Avionics and Instruments Flashcards
1
Q
What are the 3 groups of Basic Flight Instruments?
A
Primary Flight Instruments
Engine Instruments
Navigation Instruments
2
Q
Name the 2 types of sensing
A
Direct (Analogue)
Remote (Digital)
3
Q
Advantages of digital displays over analogue
A
Reliability
Accuracy
Flexibility
Cost
4
Q
Name the 6 Primary Flight Instruments
A
Attitude Indicator (ATI)
Airspeed Indicator (ASI)
Altimeter (ALT)
Vertical Speed Indicator (VSI)
Horizontal Situation Indicator (HSI)
Turn and Slip Indicator (T+S)
5
Q
In terms of flight instruments
???? + ???? = PERFORMANCE
A
POWER
ATTITUDE
6
Q
What are the CONTROL instruments?
A
Power Instruments
Attitude Indicator (ATI)
Control instrument indications are direct and respond immediately to control changes
7
Q
What are the PERFORMANCE instruments?
A
Airspeed Indicator (ASI)
Altimeter (ALT)
Vertical Speed Indicator (VSI)
Horizontal Situation Indicator (HSI)
Turn and Slip Indicator (T+S)
8
Q
Pressure instruments use what two kinds of pressure?
A
Pitot Pressure and Static Pressure
Digitally this is fed to the Air Data Computer (ADC)
9
Q
What are the DIRECT and INDIRECT indications from the ASI?
A
DIRECT - Airspeed
INDIRECT - Pitch
10
Q
What are the DIRECT and INDIRECT indications from the ALT?
A
DIRECT - Altitude
INDIRECT - Pitch
11
Q
What are the DIRECT and INDIRECT indications from the HSI/Compass?
A
DIRECT - Heading
INDIRECT - Bank or Yaw
12
Q
What are the DIRECT and INDIRECT indications from the VSI?
A
DIRECT - Vertical Speed
INDIRECT - Pitch
13
Q
What are the DIRECT and INDIRECT indications from the Turn Indicator?
A
DIRECT - Rate of Turn
INDIRECT - Bank or Yaw
14
Q
What are the DIRECT and INDIRECT indications from the Slip Indicator?
A
DIRECT - Balance
INDIRECT - Yaw
15
Q
What is the purpose of a standby flight instrument?
A
In-case of a system failure of the main displays
16
Q
How long is a standby flight instrument required to be reliable for?
A
30 mins
17
Q
What are the 2 ways of determining performance altitude?
A
Pressure altitude = Elevation + 30(1013-QNH)
Density Altitude = Pressure Alt + 120(ISA temp deviation)
18
Q
How is the static pressure measured?
A
2 static ports at opposite sides of the aircraft. With an average taken to negate potential influence of slip.
19
Q
Static pressure is provided to what 4 instruments?
A
ALT, ASI, Machmeter, VSI
20
Q
Pitot pressure is provided by what piece of equipment?
A
Pitot tube
21
Q
Pitot pressure = ….. pressure + ….. pressure
A
Static + Dynamic
22
Q
Pitot pressure is supplied to what 2 instruments?
A
ASI, Machmeter
23
Q
The altimeter actually measures ….. but is calibrated to read ……
A
pressure
height/altitude
24
Q
Name the 5 types of altimeter
A
Simple
Sensitive
Servo-Assisted
Digital Display
Cabin Altitude
25
What are the 8 errors of an altimeter or most other pressure instruments?
Pressure
Instrument
Temperature
Hysteresis
Blockages and leaks
Lag
Orographic
Transonic jump
26
On a cold day do you need to correct/adjust your altimeter/decision heights?
Yes - Potentially up to 10%
27
What type of capsule is used in an Altimeter?
Aneroid capsule
28
What type of capsule is used in an ASI?
Differential capsule
29
What are the different instruments that use a differential capsule and an aneroid capsule?
Differential - ASI, VSI
Aneroid - ALT
30
Name the 4 different ASIs
Simple
Sensitive
Servo-assisted
Digital Display
31
What do each of the colours on the rim of the ASI refer to?
White - Flap operating range
Green - Normal operating range
Yellow - Caution range
Red dash - Never exceed
32
Indicated Air Speed (IAS) corrected for instrument and pressure error becomes…
Calibrated Air Speed (CAS)
33
Calibrated Air Speed (CAS) corrected for compressibility error becomes ….
Equivalent Air Speed (EAS)
34
Equivalent Air Speed (EAS) corrected for density error becomes ….
True Air Speed (TAS)
35
What additional component does the Machmeter have over an ASI?
Aneroid Capsule
36
What type of capsule does a VSI have?
Differential Capsule
37
What are other names could a VSI be known as?
Rate of climb & descent Indicator (RCDI)
Vertical Velocity Indicator (VVI)
Instantaneous Vertical Speed Indicator (IVSI)
38
What does an ISVI have that eliminates lag error?
Counter/bob weights counter act lag error to move the needle ‘Instantaneously’.
Weights calibrated to provide correct reading
39
What does ADS stand for?
Air Data System
40
What does the ADS consist of?
Probes and Sensors (Press, Temp, AoA, Slip).
Transducers to convert air data to electronic signals.
Air data computer to process signals for systems/displays.
41
What are the advantages of an ADS?
Less bulky
Replaces numerous instruments
Eliminates analogue error
Errors automatically eliminated
Increased accuracy and sensitivity
Minimal lag time
Digitised air data enables flexibility
42
What converts analogue readings to digital signals?
Transducer
43
Name the 3 different types of gyroscopes
Spinning
Optical
Vibrating
44
Define the 5 terms associated with gyroscopes
Inertia - Resistance of an object to change its state of motion
Momentum - Mass x Velocity
Angular Vel - Speed of rotation/spin
Moment of Inertia - Mass x Moment arm distance from spin axis
Angular Momentum - Ang Vel x Moment of Inertia
45
What is special about angular momentum?
Angular momentum is conserved
46
What is the 1st Law of gyrodynamics?
Spin axis remains fixed in inertial space. RIGIDITY
47
What is the 2nd Law of gyrodynamics?
If a torque is applied perpendicular to spin axis, the spin axis will precess steadily about an axis perpendicular to the spin and torque axis’. PRECESSION
48
Name the 3 classifications of SPINNING gyroscopes
Rate
Rate Integrating
Displacement
49
The main gyroscopic error is known as …..
Wander
50
Gyroscopic wander breakdowns into 2 types. These are?
Real
Apparent
51
Depending on the plane of error what are the 2 terms used?
Drift - Wander of the spin axis in the horizontal plane
Topple - Wander of the spin axis in the vertical plane
52
Apparent wander varies with …. from the equator to the poles as the Earth rotates
Latitude
53
Transport wander is the …. of the gyroscope from the meridian it is set from.
Divergence
54
OPTICAL gyroscopes operate off of what effect?
SAGNAC
55
Name the error other than wander that can impact a gyroscopes functionality?
Gimble Lock
56
Advantages of a Ring Laser Gyro? (5)
Minimal ‘spin up’ time
Unaffected by high ‘g’
No moving parts therefore minimum maintenance
Wide dynamic range
Very small drift rates
57
Disadvantages of a Ring Laser Gyro? (3)
Precision machining required
Costly due to high quality mirrors/sensors required
Careful balance of gases required (He + Ne)
58
Fibre Optic gyroscopes are c….. and more e….. than Ring Laser gyroscopes.
CHEAPER + more EFFICIENT
59
What are the 2 different types of OPTICAL gyroscopes?
Ring Laser Gyroscope (RLG)
Fibre Optic Gyroscope (FOG)
60
Vibrating Structure Gyroscopes are also known as what?
Coriolis Vibrating Gyro (CVG)
61
Vibrating gyroscopes take advantage if what effect?
Coriolis Effect
62
How big are modern Micro Electro-Mechanical Systems?
Finger nail
63
What gyroscopes take advantage of the SAGNAC effect?
Optical Gyroscopes
64
An elementary radar consists of 3 components. These are?
Transmitting Antenna
Receiving Antenna
An energy detecting device or antenna
65
Radar clutter can come from …. (Name some examples)
Land
Sea
Rain
Birds
Chaff
66
Describe Pulse Width
Time duration of a single pulse (represented by tau).
67
Describe Pulse Length
Distance between the leading and trailing edges of a pulse.
68
Describe Pulse Repetition Interval (PRI)
The time period between the start of one pulse and the start of the next pulse.
69
Describe Pulse Repetition Frequency (PRF)
The number of pulses occurring in one second.
70
As the frequency of a radar increases, what happens to the;
Resolution
Equipment and Weight req’d
Power and Operating range
Interference
Resolution - Increases
Equipment and Weight req’d - Decreases
Power and Operating range - Decreases
Interference - Increases
71
Name the 3 radar transmission characteristics
Directional Information
Range Information
Relative Velocity between target and radar
72
How does a radar determine the relative velocity between itself and a target?
Doppler Effect
73
Radars fall broadly into what 3 types?
Pulse System, Continuous Wave, Pulse Doppler
74
Increasing the refraction occurs with what in changes in; Pressure, Temp, Moisture
Pressure - No difference
Temperature - Decreasing
Humidity - Increasing
75
What does MTI stand for? (radar)
Moving Target Indicator
76
What 4 characteristics are used to describe a radar?
Installation Env - Ground/Airbourne etc
Functional Characteristics - Search, Track etc
Transmission Char. - Pulse, CW etc
Oper. Freq - D-Band etc
77
Radar visual displays are usually of what 2 kinds?
Raw Video
Synthetic Video
78
3 applications of Radar are?
Search
Tracking
Fire-Control
79
Describe what a Search Radar does?
Scans wide areas at a lower frequency of return to the same point.
Can only distinguish targets that are far apart.
80
Describe what a Tracking Radar does?
Scans a narrow area more frequently.
Must be directed onto a target as their beams are narrower.
81
Describe what a Fire-Control Radar does?
Specifically direct weapon systems onto a target.
Emits a very narrow, intense beam to ensure accurate tracking information.
82
Describe a Search Radar’s characteristics? (PRF, Antenna Rotation etc)
Low PRF
Slow Antenna Rotation
Low Freq, Scan rate
Large in Size
Serves predominantly as an early warning indicator
83
Describe a Tracking Radar’s characteristics? (PRF, Antenna Rotation etc)
High PRF
Higher Antenna Rotation
Used when continuous flow of data required on discrete targets.
84
Describe a Fire-Control Radar’s characteristics? (PRF, Antenna Rotation etc)
Highest PRF
Very high Antenna Rotation (Often electronically scanned)
Very narrow beam width
Extreme accuracy, limited range
Initial target detection difficult
Multiple modes: Designation, Acquisition, Track
85
Least is _____
____ is best.
East
West
86
To operate efficiently a Direct Indicating Compass System (DICS) must have
Horizontality
Sensitivity
Aperiodicity
87
What does DICS stand for?
Direct Indicating Compass System
88
How can you make a compass more sensitive?
Longer magnet
Increase pole strength
Reduce friction
89
A magnetic compass is subject to disturbance and movement caused by ….
Acceleration/ Deceleration
Manoeuvre (pitch/roll/turns)
Turbulence
90
A gyro-magnetic compass may also be known as ….
Direction Indicator (DI)
91
The Detector Unit in the GMC may also be known as a ….
Fluxvalve
92
What will impact the accuracy of GMC when traveling in an E/W direction?
Acceleration
93
What will impact the accuracy of GMC when traveling in an N/S direction?
Turning
94
What happens to the signal from the fluxvalve when the a/c is manoeuvring?
The signal is cut-off
95
What are you looking for in a good compass swing area?
Low Magnetic Interference
96
List some reasons for conducting a magnetic swing
Following a/c major servicing
Doubt in accuracy
Following a lightning strike
When compass components are replaced
After compass subject to a significant shock
When carrying unusual ferromagnetic loads
97
What does ADF stand for?
Automatic Direction Finding (ADF)
98
An ADF is a NDB. What does NDB stand for?
Non-Directional Beacon (NDB)
99
What frequency do NDBs typically operate?
190-690 kHz
100
What instruments may show the you the relative bearing of a ADF?
HSI
Radio Magnetic Indicator (RMI)
Multifunctional Display (MFD)
101
An Auto Dir. Finding (ADF) system is made up of what components?
2 perpendicular magnet cores wrapped with 2 coils of wire (Fixed Loop Coils).
Field Coils -Search Coil
Goniometer - Control Circuits
Sense Aerial
102
Name some of the different errors an ADF may face
Night Effect - Changing ionosphere behaviour.
Synchronous Transmission - Two separate signals interfering.
Bank - When turning due to the movement of the coils over the EM wave.
Coastal Refraction - Will be along the coast.
Quadrantal - Electrical field along longitudinal axis of a/c
103
What does VOR stand for?
VHF Omnidirectional Range
104
How many signals does a VOR transmit?
2
Omnidirectional + Rotating
105
Describe the 2 signals that a VOR transmits.
Omnidirectional REFERENCE signal (30 Hz)
Rotating DIRECTIONAL signal (30 Hz, 1800RPM)
106
What physics concept does a VOR take advantage of in order to determine bearing?
Phase difference between 2 EM signals
107
The VOR transmits the Omnidirectional signal when the radial antenna is pointing _____.
NORTH
108
VOR uses what type of EM wave?
Space Wave (LOS)
109
How many reserved bandwidths are there for VOR and ILS?
3
110
VOR performance will depend on?
A/C altitude
Transmitter Power
Transmitter Height
111
How accurate do we say a VOR is?
+/- 1 deg
112
Ground Beacon error can be caused by:
Uneven terrain (valleys, hills etc), trees, buildings etc
113
When VOR radials deviate from their standard track due to terrain and start reflecting off of buildings, it is known as?
Scalloping
114
Describe VOR Interference and Ambiguity
Interference - Receive 2 signals from separate ground beacons.
Ambiguity - When the a/c converges on the VOR the radials tighten.
115
What does DME stand for?
Directional Measuring Equipment
116
In relation to a DME, what is the TRANSPONDER and what is the INTERROGATOR?
Transponder - Ground Beacon
Interrogator - A/C
117
The a/c transmits how many pulse pairs per second?
25 pulse pairs per second
118
The DME transponder alters the reply frequency by +/- 63 MHz to prevent _______ ________
Destructive Interference
119
What does protected range and altitude mean?
The range and altitude outside which signals of the same frequency may have originated from a different transmitter.
120
What does TACAN stand for?
TACtical Air Navigation
121
TACAN is the Military equivalent of _____
VOR/DME
122
TACAN is ____ accurate than civilian ______
MORE accurate than civilian VOR/DME
123
In a TACAN, the DME operates in the UHF band, with every UHF frequency paired with _______
a VHF band frequency.
124
A TACAN can be co-located with a VOR. This is known as ____
VORTAC
125
In a TACAN, the Omnidirectional pulse fires when the directional pulse is pointing _____
EAST
126
TACAN has ___ channels.
Each channel is number _ to ___ with each having an _ or _ designation.
252 channels
Number 1 to 126, with X or Y.
127
What is the bearing accuracy of the TACAN?
+/- 0.5 deg
128
What frequency band does a DME operate on?
UHF
129
VOR determines _____
DME determines _____
VOR - DIRECTION
DME - RANGE
130
What does HSI stand for?
Horizontal Situation Indicator
131
The desired heading to a Beacon is set using the ___
CRS (Course)
132
List common inputs to the HSI.
Magnetic Heading
VOR/ILS
DME
TACAN
NDB
133
What does VOR stand for?
VHF Omnidirectional Range
134
What does TACAN stand for?
TACtical Air Navigation
135
What does ILS stand for?
Instrument Landing System
136
What does DME stand for?
Directional Measuring Equipment
137
What does NDB stand for?
Non-Directional Beacon (NDB)
138
In addition to the common nav inputs, what other information can be displayed on the HSI?
TCAS - Term. Coll Avoid Sys
INS - Inertial Nav Sys
IRS - Inertial Ref Sys
Radios
Special purpose - Threat warning, Weather, moving map, A2A radar.
139
What does LLZ stand for? (in relation to ILS)
Localiser
140
What does GP stand for? (in relation to ILS)
Glidepath
141
What does an ILS enable?
Runway approach under instrument flight conditions.
142
The right lobe of the LLZ (Localiser) is amplitude modulated by how much?
150Hz
143
The left lobe of the LLZ (Localiser) is amplitude modulated by how much?
90Hz
144
As you drift from centreline, the _____ of a LLZ (localiser) lobe increases.
STRENGTH
145
If you approach from right of centreline the aircraft will receive more of the ____ Hz signal.
150Hz
146
If you approach from left of centreline the aircraft will receive more of the ____ Hz signal.
90Hz
147
The LLZ (localiser) operates in HF/VHF/UHF band? (Choose one)
VHF
148
The glidepath transmitter operates in the HF/VHF/UHF band? (Choose one)
UHF
149
The localiser (LLZ) modulates signal in the _________ direction.
HORIZONTAL
150
The glidepath(GP) transmitter modulates signal in the _________ direction.
VERTICAL
151
The UPPER LOBE of the glidepath signal is modulated at ___ Hz.
90Hz
152
The LOWER LOBE of the glidepath signal is modulated at ___ Hz.
150 Hz
153
If you are receiving more of the 90 Hz modulated signal, you are ____ the glidepath.
ABOVE
154
If you are receiving more of the 150 Hz modulated signal, you are ____ the glidepath.
BELOW
155
Aircraft using ILS can fall into one of how many ILS Operational Performance categories?
5
156
Information about the specific associated with glideslope can be found in the __ ____
UK AIP
157
Name the 5 ILS Operational Performance categories.
Category I
Category II
Category IIIA
Category IIIB
Category IIIC
158
What is the Decision height and Runway Visual Range (RVR) limits of an ILS Category I a/c?
DH - Not below 200ft.
RVR - Not less than 550m.
159
What is the Decision height and Runway Visual Range (RVR) limits of an ILS Category II a/c?
DH - Not below 100ft.
RVR - Not less than 300m.
160
What is the Decision height and Runway Visual Range (RVR) limits of an ILS Category IIIA a/c?
DH - With dual autopilot; Not below 50ft.
RVR - Not less than 200m.
161
What is the Decision height and Runway Visual Range (RVR) limits of an ILS Category IIIB a/c?
DH - With dual autopilot; Lower than 50 ft or no DH.
RVR - Not less than 75m.
162
What is the Decision height and Runway Visual Range (RVR) limits of an ILS Category IIIC a/c?
DH - With dual autopilot; No DH limits. Guidance to and along runway & taxiways.
RVR - No external visual reference.
163
List some ILS errors
Scalloping - Rapidly oscillating indications.
Beam bend - Gentle curve of the approach path.
FM Transmission - Frequencies just below 108MHz can produce spillage into LLZ frequencies causing interference.
Weather - Heavy snow or rain may attenuate ILS signals. Reducing range and degrading accuracy.
164
What does MFD stand for?
Multi-Function Display
165
What does EFIS stand for?
Electronic Flight Information System
166
List the key components of EFIS
ADS (Air Data System)
ADC (Air Data Computer)
AHRS (Attitude and Heading Reference System)
EICAS (Engine Indicating and Crew Alerting System) or ECAM (Engine Central Aircraft Monitor)
Integrated Avionics Unit
Data Bus
PFDs (Primary Flight Displays)
MFDs (Multi-Functions Displays)
IESI (Integrated Electronic Standby Instrument)
167
What does AHRS stand for?
Attitude and Heading Reference System
168
What does ADAHRS stand for?
Air Data Attitude and Heading Reference System
169
What does EICAS stand for?
Engine Indicating and Crew Alerting System
170
Why might you need to be careful when reading fuel flow to the engines on MFDs?
The display may be presenting individual feeds if you have separate engines. Summing of flows needs to be done to determine total flow.
171
The data bus contains what? (List L to R with respect to the diagram in notes)
Bus Controller
3 x Remote Terminal
Bus Monitor
172
The two main types of display are
MFDs and PFDs
173
A total failure of display will be indicated by a _______
BLANK SCREEN
174
Failure of the feed to the display will be indicated by ______
RED CROSSES (X)
175
The MFD can display various information. This can be …
Airspace Info
Charts
Airways
TCAS
176
MIL_STD-……. is the high speed data bus network used to connect equipment.
MIL-STD-1773
177
What piece of equipment is known as the “Heart of processing” and processes all the data from the a/c’s avionics and formats it.
Integrated Avionics Unit
178
What does INS stand for?
Inertial Navigation System
179
What does GPS stand for?
Global Positioning System
180
An INS uses accelerometers and gyros to determine and track ____, ____ and ___.
POSITION
ORIENTATION
and
VELOCITY
181
List the components of the INS (5)
Frame mounted Gimbals and motors
Accelerometers and Gyros on a gyro-stabilised platform
A computer
Aircrew interface
Cockpit displays
182
INS gyros are contained in a ____ ______ unit
FLUID FILLED
183
How many Gyros do you need to cover ROLL, PITCH and YAW?
3
184
Gyros are used in an INS for what purpose?
Keep the platform holding the accelerometers stable
185
The integrator is used to convert acceleration to _____
VELOCITY
186
The FIRST stage of the alignment process of the INS is ______
HEATING
187
What is the rate of INS heating during warmup?
15degC/min
188
During INS heating the operating temp is about _____
70degC
189
What are the two kinds of levelling done to an INS?
Fine
Coarse
190
The gyro compassing during alignment of the iNS aligns the platform with ____ ______
TRUE NORTH
191
The E-W gyro detects the _____ ________
EARTHS ROTATION
192
Once the - gyro reads zero azimuth gimbal is stopped.
E-W
This is when the Earth’s rotation has no component affecting the platform.
193
Once aligned a _____ ‘____’ light is illuminated
GREEN ‘READY’
194
Strapdown INS/IRS systems are typically c_____, more r_____ and more r_____ than gimballed systems.
CHEAPER
more RELIABLE
more RUGGED
195
Maximum error in SCHULER tuning occurs at __._ minutes and __._ minutes following disturbance.
1 mins
63. 3 mins
196
Some INS errors are
Gimbal lock (Gimballed system)
- Compounding of disturbances from turbulence or vibration
197
Name the 3 SEGMENTS associated with GPS
SPACE
CONTROL
USER
198
GPS satellites are in the ___ segment
SPACE
199
GPS sats transmit on what 2 frequencies?
L1 - 1575.42 MHz
L2 - 1227.6 MHz
200
C/A code is transmitted on what freq(s)?
L1
201
P code is transmitted on what freq(s)?
L1 and L2
202
The 2 services available from GPS are ____ and ____
SPS - Standard Positioning Service
PPS - Precise Positioning Service
203
What GPS service will provide you with the most accurate service?
PPS - Precise Positioning Service
204
PPS is primarily intended for …..
Military Users
US, NATO and AUS
205
What does GNSS stand for?
Global Navigation Satellite System
206
List types of GPS receiver
Continuous tracking
Sequential
Multiplex
All-in view
207
List some GPS errors
Insufficient satellite availability
Ionospheric Effect
External interference and masking - LOS
Multipath effects (signal reflection from buildings)
208
Describe Differential GPS
The use of a ground station to minimise GPS errors.
209
When utilising Differential GPS; corrections are applied to the GPS signal at the ____ receiver.
USER’S
210
What does GNSS stand for?
Global Navigation Satellite System
