Block 1 Day 2 Flashcards
1
Q
In order to be efficient, a helicopter engine must turn at a ___________ _________
A
Constant speed
2
Q
The speed of the helicopter engine is __________ for safe operation of of the rotor system
A
too high
3
Q
A speed reduction device, known as ________________ must be uses between a helicopter engine and a rotor system
A
Transmission gearboxes
4
Q
How do transmissions and drive shafts carry the rotational energy (engine torque) through gearboxes?
A
Engine torque is transmitted to an input gearbox
Engine torque RPM is reduced and the direction is changed so it can be input
5
Q
Drive shafts sections are connected to the _______________ and are interconnected to the ________________________________________
A
back of the main transmission
intermediate and tail boxes
6
Q
Drive shafts transmit ________________ to their respective gear boxes
A
rotational energy
7
Q
Intermediate gearboxes change __________, and change the _________ of the drive shaft to the tail gearbox
A
speed
angle
8
Q
The tail gearbox reduces ________ and changes the _________of the drive shaft to the tail which provides anti-torque and directional control
A
RPM
angle
9
Q
Transmission and Drive System components:
A
Are the largest and most important component of a helicopter
Carries engine torque to the main and tail rotor
Transmits engine power at a reduced rate to the main and tail rotor systems
10
Q
A free wheeling unit is incorporated to permit either or both engines to disengage from the transmission in the event of:
A
Single engine failure
Autorotation
Whenever engine RPM drops below main rotor RPM
11
Q
Transmission and Drive System Components include:
A
Main Gearbox/Main transmission Intermediate Gearbox Tail Gearbox Accessory Gearboxs/Drives Driveshaft sections
12
Q
What is the location of the main gearbox/main transmission?
A
It is centrally located
13
Q
Where is the intermediate gearbox located?
A
At the base of the tail pylon
14
Q
Where is the tail gearbox located?
A
At the top of the tail pylon
15
Q
What component takes power from the engine(s) at a reduced rate and then transmits that power to the helicopter’s main and tail rotor drive systems.
A
Main gearbox/main transmission
16
Q
What drives both the main rotor mast as well as the tail rotor drive components.
A
Main/gearbox/main transmission
17
Q
What component carries transmission torque to the tail rotor gearbox?
A
Intermediate gearbox
18
Q
What component changes the angle of the drive into the tail gearbox?
A
Intermediate gearbox
19
Q
What component reduces tail shaft input speed (gear reduction)?
A
Intermediate gearbox
20
Q
What component provides the mounting point for the tail rotor head?
A
Tail gearbox
21
Q
What component changes the angle of the drive?
A
Tail gearbox
22
Q
What component provides a RPM reduction for the tail rotor?
A
Tail gearbox
23
Q
What drives the accessory gearboxes/drives?
A
The main gearbox
24
Q
What component provides for an angle of drive change and also for gear reduction?
A
Accessory gearboxes/drives
25
What provides a mounting and drive for essential components such as: hydraulic pumps, generators, rotor brake discs, etc.?
Accessory gearboxes/drives
26
All the gearboxes covered are interconnected and driven by...
Sections of driveshafts
27
What connects the engines to the transmission systems, driving the main and tail rotor systems?
Driveshaft sections
28
What are the different modes of flight for a prop-rotor system?
VTOL mode
CONV mode
APLN mode
29
What is the VTOL mode and when is it used?
Vertical take off and landing. It provides lift and control like a helicopter
30
What is the CONV mode and when is it used?
Conversion. Provides lift and thrust
31
What is the APLN mode and when is it used?
Airplane. Provides thrust like any turboprop or C-130
32
Prop-rotor systems are powered by the engines through the ____________
Prop-rotor gearboxes
33
Prop-rotor systems provide __________ and _______ by a right and left counter-rotating prop-rotor system
lift
| thrust
34
What three colors are used to color code prop-rotor blades?
Red, Green, White
35
Are the left and right blades in a prop-rotor system interchangeable?
No
36
The diameter of prop-rotor and twist of blades are a ___________ between helicopter and propeller aerodynamics.
compromise
37
Prop-rotor blades are synchronized by ______________, which also allows for single engine operation
Inter-connecting Driveshaft
38
Prop-rotor blades are ___________ rotating. The left rotates ________ and the right ___________
counter
CCW
CW
39
What are the components of a Prop-rotor system?
Prop-rotor blades
Drive System
Swashplate
40
What is the primary function of the drive system in a prop-rotor aircraft?
Transmits torque from the engines to the propellers
41
What is the secondary function of the drive system in a prop-rotor aircraft?
Provides synchronization of the prop-rotors while enabling single engine operation
42
The drive system on a prop-rotor aircraft consists of...
```
2 prop-rotor gearboxes
2 tilt axis gearboxes
2 nacelle heat exchangers
midwing gearbox
emergency lubrication system
interconnecting shafting system
```
43
What transmits flight control inputs to each prop-rotor hub and blade assembly on a prop-rotor aircraft?
swashplate
44
How are control inputs from the pilots transferred to the swashplate?
Via hydraulic actuators
45
The flow or movement of electrons through a conductor
Current
46
Current is measured in ______
amperes or amps
47
Electrical pressure
Voltage
48
The force that pushes electrons through an electrical circuit is measured in _______
Volts
49
Opposition to current in an electrical circuit or device
resistance
50
Resistance is measured in ______
ohms
51
If voltage is increased the current increases proportionately. If resistance is increased , the current will decrease proportionately
Ohms law
52
Device used for the temporary storage of electrical energy
Capacitor
53
The electrical energy stored in a capacitor is later discharged as ____________
Voltage drops
54
Property that opposes change in current flow through a coil
Inductance
55
AC circuit, whenever the current passes through a series of changes and returns to the starting point
Cycle
56
The number of times a cycle occurs in one second
Frequency
57
Frequency is depicted as _________
Hertz (Hz)
58
A complete elapsed cycle as measured from a reference point
Phase
59
Phase is expressed in ___________
Degrees
60
A complete path through which current can flow
Electric circuit
61
Circuit is broken so that the current is no longer able to pass
Open circuit
62
Electrons flow in a complete uninterrupted path
Closed circuit
63
Path of electrons is able to follow a shorter path than intended by design
Short circuit
64
Devices connected end-to-end so that current has only one path along which to flow
Series circuit
65
Devices connected so that current has more than one path in which it can flow
Parallel circuit
66
Electrical device which restricts current flow to one direction or an electrical check valve
Diode
67
A large, conductive body in the electrical circuit
Ground
68
A circuit of current flowing through all of the elements, from the power source to component and then back in an unbroken course
Continuity
69
A simple plate or bar, usually made of copper
Bus
70
Electrical power is _________ on the bus and then ____________ to other buses and components
centralized
| distributed
71
Non-moving electrical charge usually caused by friction
Static Electricity
72
With ____________ , positively charged electrons jump from one object to another
Static Electricity
73
__________ drastically effects communications and electronic equipment on the aircraft
Static Electricity
74
Voltage is measured in
Volts
75
Where are in-flight static eliminators installed to dissipate static build-up?
The wing tips and tail assembly trailing edges
76
On the ground aircraft are equipped with static eliminators called _______________
ground wires
77
_____________reduce the possibility of a fire during refueling
ground wires
78
What are the two types of dynamic electricity?
```
Alternating current (AC)
Direct current (DC)
```
79
Invisible force that has the ability to accomplish mechanical work by attraction and repulsion.
Magnetism
80
Flow of current through a circuit
Dynamic electricity
81
A temporary magnet that needs electrical current to produce a magnetic field
Electromagnet
82
The strength of an electromagnet is determined by:
The number of windings of wire around a metal core
The type of metal core
The amount of current passing through the wire
83
Electricity is most commonly _________________
Dynamic electricity
84
The movement of free electrons through conductors
Electricity
85
Movement of electrons is referred to as _________
Electric current
86
Strength of electric current flowing in a circuit is measured in ___________
Amperes or amps
87
Tool used to measure current
ammeter
88
The four types of electrical circuits
Series circuit
Parallel circuit
Series parallel circuit
Open/closed circuit
89
Type of electrical circuit in which current can flow in only one path
Series Circuit
90
Type of electrical circuit in which two or more electrical devices are connected across, or are connected independently, to the same source of electrical power and current has more than one path in which to flow
Parallel circuit
91
Type of electrical circuit which is a combination of both the series and parallel circuits
Series Parallel Circuit
92
Open/Closed Circuit
```
Open= Broken Wire = No current flow
Closed = Complete Circuit = current flows
```
93
Does current flow in an open or closed circuit?
Closed circuit
94
Is a broken wire part of an open or closed circuit?
Open circuit
95
An invisible force that can produce light, heat, and magnetism
Electricity
96
Electricity used by aircraft is produced in these three ways:
Thermoelectric Method
Chemical Method
Mechanical Method
97
The method in which voltage is produced through the direct conversion of heat into electricity
Thermoelectric Method
98
Two dissimilar metals that are bonded together
Thermocouple
99
TIT
Turbine Inlet Temperature
100
EGT
Exhaust Gas Temperature
101
A _________ is a source of chemical energy used to produce DC power for the aircraft
battery
102
A battery supplies _________ during an emergency such as the loss of all AC or DC power
DC power
103
A battery is connected to a _____ circuit
DC
104
When the battery control switch is placed to ON, a ___________ action takes place and DC voltage is produced
chemical
105
The three types of batteries are:
Lead acid battery
Nickel Cadmium battery (NICAD)
Dry cell battery
106
The type of battery that works like a car battery
Lead acid battery
107
Lead acid batteries are being replaced by ________
NICADs
108
The type of battery used for high current demand because of their ability to hold an electrical charge longer
Nickel-Cadium Battery (NICAD)
109
______________ used in both NICAD and lead acid batteries store electrical energy
Liquid chemicals
110
Energy is released as ______________ when the battery circuit is complete
voltage
111
__________ are very durable and require less maintenance than lead acid batteries
NICADs
112
Most common type of battery
Dry cell battery
113
Battery used when small amounts of current are needed for short, irregular intervals
Dry cell battery
114
What 3 things are needed to produce an electrical current mechanically?
Conductors
Magnetic fields
Rotating motion
115
Whenever there is current flow in a conductor, _________ are produced.
Magnetic fields
116
Magnetic fields are used to operate components such as:
solenoid valves, pumps and motors
117
A solenoid valve can be moved to an ________ or ____________ position
open
| closed
118
Rotating armature passing through a series of stators also produces ____________
electric current
119
Whenever a conductor, like a wire or an armature, cuts magnetic lines of force, _____________ is produced in the conductor
Voltage
120
What is the principle of generator operation?
Rotating motion
121
How do AC/DC generators work to create electricity?
Rotating motion
122
What is the general term for a device used to control the electrical system and components?
Circuit control devices
123
A pole on a switch that moves and makes or breaks a connection; it starts and stops current flow
Toggle
124
A switch that is locked in a set position to prevent inadvertently placing the switch in the wrong position at a critical time
Lever Lock
125
A type of switch that is a variable resistor with a knob that when rotated to the right, current flow increases and when rotated to the left current flow decreases. It also stops and starts the current flow
Rheostat
126
A type of switch used primarily as a limit switch, which automatically controls circuits, preventing dangerous operation
Micro-switches
127
A type of switch that takes the place of several switches
Rotary selectors
128
What is the primary purpose of fuses?
To protect electrical components and wiring
129
How do fuses work?
A current flows through a conductor producing heat. The greater the current, the hotter the conductor. If the current is greater than the fuse rating, the heat produced melts the metal strip, opening the circuit
130
What are two types of fuses?
Glass tubular and Current limiter
131
A type a fuse which uses a strip of low melting-point metal and is rated by amperage
Glass Tubular
132
The type of fuse found in heavy-current-draw circuits such as generators
Current limiter
133
Current limiter fuses are usually made of __________ because strips of this material can survive large amounts of current for short periods of time
copper
134
Which type of fuse allows momentary overload to occur without opening the circuit
Current Limiter
135
Why are circuit breakers used instead of fuses?
Because it is easier to close a circuit in flight by resetting the breaker than by replacing a fuse
136
With a circuit breaker, when the current exceeds the breaker's rating, the circuit breaker __________, opening the circuit and stopping the current
"trips"
137
What are the two types of circuit breakers
Push to reset circuit breakers
| Push-pull circuit breaker
138
Type of circuit breaker that is normally recessed, pops out when overloaded and then pushed to reset (example GFI)
Push to reset circuit breaker
139
Type of circuit breaker that is normally retracted, the button pops when overloaded; it has a white band to indicated it's popped or open and has a knob to manually pull when necessary
Push-Pull Circuit Breaker
140
The type of switch that is electrically operated and used for remote control of heavy-current circuits
Relays
141
Relays are usually located __________ the source of power and the component to be operated
between
142
_______ allow the cables carrying heavy current to have a short run to the component
Relays
143
_________ are small electromagnet switches
Relays
144
What do most large aircraft use for primary electric power
Alternating Current (AC)
145
AC is a _______, _________ power source which is necessary to operate electric motors, valves, computers and flight and engine instruments reliably
stable, regulated
146
AC power distribution units save a great deal of ______ because the wiring and system components are smaller and lighter than for DC
weight
147
What is the voltage of an AC generator?
115/200 volts
148
The type of generator in which voltage output is produced by the rotating field (magnet) passing the fixed stators
Three phase generator
149
A ___________ is constructed of three stator coils around a common rotating field
Three Phase Generator
150
Generator phases are referred to as ______ phase, _____ phase, ______ phase
A, B, C
151
When the rotating field of the generator (armature) rotates from 0 degrees to 360 degrees it has completed ___________
One cycle
152
The number of times a cycle repeats itself each second is called
Frequency
153
Frequency is measured in cycles per second or_____
"Hertz" or HZ
154
The difference in degrees between generators phases is referred to as _______
Phase
155
___________ operates certain valves, supplies control power to relays for operating AC motor and pump assemblies
DC power
156
_________ is used as an emergency power supply when all AC power is lost
DC power
157
DC Power Distribution Components include:
```
Transfer-Rectifier (T/R)
Reverse Current Relay (RCR)
Batteries
Main DC Buses
Emergency DC Buses
```
158
Most aircraft use a _______ to step down (transform) AC voltage and rectify it to DC voltage
Transfer-Rectifier (T/R)
159
A Transformer-Rectifier (T/R) steps down 115/200 volt, 3 phase, 400 HZ AC to _____ volts DC
28
160
A _____________ is the primary source of DC power on most aircraft
Transfer-Rectifier (T/R)
161
A ______________ acts as a safety device, preventing any reverse flow of current, allowing current to flow in one direction only. It opens id the current reverses.
Reverse Current Relay (RCR)
162
A ____________ is installed between a DC power source and the DC buses being supplied power
Reverse Current Relay (RCR)
163
DC power distribution components include both ___________ and __________ batteries
Lead Acid and NICAD
164
The primary purpose of ___________ is to supply 28 volt DC power to relays that operate certain motors and pumps
Main DC buses
165
Main DC buses receive 28 volt DC power from _______________
transformer-rectifiers (T/Rs)
166
_____________ receive 28 volt DC power form transformer-rectifiers and/or the 24 volts from the battery and are located on most aircraft
Emergency DC buses
167
During preflight checks, the boost pump is run to pressurize the fuel system so that internal leaks in the fuel manifold can be detected. This is called:
Running pressure checks
168
When a boost pump is used to transfer fuel between any two tanks
Transferring fuel
169
Engines normally receive fuel from their designated tanks. During _____________, the engines receive fuel from other tanks
Cross feeding
170
Having to use fuel from another tank due to boost pump failure in the main tank would be an example of...
Cross-Feeding Fuel
171
SMAs may be in charge of fueling their respective aircraft as it is the SMA's job to ensure the safety of the refueling operations when __________________ are not available
Maintenance Personnel
172
____________ may be required if your mission profile changes, fuel tanks need maintenance, or an increase in cargo causes the new gross weight to exceed takeoff limits
Defueling
173
Refueling an aircraft on the ground with engines running.
Hot Refuel
174
Since hot refueling is significantly more dangerous, it is performed only when operations require _______________
Rapid turnaround of aircraft
175
Hot refueling _________ the aircraft's capability and better _________ the mission requirement allowing it to be refueled on the ground without shutting down its engines
Enhances
| Supports
176
Hot refueling can be accomplished:
Aircraft to aircraft
Refueling truck to aircraft
Fuel bladders or ground tanks to aircraft
