
Wingspan x average chord
33
What is wing loading?
Weight/area
34
what is aspect ratio?
wingspan/average chord
35
What is angle of Incidnence?
Angle between chordline and longitudinal axis
36
What is dihedral angle?
Upward slope of wing from root to tip
37
What is relative wind?
Airflow experienced by aircraft or airfoil
38
what is Angle of Attack?
Angle between relative wind and chordline
39
What is the Mean Camber Line (MCL)?
Line halfway between airfoil upper and lower surfaces
40
What is camber?
Distance between the MCL and Chordline
41
What is Positive Camber?
When the MCL is above the chordline. Produces lift at 0 degrees AOA
42
What is the Aerodynamic Center?
Point on chordline where changes in aerodynamic forces take place (AKA the center of lift)
43
What is Spanwise Flow?
Flow parallel to the leading edge of the wing
44
What is chordwise flow?
Flow perpendicular to the airfoil
45
How are lift, weight, thrust, and drag related in level unaccelerated flight?
opposing aerodynamic forces are balanced (equal)
46
How are lift, weight, thrust, and drag related during the takeoff roll?
Weight is greater than lift, thrust is greater than drag
47
What is the center of gravity (CG)?
Point where weight is concentrated
48
What are the results of the CG being too far aft?
Tail Heavy
49
What are the results of the CG being too far forward?
Nose Heavy
50
Changing which factor in the lift equation will affect lift the most?
Velocity
51
How does a pilot change lift?
Primarily: AOA and Velocity
Secondarily: Adjusting Camber (changing shape of the wing)
52
What are the two parts of aerodynamic force due to airflow over the wing?
Lift and Induced Drag
53
What is total drag
Parasite drag + Induced Drag
54
What happens to parasite drag and induced drag as velocity increases?
Parasite drag increases
Induced drag decreases
55
What are the three types of parasite drag?
1. Form
2.Friction
3. Interference
56
Which parasite drag is the difference between static pressures of the leading and trailing edges?
Form
57
Which parasite drag is turbulent flow in the boudnary layer?
Friction
58
Which parasite drag is due to mixing airflows between components?
Interference
59
Describe the effects on lift and drag caused by lowering the flaps to Takeoff (TO)?
Big increase in lift, little increase in drag
60
Describe the effects on lift and drag caused by lowering the flaps to Landing (LDG)?
Little increase in lift, big increase in drag
61
What drag increases as Gs increase?
Induced
62
What is L/Dmax?
Lowest point on the total drag curve
Parasite = induced
Best glide speed
Most efficient AOA
63
What effect does lower the gear have on drag?
Parasite drag increases
64
At what velocites is induced drag the greatest?
Slower Speeds
65
If weight increases, how is equilbrium flight maintained?
AOA or velocity must increase
66
What is thrust horsepower?
Thrust: propeller output
67
What is shaft horsepower?
Engine Output
68
What factors affect thrust available?
PCL position, Altitude, Airspeed
69
Due to prop efficiencies, how does Pa change with velocity?
Pa decreases
70
What is thrust required?
Thrust needed to overcome drag (TR)
71
What is power required?
Power needed to produce Thrust Required
72
What is Excess Thrust?
Difference between TA and TR - TA > TR
73
What is Excess Power?
PA > PR, Excess results in climb or acceleration
74
What is the relationship between velocity, TR, and PR
TR decreases to L/Dmax then increases, PR decreases to an airpspeed below L/Dmax then increases
75
What is the result of PA being greater than PR?
Accelerate or climb
76
What effect does a change in configuration have on TA and TR?
TA is unaffected, Gear down requires increased TR
77
What effect does a change in configuration have on PA and PR?
PA is unaffected
Gear down requires increased TR
78
What factors increase takeoff or landing roll?
Increased weight
Higher altitude
increased temp
decreased headwind
increased tailwind
79
Changing which factor has the greatest effect? (on performance)
weight
80
Define: Max Rate of climb
(Vy) - airspeed to get the most alt in the least amount of time
81
Define: max angle of climb
(Vx) - airspeed to get the most alt in the least distance
82
Define: best glide speed
(125 Kias) - max power off range
83
Define: max range
max distance for a set amount of fuel
84
Define: max endurance
max time airborne for a set amount of fuel
85
What is long range cruise? (LRC)
airspeed above max range that gives you 99% of max range
86
what factors decrease both max range and max endurance?
increased weight
lower alt
"dirty" config
higher temps
87
what factors decrease glide range?
"dirty" config
lower alt
increased headwind
decreased tailwind
unfeathered prop
88
what factor changes groundspeed, but has no effect on TAS
headwind or tailwind
89
where does max range for a propeller aircraft occur
L/Dmax
(on Pr curve)
90
Where is the region of reverse command?
Left of max endurance on the power required curve, left of L/Dmax on thrust curve
91
What is the region of reverse command?
Part of the PR curve where decreased airspeed requires increased power
(for straight/level flight)
92
What is critical Mach?
first evidence of local supersonic flow occurs
93
What is Slipstream Swirl?
left yaw, resulting from propeller airflow past the rudder
94
What is the correction for Slipstream Swirl?
right rudder
95
What causes P-factor?
Ascending and descending blades producing different amounts of thrust based on different
AOAs of the blades
96
What is the correction for P-factor?
Opposite rudder
97
What is propeller torque?
Roll the opposite direction of the propeller, correct with right rudder
98
contrast a slip and a skid
Slip: opposite or insufficient rudder in direction of turn
(needle ball same side)
Skid: too much rudder in direction of turn
(needle ball opposite sides)
99
Why must back pressure be added in a turn?
Increase total lift because the vertical component of lift must equal weight
100
Why must power be increased during a turn?
Increased AOA means increased induced drag - requiring more power
101
What is turn rate?
Degrees of heading change
(degrees/second)
102
What two things determine turn rate and radius?
bank angle
velocity
103
Define: limit load factor
Max load no damage
104
Define: ultimate load factor
Max load without failure
105
Define: maneuvering speed
Max speed where abrupt control inputs will not cause damage
106
Define: asymmetric Gs
Pulling Gs with aileron or rudder deflections
107
What are the T-6 asymmetric load limits?
-1.0 to 4.7 Gs
108
What are the T-6 symmetric load limits?
-3.5 to 7.0 Gs
109
How will an increase in bank angle for a level turn change the required G's?
It will increase the required Gs
(60 deg of bank = 2Gs)
110
What is dynamic stability?
Measure of displacement over time after disturbance
111
Describe a PIO
Pilot Induced Oscillations: Longitudinal stability of aircraft and pilot working to
counteract movement around the lateral axis
112
Why do we have a vertical stabilizer?
To increase yaw or directional stability
113
Contrast stability and maneuverability
stable - less maneuverable
more manueverable - less stable
114
As CG moves aft what happens to stability?
Less stable/unstable
115
Describe Boundary Layer Separation
Airflow no longer adheres to airfoil
116
Why does Boundary Layer Separation occur
Decreasing ratio of kinetic energy to the adverse pressure gradient
117
What is a stall
An increase in AOA produces a decrease in CL (Lift)
118
Contrast airspeed and roll tendency between a power-on stall and power-off stall
Power ON: lower stall speed, roll to the left
Power
OFF: higher stall speed, roll right
119
What factors change stall airspeed
Weight, Gs, Bank angle, altitude
120
How is the stall speed changed by a steeper bank angle
Increases
121
When does the stall occur?
CL max, exceeding critical angle of attack
122
When does the stall recover
When AOA is below stall AOA
123
In what order are the flight controls lost in a stall
Aileron, Elevator, Rudder
124
In a stall recovery which is the most effective
Rudder
125
In a stall recovery which is the least effective
Aileron
126
Where does the stall occur on the CL curve
At the top of the curve - CLmax
127
What is the T6 stall AOA
18 units
128
When the stick is full aft, what happens to the rotation rate of a spinning T6
Slows down
129
What is the primary difference between an inverted vs. erect spin
Inverted: Negative G stall - attitude does not matter
130
Which flight control provides the greatest anti spin force
Opposite rudder
131
What factors effect wingtip vortex strength
Weight
Speed
Configuration
132
What generates wake turbulence
Any aircraft producing lift
133
Which direction do wingtip vortices rotated (as viewed from behind)
Left: Clockwise
Right: Counterclockwise
Both flow inwards
134
Describe the descent characteristics of wingtip vortices
Descend 400 to 500 fpm
Level off 800 to 900 feet below
135
Which aircraft produce the strongest vortices
Heavy
Clean
Slow
136
When do the vortices stop
Upon nose-wheel touchdown
137
What is min spacing taking off behind a large or heavy aircraft
2 mins
138
What is min spacing when landing behind a large or heavy aircraft
Large - 2
Heavy - 3
139
What is your flight path and touchdown point behind a landing heavy aircraft
Above flight path and touchdown beyond where the nose wheel touched
140
What is wind shear
Sudden change in windspeed or direction
141
Describe a decreasing performance wind shear
Lift and climb decrease
Airspeed, pitch and VSI decrease
142
Describe an increasing performance wind shear
Lift and climb increase
Airspeed, pitch and VSI increase
143
What is max airspeed adjustment
10 knots
144
With a reported 15 knot loss, what adjustments will you make
Flaps TO
Add 10 knots to airspeed
Watch for tendency to land long
145
What provides stall warning in the T6
Stick shaker
AOA Gauge
Aerodynamic forces on empennage
146
What is function of the leading edge slats
Control boundary layer separation (increases surface area)
147
What two factors are necessary for a spin
Stall and Yaw
148
Contrast lift and drag between a stalled aircraft and a spinning aircraft
Stall: balanced lift and drag on each wing
Spin: yaw causes asymmetric lift and drag
149
Describe asymmetric wing stall
Unequal lift and drag that generate forces to sustain the aircraft in a spin
150
Describe an erect accelerated spin
Control stick other than full aft
151
Describe a progressive spin
Holding the stick aft while applying opposite rudder
152
Why is a left spin different from a right spin
Gyroscopic effect of the propeller
153
What is the difference of right and left spin?
Right: Lower pitch, Faster rotation, Slower to stabilize
154
When the stick is full aft, what happens to the pitch of a spinning T6
Spin flattens
