SIFT Flashcards
(404 cards)
1
Q
The ______ position relative to the horizon determines the helicopter’s travel and attitude.
A
Cyclic.
2
Q
What increases when you bank a helicopter while maintaining a constant altitude? (Especially in banks greater than 30 degrees?)
A
Weight (load factor, G factor).
3
Q
What is hypoxia? What are it’s main causes during flying?
A
Lack of sufficient oxygen.
Flying above 10k ft in a non pressurized aircraft without supplemental oxygen, rapid decompression during flight, pressurization system malfunction, oxygen system malfunction.
4
Q
In which direction is lift generated?
A
Perpendicular to the relative wind/tip-path of the plane of main rotor.
5
Q
With the antitorque pedals in the neutral position, the tail rotor has a medium ________ pitch angle.
A
Positive.
6
Q
What are the differences between the traffic patterns of airplanes and helicopters?
A
Airplanes fly their traffic patterns at 1000ft AGL
Helicopters fly their traffic pattern at 500-1000ft AGL
Airplanes have a left turn traffic pattern
Helicopters have a right turn traffic pattern
7
Q
What are the main types of rotor systems?
A
Rigid, Semi-rigid, Fully articulated.
8
Q
How much the helicopter banks is based on _____
How fast the helicopter banks is based on ________
A
How long the cyclic pressure is applied
How hard the cyclic pressure is applied
9
Q
The component of lift that is acting in a rearward direction?
A
Induced drag.
10
Q
Generally input lead is ____ % of climb rate?
A
10%
For example if you’re climbing at a rate of 500fpm, you should lead the level off by 50ft
11
Q
Without a tail rotor, which direction would a helicopter yaw?
A
Opposite its rotation.
12
Q
What pitot-static instrument uses both pitot and static air pressure.
A
Airspeed indicator
13
Q
To enter a turn from straight-and-level
flight what control is used? What control should only be used for a specific reason? What is that control and what is the reason?
A
The cyclic should be used to enter into a turn from straight-and-level flight. The pedals do not need to be used, and shouldn’t be used unless to compensate for torque and correct trim around the vertical axis.
14
Q
What is the major form of drag at higher airspeeds?
A
Parasitic drag
15
Q
Helicopters usually hover ___ side low
due to the _____
A
left, tail rotor thrust being counteracted by the main
rotor tilt.
16
Q
What is current measured in?
A
Amps.
17
Q
Where is the horizontal reference datum located?
A
E: The horizontal reference datum is an imaginary vertical plane or point, arbitrarily fixed somewhere along the longitudinal axis of the helicopter, from which all horizontal distances are measured for weight and balance purposes. There is no fixed rule for its location. It is established by the helicopter manufacturer.
18
Q
When should preflight inspections be conducted? Why?
A
As early as possible in the flight planning sequence, preferably during the day.
19
Q
Why must the collective and cyclic be used in unison during takeoff?
A
Because as the helicopter accelerates, it must also climb to stay within safe velocity-altitude parameters.
20
Q
The driven region is ________ the blade tips and normally __ percent of the radius:
A. nearest, 30
B. furthest from, 30
C. mid-span from, 50
D. nearest, 50
A
A
21
Q
What is the solidity ratio?
A
It is the ratio of the total rotor blade area, which is the combined area of all the main rotor blades, to the total rotor disk area.
22
Q
Empennage refers to what?
A
The tail section
23
Q
What part compensates for gyroscopic precession?
A
Pitch horn.
24
Q
How many fundamental forces are there? Name them.
A
- Gravity, nuclear, electromagnetic, and weak
25
Which of these is one of the three types of drag that constitute total drag?
a. Inversion
b. Paradox
c. Subduction
d. Accelerated
e. Parasite
E: Parasite. The force that resists the movement of a helicopter through the air and is produced when lift is developed is called drag. Drag must be overcome by the engine to turn the rotor. Drag always acts parallel to the relative wind. Total drag is composed of three types of drag: profile, induced, and parasite.
26
To maintain airspeed in a 2G/60° turn, rotor thrust/engine power must increase by ____ percent.
D: 100.
27
What is visual scanning and how is it conducted?
the consistent scan to avoid hazards, known or unknown to a pilot.
It's conducted by using a series of short, regularly spaced eye movements in 10 degree sectors.
28
What subatomic particles are found in the nucleus?
Protons and neutrons
29
What direction does induced drag push?
Opposite of lift
30
Why do wheeled helicopters perform better than skidded ones in a surface takeoff?
Because the maneuver involves sliding across the surface as speed increases.
31
What are the Army designations for the following aircraft:
Apache
Blackhawk
Chinook
Kiowa
Lakota
AH-64
UH-60
CH-47
OH-58
UH-72
32
In what conditions is a helicopter most vulnerable to mast bumping?
Low G conditions
33
What happens if a pilot pushes the cyclic in one direction and then releases it?
A. The helicopter will stop moving immediately.
B. The helicopter will continue moving in that direction at a similar velocity.
C. The helicopter will accelerate until drag stops it.
D. The helicopter will reverse direction automatically.
B
34
What are the 3 types of turns?
Shallow Turn - less than 20 degrees (hold to maintain), Medium Turn - 20 - 45 degrees (holds itself), Steep Turn - 45 degrees (hold against).
35
Which is the only form of drag to decrease as airspeed increases?
Induced drag
36
The tendency of a rotary-wing aircraft to drift laterally due to tail rotor thrust is called_____
Translating tendency.
37
What is the formula used to calculate the mechanical advantage of an inclined plane?
length/height
38
On a turn coordinator, where would the ball be in slipping, skidding, and standard turns?
Slipping - Direction of the turn
Skidding - Opposite direction of turn
Standard - Middle
39
What are non fundamental forces?
Forces that are derived from the four foundational forces.
40
What conditions can make it hazardous to operate the helicopter at or near its maximum gross weight?
High altitude
## Footnote
Factors that can make it unsafe to take off operating at maximum gross weight include high altitude, high temperature, and high humidity conditions.
41
What are the 2 components of wind velocity?
Wind velocity is the sum of aircraft speed and rotational velocity.
42
In powered flight (hovering, vertical, forward, sideward,
or rearward), the total lift and thrust forces of a rotor are
_______ to the rotor disk.
Perpendicular
43
Which of the following statements is FALSE regarding most helicopters?
a. During left turns, torque increases.
b. During right turns, torque decreases.
c. During application of aft cyclic, torque decreases and rotor speed increases.
d. During application of forward cyclic, torque increases and rotor speed decreases.
e. None of these are false
None of these are false
## Footnote
The other answers are all true in most helicopters.
44
Which Army helicopter is the lightest (i.e., has the lowest empty weight)?
The OH-58A Kiowa
## Footnote
The OH-58A Kiowa has an empty weight of 1,583 pounds.
45
Mach 1 is x km/h?
1234
46
The __________ position relative to the horizon determines the helicopter's travel and attitude.
B: The cyclic position relative to the horizon determines the helicopter's travel and attitude.
47
What is Operating Empty Weight?
The MEW plus the weight of crew, fluids, unusable fuel, and the equipment required for flight. Doesn't include baggage, passengers, or usable fuel.
48
Which attack helicopter features four hardpoints mounted on stub-wing pylons?
The AH-64 Apache
## Footnote
The AH-64 Apache usually carries a combination of AGM-114 Hellfire missiles and Hydra 70 rocket pods.
49
An exterior angle of a triangle is equal to what?
the sum of its two interior opposite angles
50
When training for a rapid deceleration, the entry speed should be approximately how many knots in most helicopters?
D: 45 knots. Training maneuvers for rapid deceleration should always be done into the wind.
51
What is the formula used to calculate the mechanical advantage of a wheel and axle?
Radius of wheel/radius of axle
52
What are the 3 types of marked runways?
Visual runway markings
Nonprecision instrument runway
Precision instrument runway
53
How is vertical trim indicated on a helicopter?
By a yaw string (also referred to as a slip string) in the center or a centered ball on a turn and slip indicator.
54
When might a forward center of gravity NOT be obvious?
Hovering in a strong headwind
## Footnote
A forward CG is easily recognized when coming to a hover following a vertical takeoff but not as obvious when hovering in a strong wind.
55
What is the typical voltage and frequency of electricity in american households?
120V 60Hz
56
How many feet in a mile?
5280
Five tomatoes
57
At speeds above translational lift, what control is used to turn?
Cyclic.
58
What tool measures electical resistance?
Ohmmeter
59
What is the equation used to find the final velocity of an object dropped at a certain height?
v² = u² + 2as
v = final velocity
u = initial velocity
a = acceleration due to gravity
s = distance dropped
60
What are Runway Edge Lights? What color are they?
Lights which mark the edges of a runway. They are white in color (yellow along the last 2000ft of instrument runways)
61
What is payload?
The term used for passengers, baggage, and cargo of an aircraft
62
The ________ is a mechanical connection between the collective lever and the engine throttle.
Correlator.
63
From a physics perspective, the ______ force is deemed to act through a helicopter's __________:
A. lift, center of motion
B. total weight, center of gravity
C. induced drag, longitudinal axis
D. total mass, center of motion
B
64
Lowering the collective _____ torque
Decreases
65
What is the normal air taxi altitude limit?
100 ft AGL
66
The phenomenon of a helicopter sinking into its own downwash is called:
A. L/Wmin (minimum lift-to-weight ratio).
B. An airfoil stall.
C. Vortex torque state.
D. Settling with power.
D
67
Do aircrafts perform better in warmer or colder weather?
Colder.
68
What is load factor?
Load factor is the ratio of the total load supported by the aircraft's airfoil to the actual weight of the airplane and its contents.
69
The column of air passing through the rotor blades is known as _____________.
Induced flow or downwash.
70
What instrument displays altitude of an aircraft?
Altimeter.
71
What is the primary means for compensating for dissymmetry of lift?
Blade flapping.
Cyclic feathering is secondary.
72
What is Maximum Landing Weight?
An aircraft's weight limit for landing. Exceeding this weight increases stress on the landing gear and may increase distance needed for landing.
73
When is an aircraft considered to be IGE?
When it's within one wingspan to the ground.
74
What is an electrical circuit?
A path or loop that electricity can follow.
75
In a series circuit, when there is a resistor, which of the following happens:
A. Current is decreased
B. Current remains the same
C. Voltage remains the same
B.
In a series circuit, current is the same everywhere.
76
What is a yaw string or slip string?
A tool used to indicate slip or skid during flight. It is simply a string attached to the nose or canopy of an aircraft so that it is visible to the pilot during flight. . The string measures sideslip and offers
a visual cue to the pilot in order to make yaw corrections.
77
What item was developed to reduce compass reading errors?
A vertical card compass
78
What must a pilot be cautious of when slowing down?
Avoiding the shaded area of the height-velocity diagram, which represents unsafe flight conditions.
79
the total lift and thrust
vectoring is controlled by what?
what is vectoring?
the cyclic
vectoring is controlling the direction of a force
80
What kind of hovering turn requires the most left pedal pressure in turn?
A hovering turn with right cyclic into the wind.
81
What is angular momentum?
The moment of inertia (mass times the distance from the rotational center squared) multiplied by the speed of rotation.
82
How does a retreating blade stall occur and how does this affect the helicopter?
Retreating blade stall occurs when the never-exceed velocity of a helicopter is exceeded. At this velocity, the AOA and relative wind speed of the retreating blade is too great.
It is evidenced by a nose-high attitude, vibration, and a tendency to roll left.
83
Torque & rpm _____ for aft/forward cyclic
Aft - Torque decrease, RPM increase
Forward - Torque increase, RPM decrease
84
What drag develops from the frictional resistance of the blades passing through the air?
Profile drag.
85
What is the outer shell of an atom called?
Valence shell
86
What is the Magnus Effect?
Lift force created by spin of rotor blades.
87
Define class G airspace, it's visual requirements at day and night, it's altitudes.
Class G is uncontrolled airspace from 1200 ft to 10000 ft with a visual requirement of 1 mile during day and 3 miles at night. Above 10000 ft, a visual requirement of 5 miles exists, day or night.
88
What is a simple machine?
A machine that changes the magnitude or direction of an applied force, leading to mechanical advantage.
89
What is the main rotor hub?
Where all the components of a main rotor head are attached.
90
During an autorotation, how many points of equilibrium are on the blade? Where are they located?
2. One is between the driven and driving, the other between the stall and driving.
91
What are position lights?
Lights on an aircraft that help identify it.
92
Air pressure decreases _____ in. of mercury for each _____ ft. of altitude.
1, 1000.
93
What is crabbing?
When the nose of the aircraft is not aligned with the direction of movement
94
A positive and negative tail rotor pitch angle moves the tail in which direction?
Positive = Right, Negative = Left.
95
What is electricity?
The movement of electrons
96
How can skidding be corrected?
By increasing pedal pressure away from the turn or decreasing pedal pressure in the direction of the turn.
97
If a night preflight is necessary, a flashlight with
what color should be used to supplement
lighting?
White
98
What is a descent at minimum safe airspeed?
A nose-high controlled descent used to clear obstacles on short approach.
99
What is the Coriolis Effect also referred to as?
Law of conservation of angular momentum
100
What are the three regions of a rotor in autorotation?
Stall, Driving, Driven
101
What control is used to make a turn at a hover?
Pedals.
102
Walk me through the steps at 90 degree increments required to make a 360 degree turn from a hover while beginning in a weathervane position.
1. Apply forward cyclic to maintain position, apply left pedal
2. Apply right cyclic to maintain position, apply more left pedal to counteract crosswind
3. Apply aft cyclic to maintain position, apply right pedal
4. Apply left cyclic to maintain position, apply a bit more right pedal to slow down stronger left turn force from crosswind
103
What indicates that the helicopter is ready to lift off from the ground during a surface takeoff?
The helicopter becomes progressively lighter as it accelerates.
104
What is Maximum Ramp Weight?
An aircraft's weight limit to taxi or be towed on ground.
105
Torque _____ during left/right turns
Increases left
Decreases right
106
What is density altitude?
Pressure altitude corrected for non-standard temperature.
107
What type of helicopters should surface taxiing not be attempted with?
Skid type helicopters
108
Over what kind of surfaces is maximum ground effect achieved?
Smooth, hard surfaces.
109
The force created by air moving over an object (or moving
an object through the air) is called
Aerodynamic force
110
The steeper the bank is, AOA must be _____ in order to maintain altitude. This is accomplished by _____
increased, increased collective
111
What are the steps of a vertical takeoff to hover?
1. Ensure helicopter has neccessary clearance to take off
2. Make sure the area around the helicopter is free of any obstructions
3. Proceed to takeoff. With collective fully down, neutral cyclic, collective should be increased smoothly. Pedals should be applied to maintain heading, and the cyclic should be coordinated for a vertical ascent. As the aircraft leaves the ground, proper control response and aircraft center of gravity should be checked.
112
What does Bernoulli's principle state?
The pressure of a fluid decreases when the speed of the fluid increases.
113
What is considered a steep approach angle in degrees?
Approximately 13-15 degrees
## Footnote
An approach angle of approximately 13-15° is considered a steep approach.
114
The twin-engine, tandem rotor helicopter that came to prominence in the Vietnam War and is still in current use is the:
C: The CH-47 Chinook came to prominence in the Vietnam War and is still in current use.
115
During any given moment in flight, a helicopter's rotor system has a particular angular momentum. If a helicopter conducts a turn at 60 degrees bank, how would that affect the following:
RPMs
Coning angle?
To preserve angular moment, RPMs would increase as coning angle increases and rotor length decreases due to increased load.
116
Which Army helicopter has the highest maximum speed?
The CH-47 Chinook
## Footnote
The CH-47 Chinook has a maximum speed of 170 knots.
117
When 2 aircraft approach each other (not head on) at generally the same altitude, which aircraft has the right of way?
The aircraft on the right
118
How can one prevent confusing ground lights with horizon lights when flying at night?
By referencing flight instruments and getting a true horizon and attitude.
119
What is another name for the law of conservation of angular momentum?
The Coriolis effect
## Footnote
It states that the value of angular momentum of a rotating body does not change unless an external force is applied.
120
What percentage of engine power do tail rotors rob?
30%
121
What is All-Up Weight or Aircraft Gross Weight?
Total aircraft weight at any given moment of a flight.
122
What does a pitot tube measure?
Fluid velocity.
123
When performing a hovering turn on a windy day, at what point is weathervane most likely to cause problems?
When the helicopter's heading is in the wind
124
What is induced drag?
When, at the back of the wing, air flowing rapidly across the top meets air flowing slowly underneath, creating a vortex. Because AOA is higher at lower air speeds, induced drag decreases at higher air speeds and increases at lower.
125
Which anti-torque pedal increases pitch angle?
Left
126
What are pitot tubes and static ports?
Devices that extend outside the aircraft's structure to collect outside air and static pressure.
127
What are the movements along each of an aircraft's axes called?
Roll (Longitudinal), Yaw (Vertical), and Pitch (Lateral)
128
When should counter cyclic pressure be applied to stop the turn accurately?
Shortly before reaching the desired heading, to account for the time required to level out.
129
How quickly can a helicopter descend during VRS?
6000ft/min
130
Name some non foundational forces.
Friction, weight, buoyancy, tension.
131
Which anti-torque pedal requires more throttle?
Left
132
What is mechanical advantage?
The ratio of force that is output from a machine relative to the force input.
MA = Output/Input
133
What is blade coning?
The effect of centrifugal force pulling the rotating blades outwards and lift pulling them upwards. This makes the shape of the blades resemble that of a cone. The exaggeration of this varies based off the centrifugal force and lift force.
Higher RPMs = Straighter blades
More lift = Blades more curved upwards.
134
What power setting should be used during terminations to a hover?
100% of maximum
## Footnote
Normal helicopter landings usually require high power settings, with terminations to a hover requiring the highest power setting.
135
How many classes does the FAA divide airspace into? What are they?
Six.
A
B
C
D
E
G
136
What speed does the transverse effect usually occur?
10-20 kts.
137
When is a takeoff from the surface typically used instead of a takeoff from a hover?
When the helicopter lacks sufficient power to hover, usually due to excessive weight or high-density altitude.
138
A ________ is a sensing device that senses rotor and engine rpm and makes the necessary adjustments in order to keep rotor rpm constant.
Governor.
139
Why are the anti-torque pedals still needed in a banking turn?
To prevent slipping or skidding and maintain efficient flight.
140
What form of drag starts off as the most significant?
Induced drag
141
What is a newton?
A unit used to measure force. It is defined as the force required to accelerate a 1kg object 1m/s^2.
142
How is resistance measured?
In ohms. One ohm is amount of resistance that will allow one amp of current to flow if one volt of electrical pressure is placed on a conductor.
143
Why must the collective and throttle be reduced after a turn?
Because reducing the banking angle restores lift, and failing to adjust can cause the helicopter to climb.
144
What are the two main variables that affect drag?
Cross-sectional area and speed
145
How is class G airspace identified on sectional maps?
By a faded, thick blue line.
146
What is the best angle of climb?
The most altitude gained over a given amount of distance. Navigating obstacles usually requires this climb.
147
Which helicopter came to prominence in the Vietnam War and is still in current use?
The CH-47 Chinook
## Footnote
The CH-47 Chinook came to prominence in the Vietnam War and is still in current use.
148
If left uncorrected, greater lift produced by the advancing side of the rotor disk compared to the lift created by the disk's retreating side could make the helicopter ___________.
A. fly in a sideslip
B. vibrate excessively and come apart
C. torque clockwise
D. uncontrollable
D
149
What is the goal of straight and level flight in a helicopter?
To maintain a steady flightpath without unintended changes in altitude, velocity, or heading.
150
How do you prepare your eyes for night flight?
Give eyes 30 minutes to adjust to darkness. Avoid artificial light 30 mins prior to flying.
151
After establishing the proper bank angle in a turn, what should you do?
Return the cyclic position to neutral
152
What three conditions are necessary for a helicopter to be in danger of a dynamic rollover?
pivot point, a rolling moment, and a thrust
153
What are the two types of mechanical energy?
Kinetic and potential
154
At speeds above translational lift, what control is used to maintain longitudinal trim?
Pedals.
155
What are fundamental forces?
Forces that form the basis of all other forces
156
How does low air density affect an aircraft's performance?
Negatively.
157
Risk management is composed of which four risk elements?
Pilot, aircraft, environment, and external pressures
158
What is an Approach Light System?
Lights on a runway that assist a pilot in transitioning from a instrument flight to visual flight for landing.
159
What is the formula used to calculate the mechanical advantage of a lever?
length of effort arm/length of load arm
160
What is the sideward movement called during hovering flight in a single main rotor helicopter?
Translating tendency
## Footnote
This lateral (or sideward) movement is called translating tendency.
161
If a helicopter in straight and level flight drifts away from its intended path, what should the pilot do to correct its path?
Apply cyclic pressure in the direction of the desired path.
162
What is the relationship between parasite drag and velocity?
Parasite drag varies with the square of velocity. Therefore if airspeed is doubled, parasite drag increases fourfold.
163
Each gallon of reciprocating engine oil weighs _____ lbs.
C: Each gallon of reciprocating engine oil weighs 7.5 pounds.
164
What is electrical resistance?
Opposition to the flow of current
165
What is located on the left side of the pilot's seat?
Collective pitch control
## Footnote
The collective pitch control (or simply 'collective' or 'thrust lever') is located on the left side of the pilot's seat.
166
Which of the following is NOT one of the controls used by a helicopter pilot during flight?
a. Collective pitch
b. Torque pedals
c. Antitorque pedals
d. Cyclic pitch
e. Throttle
B: Torque pedals. There are three major controls in a helicopter that the pilot must use during flight: the collective pitch control, the cyclic pitch control, and the antitorque pedals or tail rotor control.
167
What controls roll, pitch, and yaw?
Ailerons, Elevators, Rudder
168
Below what height in feet AGL should the antitorque pedals be adjusted during a steep approach?
Below 100 feet AGL
## Footnote
The antitorque pedals should be adjusted to align the helicopter with the intended touchdown point.
169
In the formula for potential energy, what measurement is height in?
Meters
170
What is the major drag type at higher airspeeds?
Parasite drag.
171
How are amps defined?
One coulomb (basic unit of electrical charge) flowing past a given point in one second.
172
How are lever types defined in terms of location of fulcrum, load, and effort?
First class lever - fulcrum between load and effort (seesaw)
Second class lever - load between fulcrum and effort
(wheelbarrow)
Third class lever - effort between fulcrum and load
(tweezers)
173
In forward flight, at what positions does the blade meet the highest and lowest wind velocity?
3 o'clock and 9 o'clock
174
How does an altimeter work?
A capsule sealed with a starting air pressure is surrounded by a case of static air pressure that's fed by a port. The sealed capsule drives a needle. Based off the change in static pressure of air in the case surrounding the capsule, the capsule will expand or shrink, moving the needle as it does so.
175
In which direction does drag act?
Parallel to the wind.
176
What color are taxi way edge lights?
Blue
177
What is the standard turn rate?
3 degrees per second.
178
On helicopters with a counter-clockwise rotor system, what side of the helicopter is the tail rotor mounted on?
Left
179
What must be done whenever the collective is raised?
Increase throttle to maintain RPM and use anti-torque pedals to counteract increased torque.
180
What visual technique can a pilot to use to maintain line in directional flight?
Picking two reference points in front and staying in line with those.
181
This ratio provides a means to measure the potential for a rotor system to provide thrust and lift.
Solidity ratio.
182
What is the first goal when increasing the throttle and collective in a surface takeoff?
To make the helicopter light on its skids.
183
What do the following helicopter designations stand for?
A -
C -
H -
O -
T -
U -
A - Ground Attack
C - Transport
H - Search and Rescue, Medevac
O - Observation
T - Training
U - Utility
184
During an autorotation in forward flight, the rotor disk takes in ________ air and the driven, driving, and stall regions of each blade move ________ along its length (span), but only on the ________ side of the disk:
A. upward flowing, outboard, retreating.
B. downward flowing, inward, advancing.
C. upward flowing, inward, retreating.
D. ambient, outward, advancing.
A
185
What is the flight envelope?
The boundaries within which an aircraft can safely operate, including altitude, airspeed, AOA, and load factor.
186
During an autorotation, the drag of the transmission tends to yaw the nose to which direction?
The left, or in the same direction the main rotor is turning.
187
What should the pilot do as the helicopter becomes light enough to lift off during a surface takeoff?
Increase the collective to assist the takeoff and prepare to increase cyclic when the nose begins to rise due to transitional lift.
188
What is ohm's law?
V = IR
V - voltage
I - current
R - resistance
This shows the relationship between the three variables through a wire.
189
What is a freewheeling unit?
A clutch mechanism that allows the rotor to turn without engine power. This clutch mechanism is automatically engaged during engine fails to allow autorotation of the blades.
190
What is potential energy?
Energy that has the potential to be converted to kinetic energy. The formula for calculating potential energy is:
PE = mgh
191
What controls roll, pitch, and yaw?
Ailerons, Elevators, Rudder.
192
What is settling with power?
A condition where rotor efficiency is lost despite engine power being applied. Vortices develop not only at the tip as normal, but also along the blade. Also known as vortex ring state.
193
The analogic altimeter has 2 needles:
The longest one for the _____ of feet
The shortest one for the _____ of feet
hundreds
thousands
194
What is the primary use of OH-58 Kiowa helicopters?
Armed reconnaissance in support of ground troops
## Footnote
The primary use of OH-58 Kiowa helicopters is armed reconnaissance in support of ground troops.
195
What is a slipping turn?
What causes it?
When the tail of an aircraft moves toward the center of a turn.
It's caused by insufficient anti-torque/rudder input in the direction of the turn, or too much in the opposite direction of the turn.
196
In which direction hover is a higher than normal altitude preferred?
Rearward
197
What conditions must be checked before beginning a takeoff from hover?
Power, Balance, Flight controls, Fuel levels
198
can you add x^2 + x^3? why or why not? what about multiply?
No, you can't add them. In order to add two terms, they must be like terms—which means they must have the same variable raised to the same exponent.
Yes, you can multiply them.
199
What is the preferred method of descent?
Partial power descent.
200
What must a pilot do to stop the helicopter’s horizontal movement after using the cyclic to initiate drift?
A. Hold the cyclic in the direction of movement until the helicopter slows down.
B. Release the cyclic and allow drag to naturally stop the helicopter.
C. Apply the cyclic briefly in the opposite direction of movement.
D. Continuously push the cyclic forward until reaching the destination.
C
201
Where in an atom are electrons found?
Outside the nucleus
202
Archimedes principle
indicates that the upward force that is exerted on an object immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that is displaced by the object.
203
What is the difference between a vector and scalar quantity?
Vector quantities have both magnitude and direction.
Scalar only magnitude.
204
What are the three components of an electrical circuit?
A voltage source, a load, and a conductor.
205
How does collective input affect the sizes of the three rotor regions in the event of an autorotation? How does this affect the rotor in terms of rpm and acceleration force?
As collective is increased during an autorotation, the driving region is decreased and stall and driven regions increase. This lowers acceleration force and rotor rpm.
206
What is the purpose of a vertical fin or stabilizer?
To provide directional stability/heading control
207
What is weathervane?
The tendency of a helicopter to turn into the relative wind
208
What does the work-energy theorem state?
That the work done to an object will be converted to kinetic energy.
W = KE
209
How does a takeoff from the surface begin?
With the helicopter on the ground, collective and throttle at their lowest settings, and a cleared area serving as the runway.
210
What changes the angle of incidence differentially around the rotor system?
Cyclic feathering
## Footnote
Cyclic feathering changes the angle of incidence differentially around the rotor system. It creates a differential lift in the rotor system by changing the AOA differentially across the rotor system.
211
Which of the following has been the Army's primary training helicopter since 1993?
B: The Bell TH-67 has been the Army's primary training helicopter since 1993.
212
Tail rotor thrust is increased when this direction of pedal is used.
Left
213
For a helicopter fuselage to remain horizontal in hovering flight, with no cyclic pitch control needed except for wind correction, the Center of Gravity should be where?
Directly under the main rotor mast.
214
What are the axes of an aircraft?
Longitudinal, lateral, and vertical.
215
What is Maximum Takeoff Weight?
An aircraft's weight limit for takeoff. Exceeding this limit increases the power required for takeoff, lengthens the distance needed for lift off, and places excess stress on the aircraft.
216
How is electrical power calculated?
P = IV
P - Power
I - Current
V - Voltage
217
What equipment can be added to a skidded helicopter to assist in a takeoff from the surface?
Special "skid shoes" to reduce friction.
218
How much does air weigh?
14.7 psi.
219
What instrument should be used in case of an attitude indicator fail?
Turn coordinator
220
The solidity ratio is the:
C: The solidity ratio is the ratio of the total rotor blade area (the combined area of all the main rotor blades) to the total rotor disk area.
221
At what point does a takeoff from the surface become identical to a takeoff from a hover?
Once the helicopter lifts off and enters phase three of the hover takeoff process.
222
What is crabbing into the wind?
Making a coordinated turn into the wind to maintain the desired ground track.
223
How does the vertical speed indicator work?
Uses a diaphragm to compare the static pressure outside the aircraft to the static pressure surrounding the diaphragm inside the instrument. The difference in pressure identifies a climb or descent.
224
What is another name for a takeoff from the surface?
A running takeoff.
225
What is the goal of a takeoff from hover?
To bring the helicopter from a hovering position to straight and level flight in the air.
226
What is blade flapping?
The up and down motion of rotor blades
227
When performing a takeoff from a hover, what controls would a pilot need to use in ideal conditions?
All of them.
228
What kind of hovering turn requires the most right pedal pressure in turn?
A hovering turn with left cyclic in to the wind
229
Does air pressure increase or decrease with altitude?
Decrease.
230
What is a common logarithm?
A logarithm with base 10
231
What is the mechanical advantage of pulleys determined by?
By the number of pulleys present in the configuration.
232
Which of the following occurs when the tail rotor becomes more aerodynamically efficient during the transition from hover to forward flight?
D: Translational thrust occurs when the tail rotor becomes more aerodynamically efficient during the transition from hover to forward flight.
233
What is a common mistake when using the cyclic to adjust speed?
Overcorrecting due to control lag—adjusting too much before the helicopter responds, leading to excessive speed or altitude loss.
234
What is kinetic energy?
The energy of movement. The formula for calculating kinetic energy is:
KE = 1/2m*v^2
235
In a block and tackle system, the rope length needed to lift the object increases with what?
The number of pulleys present. For every pully, the length pulled is multiplied by that amount.
236
What should the approach flightpath be when climbing to a ridgeline?
Parallel to the ridgeline and into the wind
## Footnote
The approach flightpath should be parallel to the ridgeline and into the wind as much as possible.
237
The thrust from the tail rotor depends on what?
Its pitch angle.
238
Total drag is composed of how many types of drag?
3. Profile, induced, parasitic.
239
Why is it necessary to apply the cyclic in the opposite direction after reaching the desired position?
A. To counteract drag and maintain forward momentum.
B. To create a negative acceleration and bring the helicopter to a stop.
C. To increase the helicopter’s speed in the new direction.
D. To reset the cyclic’s position for stability.
B
240
What is a required action while entering a climb while maintaining air speed?
Increase the collective
## Footnote
To enter a climb in a helicopter while maintaining airspeed, the first actions are increasing the collective and throttle.
241
In a standard airplane traffic pattern, which leg is known as the crosswind leg?
The second leg
## Footnote
In a standard airplane traffic pattern, the second of the five legs is known as the crosswind leg.
242
What action must a pilot perform flying out of a steep turn that is not usually needed during a shallow or medium turn?
Input opposite pressure.
243
Which of the following is common to all turbine helicopters but is only on some piston powered helicopters?
A: Governors are common on all turbine helicopters (as they are a function of the fuel control system of the turbine engine). They are also used on some piston powered helicopters.
244
When performing an air taxi, what should be avoided?
Flying in the shaded area of the height-velocity diagram
Flying over other aircraft, vehicles, and personnel
Flying in crosswind conditions
245
The _______ region is normally between a blade's _______ and _______ regions:
A. stall, driven, high AOA
B. stall, driving, low AOA
C. driven, high AOA, stall
D. driving, stall, driven
D
246
What is energy?
The capacity to cause a change in the state of something
247
Which pedals control the direction in which the nose of the helicopter points?
Antitorque pedals
## Footnote
The antitorque pedals control the direction in which the nose of the helicopter is pointing.
248
What are REILs?
Runway End Identification Lights. These are lights which mark the end of a runway. The lights at the end of the runway are red, and outward from the runway they are green.
249
What is the standard descent rate for a partial power descent?
A descent at a rate of 500 ft per min.
250
Which principle describes the relationship between internal fluid pressure and fluid velocity?
Bernoulli's Principle
## Footnote
Bernoulli's principle describes the relationship between internal fluid pressure and fluid velocity. It helps explain why an airfoil develops an aerodynamic force.
251
At what angle should a pilot enter the downwind leg?
At a 45 degree angle
252
What is Venturi Flow?
The reduction in static pressure, and increase in dynamic pressure and velocity of fluids in constricted areas.
253
What is a rate-controlled instrument? Give examples.
Anti-torque pedals
254
What is an rpm indicator called?
Tachometer.
255
What are the 3 movements rotor blades are capable of performing?
Feathering - Rotation on its longitudinal axis
Lead\lag - The slowing and speeding up of advancing and
retreating blades
Flapping - The up and down movement of blades
256
What does the IMSAFE acronym stand for?
Illness, medication, stress, alcohol, fatigue, emotion
257
How many phases are in a normal takeoff from hover?
5
258
Normal helicopter landings usually require ____
power settings, with terminations to a hover
requiring the ____ power setting.
high, highest
259
What are the movements along each of an aircraft's axes called?
Roll (Longitudinal), Yaw (Vertical), and Pitch (Lateral).
260
How does a takeoff from hover differ from forward flight?
It differs primarily in altitude and speed, requiring careful management to avoid unsafe velocity-altitude combinations.
261
__________________ changes the angle of incidence differentially around the rotor system.
C: Cyclic feathering changes the angle of incidence differentially around the rotor system.
262
What is MSL?
Mean sea level. It's your altitude above sea level.
263
The driving region is also known as what?
The autorotative region.
264
What are the 3 types of climb?
Normal climb, best rate of climb, best angle of climb.
265
What is the difference between cyclic and collective feathering?
Collective feathering changes the AOI of all blades equally and in the same direction of all blades simultaneously and affects overall lift of the disk.
Cyclic feathering changes the AOI of each blade differentially and produces differential lift. It changes the attitude of the rotor disk but not the amount of overall lift created.
266
what is the sum of the outside angles of a triangle?
360
267
At what pace should a helicopter in air taxi move?
About as fast as a brisk walk
268
What is voltage?
An electromagnetic repulsion from a negative charge to a positive charge.
269
How do simple machines allow one to move an object with less input force than it otherwise take?
By increasing the amount of input distance.
270
When plotted on a graph, L/DMAX is the point where the helicopter's _____________.
Total lift-to-drag ratio is the greatest.
271
What are the components attached to the main rotor head?
Rotor blades, blade grips, yoke, stabilizer bar and weight (flybar), teeter hinge (trunnion).
272
How does humidity affect an aircraft's performance?
Negatively.
273
How can slipping be corrected?
By increasing pedal pressure in the direction of the turn or decreasing pressure on the opposite pedal.
274
When determining whether a critical balance condition exists, it is essential to _________
Consider the wind velocity and its relation to the rearward displacement of the cyclic control.
275
What is normal climb?
Climb performed within the manufacturers standards. The aircraft increases airspeed, but may not be operating at its optimum performance.
276
Multi-engine helicopters have:
A. A supplementary freewheeling clutch.
B. A coaxial drive shaft and two transmissions.
C. A throttle lever for each engine.
D. All of the above.
C
277
How many blades are typical in:
Fully articulated systems
Semi rigid systems
3 or more
2
278
Which helicopter is the US Army's primary light utility helicopter?
The UH-72 Lakota
## Footnote
The UH-72 Lakota is the US Army's primary light utility helicopter.
279
The horizontal stabilizer has a tendency to do what during a tailwind condition?
Lift the tail
280
What is a complication unique to sideward hovering flight, as opposed to forward and rearward flight?
Additional pressure needed on the anti torque pedals to deal with the weathervane
281
What is the major cause of drag at low air speeds?
Induced drag.
282
What type of rotor system does not allow blade flapping?
Rigid rotor systems.
283
What is Manufacturer Empty Weight?
Total weight of the aircraft as it was built. Doesn't include baggage, personnel, or any fuel or fluids.
284
Which of the following is NOT included in a helicopter's base empty weight?
A. The pilot
B. The engine
C. Optional equipment
D. Transmission oil
E. The rotors
A
285
As angle of attack increases, induced drag ______.
Increases.
286
What are the 2 control parts of the trailing edge of an airplane's wing?
Ailerons and Flaps
287
When does no flapping no occur?
When the tip path plane is perpendicular to the mast.
288
Hovering turns are also known as _______.
Pedal turns.
289
A standard ______ traffic pattern consists of left turns
fixed-wing
290
What is resultant relative wind?
Relative wind adjusted for induced flow
291
What adjustments are needed when ETL is reached?
Increase the collective to climb and push the cyclic forward to counteract nose rise.
292
What is the "pressure" that causes electrons to move?
Voltage
293
What are some common pitot-static instruments?
Altimeter, airspeed indicator, vertical speed indicator.
294
Once a target is detected in the peripheral
field of dark-adapted vision, aircrews
maintain continual surveillance how?
by using the off-center vision technique. They look
10 degrees above, below, or to either side
of the target, viewing it no longer than two
to three seconds at each position.
295
What are the axes of an aircraft?
Longitudinal, lateral, and vertical.
296
How is voltage measured?
Voltmeter
297
Static pressure over the wing _________ and dynamic pressure _________ due to the Bernoulli principle.
Decreases, increases.
298
How many traffic pattern legs are there? Name them.
1. Takeoff leg
2. Crosswind leg
3. Downwind leg
4. Base leg
5. Final approach leg
299
What is the recommended maximum slope in degrees for normal operation of most helicopters during slope landings?
5 degrees
## Footnote
The slope must be shallow enough to hold the helicopter against it with the cyclic during the entire landing.
300
Of the 3 movements blades are capable of, what are the blade movement capabilities of the 3 rotor system types respectively?
Rigid - Feathering
Semi-rigid - Feathering, Flapping (on a teeter hinge)
Fully-articulated - Feathering, Flapping, Lead/lag
301
What is the difference between day and night visual scanning?
at night, off-center viewing is used to focus objects on the rods rather than the fovea blind spot. also, at night one should move from sector to sector slower than during the day to prevent blurring
302
Each gallon of JP-4 jet fuel weighs how many pounds?
6.5 pounds
## Footnote
Each gallon of JP-4 jet fuel weighs 6.5 pounds.
303
During the approach to a pinnacle, what should the apparent rate of closure be?
Should be about the pace of a brisk walk
## Footnote
During an approach to a pinnacle or ridgeline, pilots must continually perceive the apparent rate of closure by observing the apparent change in size of the landing zone features.
304
At what bank angle is load factor doubled?
60 degree bank angle.
305
What is Maximum Zero Fuel Weight?
The permissible weight of an aircraft with its contents and includes unusable fuel. Total MZFW excludes any usable fuel or fluids.
306
What is pressure altitude?
True altitude corrected for non-standard pressure or the altitude indicated when the altimeter is set to 29.92.
307
A high reconnaissance should be flown at an altitude of ________ feet above the surface.
D: 300-500.
308
What color are position lights during night operation and where on the aircraft are they located?
Green on right, Red on left, White on rear
309
As load on a blade increases, flapping ______ and lead ______
increases, increases
310
At what speed in knots does the helicopter go through effective translational lift (ETL)?
About 16-24 knots
## Footnote
While transitioning to forward flight at about 16-24 knots, the helicopter goes through effective translational lift (ETL).
311
What does the shaded area of the height-velocity diagram represent?
the combinations of height above ground and airspeed that should be avoided due to safety concerns relating to emergency landings. It is dangerous to operate within the shaded regions of the diagram, because it may be impossible for the pilot to complete an emergency autorotation from a starting point within these regions.
312
What condition are semi-rigid rotor systems uniquely vulnerable to?
Mast bumping
313
What is a coordinated turn?
A smooth turn in which all the forces are balanced.
314
What is the best rate of climb?
Involves gaining the most amount of altitude in a given amount of time using the most power available to reach cruising altitude.
315
Solve 8^1/3
2
316
In the formula for kinetic energy, what is the measurement of velocity in?
meters/second
317
Do simple machines change the amount of work required to move an object?
No
318
What marks the beginning of phase two of takeoff from a hover?
Applying forward pressure on the cyclic to increase speed.
319
In steep turns, the rate of pitch change is proportional to ____ and _____.
gross weight and density altitude
320
Helicopters typically have between _ and _ main rotor blades
2, 6
321
What is Angle of Attack?
Angle between chord line and relative wind.
322
A standard helicopter traffic pattern consists of _____ turns
right
323
Load factor is increased by ___% at a 30 degree bank and ___% at a 60 degree bank.
16%, 100%.
324
What is a skid turn?
What causes it?
When the tail turns away from the center of a turn.
It's caused by excessive pedal/rudder input in the direction of the turn, or by too little in the direction opposite the turn.
325
What is electrical current?
The rate of flow of electrons through a conductor.
326
Where there is too much lift, the main rotor blades will:
Flap
327
What is the formula used to calculate the mechanical advantage of a wedge?
length/width
328
Profile drag consists of __________ created by __________ and __________:
A. induced drag, angular momentum, aircraft components that do not contribute to lift.
B. skin friction, surface imperfections, form drag.
C. an inclined main rotor disk, increasing angle of attack, high blade rpm.
D. None of the above.
B
329
When two aircraft approach each other head on, what should the pilots do?
Both pilots should change course to the right.
330
Rotational relative wind is slower near what part of the blade?
The blade root.
331
A pilot can worsen a helicopter's pendular action by:
A. Applying too much angle of incidence.
B. Over-controlling the aircraft.
C. Moving the cyclic left while pushing on the right pedal.
D. Moving the cyclic left while pulling up on the collective.
B
332
What is the principle of conversation of mechanical energy?
This principle states that the total mechanical energy (KE+PE) remains constant as long as no other forces are applied.
333
What does the critical angle refer to?
The angle at which the roll in a dynamic rollover cannot be stopped. Critical rollover angle is at 3-5 degrees depending on the aircraft.
334
Wheels on ______ types of helicopters are ________
some, retractable
335
What are the key control inputs for a vertical takeoff to hover?
Increase collective smoothly, keep the cyclic neutral initially, use pedals to maintain heading, and coordinate cyclic for a controlled vertical ascent.
336
How does a pilot decrease airspeed in straight and level flight?
By applying aft pressure to the cyclic, raising the nose, and allowing drag to slow the helicopter.
337
What are the four fundamental flight maneuvers?
Straight-and-level flight, turns, climbs, and descents.
338
Many helicopters have a horizontal stabilizer located where?
On the tail boom
339
What percentages of the radius do each of the 3 blade regions in an autorotation make up respectively?
Stall: 25%
Driving: 25-70%
Driven: 30%
340
What does PAVE stand for?
P - Pilot
A - Aircraft
V - Environment
E - External Pressure
341
How many main types of rotor systems are there?
3.
342
What determines the helicopter’s attitude when
stabilized at an airspeed and altitude.
horizontal stabilizer
343
Arrange the following aircraft types in order of right-of-way:
Balloons
Rotorcraft
Airplanes
Ultra light aircraft
Gliders
Balloons
Gliders
Ultra light aircraft
Airplanes
Rotorcraft
344
How many types of profile drag are there?
2 (form drag and skin friction).
345
What are the phases in a normal takeoff from hover?
1. Helicopter is in a hover. Conduct performance check.
2. Apply forward pressure to cyclic, increase collective to keep helicopter from losing altitude. Increased collective requires increase power. Increase throttle means increased torque. This means that all 4 controls are used during this phase simultaneously.
3. Helicopter reaches ETL. Nose rises. Collective should be increased to begin climb. Cyclic should be pushed forward to counteract nose rise from ETL.
4. Helicopter is climbing and accelerating forward simultaneously. Care should be taken to ensure helicopter does not enter shaded area of height-velocity diagram.
5. Helicopter has escaped the curved section of height-velocity diagram and is mostly free to move as desired. Helicopter has reached straight and level flight.
346
What is feathering?
The rotation of a blade about its longitudinal axis by collective/cyclic inputs.
347
What instrument measures yaw?
Turn and slip indicator.
348
A hover taxi is used when operating below what height in feet above ground level (AGL)?
25 feet
## Footnote
A hover taxi is used when operating below 25 feet above ground level (AGL).
349
How does Vortex Ring State happen?
By descending at a high rate, with little forward speed, and power applied. Blade vortices are reintroduced in the induced flow.
350
When climbing at cruising speed, in addition to increasing collective, the rate of climb can be increased how?
Applying rearward cyclic pressure to reduce airspeed
351
When descending, when should you begin to level out?
10% of your descent rate above your desired end level.
Ex. If a helicopter at 300 ft AGL wants to descend to 200 ft AGL at a rate of 400fpm, the pilot should begin to level out at 240 ft (200 + 10% * 400)
352
What are the 2 control parts of the trailing edge of an airplane's wing?
Ailerons and Flaps.
353
What is the same as load factor?
Effective weight
## Footnote
This extra weight, when added to the weight of the helicopter, crew, passengers, and cargo, becomes the effective weight of the helicopter.
354
If control of a hovering turn in heavy winds is ever questionable, what should a pilot do?
First attempt to make a turn 90 degrees to the left. If sufficient power exists to turn the helicopter in a left turn, a right turn can be successfully controlled (remember left turns require more power)
355
What is the mast of a helicopter responsible for?
The rotational force of the main rotor hub.
356
What is Operating Empty Weight?
The MEW plus the weight of crew, fluids, unusable fuel, and the equipment required for flight. Doesn't include baggage, passengers, or usable fuel.
357
How can a pilot rebuild rotor rpm in autorotation if it drops below acceptable limits?
Apply aft cyclic, possibly combined with a turn, to increase airflow through the rotor system.
358
What is a straight-in autorotation?
An autorotation made from altitude with no turns.
359
How do strong headwinds affect an autorotation?
They make the glide angle steeper due to slower groundspeed, although the rate of descent remains the same.
360
What determines the speed at touchdown in a straight-in autorotation?
The groundspeed and the degree of deceleration (flare) before landing.
361
Why must caution be exercised during the flare in an autorotation?
The tail rotor is the closest part of the helicopter to the ground and could strike the surface.
362
How does a headwind affect autorotation landings?
It helps achieve a slower touchdown speed and reduces the amount of deceleration required.
363
What is the correct technique for entering an autorotation?
Lower the collective smoothly but firmly.
Apply aft cyclic to maintain attitude.
Use antitorque pedals for trim.
Reduce throttle to allow a clean needle split.
364
Why are turns performed during autorotation?
To facilitate landing into the wind or to avoid obstacles.
365
When should turns be performed during autorotation?
Early in the descent so that the remainder of the autorotation is flown like a straight-in autorotation.
366
What are the most common autorotation turn angles?
90 degrees and 180 degrees.
367
What bank angle should be used for a 180-degree autorotation turn in training?
Between 30 and 60 degrees.
368
How can a pilot adjust if the helicopter is too close or too far from the landing area during the turn in an autorotation?
Too close: Decrease the bank angle to widen the turn.
Too far: Increase the bank angle to tighten the turn.
369
By what altitude should the turn be completed in autorotation, and why?
By 200 feet AGL to ensure the helicopter is stabilized and aligned for landing or a surface-level power recovery.
370
What are the criteria for aborting an autorotation turn maneuver?
The helicopter is not stabilized for landing.
Rotor rpm is outside limits.
Attitude or airspeed is incorrect.
The helicopter is not under proper control by 200 feet AGL.
371
How does “G” force affect rotor rpm during an autorotation?
Rotor rpm increases when G-forces are applied, such as during a turn or deceleration flare.
372
What is the most critical element in an autorotation?
Rotor rpm, as it provides lift to stabilize descent and energy for landing cushioning.
373
At what height should the helicopter begin to level out during an autorotation power recovery?
Between 3–15 feet AGL, depending on the helicopter type.
374
What is the vortex ring state?
A condition where a helicopter descends vertically into its own downwash, causing severe loss of lift despite power application.
375
Why was vortex ring state previously called "settling-with-power"?
Because the helicopter continues to descend even when full engine power is applied.
376
What airflow change occurs in vortex ring state?
Inner sections of the rotor experience upward airflow, forming a secondary vortex ring that further degrades lift.
377
What are the key signs of a fully developed vortex ring state?
Uncommanded pitch and roll oscillations
Little or no collective authority
Descent rate up to 6,000 feet per minute (fpm)
378
What three conditions typically cause a helicopter to enter vortex ring state?
Vertical or near-vertical descent of at least 300 fpm
Rotor disk using 20–100% available power
Forward airspeed below effective translational lift (ETL)
379
Name two flight scenarios that increase the risk of vortex ring state.
Hovering OGE (Out of Ground Effect) without precise altitude control
Steep approaches with a tailwind component
380
Why does increasing collective worsen vortex ring state?
It expands the stalled area of the rotor, increasing the descent rate.
381
What is the traditional method of recovering from vortex ring state?
Increase forward airspeed and/or partially lower collective to escape the vortex.
382
What happens if vortex ring state progresses to the "windmill brake state"?
The only recovery may be an autorotation.
383
What is the formula for flow rate?
Flow area * Flow velocity
384
How many liters are in a cubic meter?
1000
385
What are the units of measurement for the 3 variables in the flow rate formula?
Flow rate = cubic meters/second
Flow area = square meters
Flow velocity = meters/second
386
Mast bumping is the result of what?
Excessive blade flapping in semi=rigid rotor systems.
387
What does "needle split" refer to in the context of an autorotation?
The opposite movement of needle direction in engine rpm and rotor rpm
388
What is the primary purpose of the main rotor transmission?
To reduce engine rpm to the optimal rotor rpm.
389
What electrical system is used on most helicopters?
14-28V DC
390
What do helicopters use to overcome high control forces?
A hydraulic system
391
What is a helicopter's hydraulic system composed of?
Actuators (also called servos) on each flight control, a pump usually powered by the main rotor transmission, and a hydraulic reservoir to store the hydraulic fluid
392
What is windmill brake state?
When the airflow through the rotor blades is completely upwards.
393
What are the phases of an autorotation?
Entry phase, alignment phase, deceleration phase, termination phase, and a go-around phase if necessary
394
What are the 3 approach angle classifications?
Shallow - 3 to 5 degrees
Normal - 7 to 12 degrees
Steep - 13 to 15 degrees
395
When an aircraft is turned, its ______ should be banked _______ the turn
ailerons, towards
396
What determines how much input and adjustment a pilot must make to restore the aircraft to level flight from a turn?
Bank angle
397
During a turn, the pilot must maintain visual reference with what?
The horizon
398
What do the following color arcs in an airspeed indicator represent?
White
Green
Red
White - displays flap operating speed
Green - normal operating speed
Red - never-exceed speed
399
What is V(so)?
Stalling speed with the flaps down
400
What is V(fe)?
Upper limit at which flaps can be extended. Located where the white and green arcs meet.
401
What does the red radial line on an airspeed indicator represent?
Never-exceed speed
402
What is V(ne)?
Never-exceed speed
403
What airspeed does the airspeed indicator display?
Indicated airspeed
404
What is the relationship between the collective and the nose of the helicopter?
The nose pitch follows the collective (i.e. collective up, nose up/ collective down, nose down)
The additional lift causes this. Also the reason nose tends to rise once the helicopter has reached ETL and lift has increased.
