RNAV Flashcards
Frequency of VOR
112.1Mhz
ILS Frequency
109.3
Guidance in vertical and navigation in Horizontal
3D
ILS localised deviate beyond unacceptable limits, nav component will
Automatically be removed
Q code for beating from station to aircraft
QDR
Aircraft flown by autopilot, directed by FMS during coupled ILS app, FMS/Autopilot will
Continue descent through any FMS or pilot selected altitude restrictions to the MINIMUM APP ALTITUDE unless pilot MANUALLY intervene
Percentage of time for NAV performance to be met
95
Special position ident
Pressing ident button
Freq of radio wave
No. of radio waves cycles generated in one second (Hz)
Doppler VORs
Reduce VOR site errors
Comparing PSR and SSR
PSR requires more power
Bearing VDF gives at ground station when 2 aircrafts transmit simultaneously on same freq
Bearing proportional to the relative signal
Components of ILS
Localiser, Glidepath, Marker/DME
EHSI expanded VOR mode, what is the info displayed
W/V 103/20, HDG 130M
LAAS is … precisely sited at the Aerodrome which
Detects error and sends coordinate correction to aircraft
NDB failure
No visual warning
How does aircraft/DME station differentiate from signals from other aircrafts
Send irregular sequences of pulses that differential aircrafts
Given EHSI diagram (Exp VOR), what is the selected heading but and selected course
Heading 103M and Course selected 165M
When interrogated, Transponder reply
Coded signals
Some DME, as well as distance, provides
…
What is included in Performance Database for RNAV
Take off speeds, flight envelope, optimum altitude and speed etc
Mode S can respond to interrogation from Mode A and C, reason being? Of the following, which ground based VHF DF applications are still in use
ATC Identification, Aircraft Homing, Emergency Location Fixo
What determines Minimum Range
Pulse Length
Mode S needs to be compatible with Mode A and C. Why
Allows all aircraft to be used in Non-S mode areas
Map mode was shown on HSI with heading 060. VERDA VORTAC was shown on the map at roughly 030 to the left of AC. Qn asked what will be the heading to go to VERDA
030 as required
Response from transponder
Coded signal
Ground wave + sky waves
LF, MF
Inputs to a 4D RNAV system include the
Aircraft Heading from the Aircraft Inertial Reference System (AIRS)
Performance DB in FMS contains
Takeoff V speeds, thrust confit, flight envelope
GLONASS orbit height and inclination
19100km, 64.8degrees from equator
Difference between service area and coverage area
Service area determined by GROUND component, Coverage Area is determined by SATELLITE component
You are a distance away from VOR station and you notice your VOR needle if flucting left and right. What is a possible cause?
Terrain Effect
How does aircraft/DME station differentiate from signals from other aircraft
Pulse pair unique
Transponder transmit a reply
Coded Reply
FMC performance database includes
Similar options but include ENGINE CHARACTERISTICS, FUEL FLOW PARAMETERS and FLIGHT ENVELOPE DATA
Which of the following are transmitted by Sky wave and Surface Wave
LF and MF
Main components of SBAS
Space segment, ground segment, user segment
What does LAAS do
Uses GROUND site to measure ERRORS and pass coordinate information to aircraft
What is contained in aircraft navigational database
Aerodrome info, SID, STAR, runway dimensions, CAN BE CUSTOMISED for include company routes
What is modulation
Process of adding info to carrier wave
How does VDF determine aircraft position in emergency
At least 3 VDF stations providing bearing info to provide a fix: triangulation
What is contained in Aircraft performance database
Flight envelope data, Fuel flow parameters, engine characteristics
Polarisation of electromagnetic waves
Electric field
Enroute CDI deviation
2nm right of track
ILS marker with 400Hz tone
Outer marker
ILS marker with 1300Hz tone
Middle marker
Colour of ILS middle marker
Amber
SSR Mode A sequence of 4 digits that allows
4096 possible combinations
ILS course deviation bar on EFHI is magenta. What do you do?
Nothing. Course deviation bar is always magenta
Homing to NDB and magnetic heading increasing. Experiencing
Left drift
Track made good
Track you are currently on, depicted by WHITE ARROW on top
Range of AWR 40NM, peninsular detected - 180T 15000ft. Approximate range and relative bearing
15NM 230 degrees
Figure of DGI showing 275 degree
Figure of RBI showing 075 degree
Aircraft maintaining track of 280M, allowing for 5deg drift.
A new station is tuned and the ADF displays as indicated. Aircraft reaches new waypoint, where the station is at 010M, what will be the new relative heading?
095R
Q code for TRUE bearing from VOR
QTE
CGI shows 4 dot fly left indication.
If aircraft is 120NM away from VOR, how far off is it from the intended track?
16NM RIGHT of track
How does Mode S ensures unambiguous identification
Each aircraft has unique 24 bit address identification
Principal of ops of DME - The signal is sent at a frequency difference of
63mHz higher or lower than interrogation signal
How is Special Position Identifier (SPI) on SSR is used
To discriminate aircraft with same coding
Which equation represents range of VOR signal
R = 1.25 X sqrt(ht of aircraft) X sqrt(ht of transmitter)
Approx max number of aircraft that can use a DME beacon at any one time
100
If freq is halved, eg from 300 to 150, the wavelength,
Is doubled
Mode S allows exchange of info between
Ground to air, Air to ground, Air to Air
What function does ATC relies of primary radar
Traffic separation, Approach Guidance, Weather phenomenon identification
How Long should a dipole antenna be
Half of wavelength
A radial is obtained by VOR signal by
Comparing the phase of two 30Hz signals
Aircraft radio develops a fault that prevents any modulated transmission being encoded into the carrier wave. Aircraft radio can still be used for limited communication by pressing the transmit button in the series of Dots and Dashes. This process is referred to as
Keying
Range of radar can be increased by Super refraction. With radar Super refraction target will be visible
Beyond normal line of sight due to the downwards refraction of radio waves by refraction
Which frequency band does DME utilises
UHF
Electromagnetic radiation, aircraft current being passed through, electric field?
Electric field parallel to wire, Magnetic field perpendicular
RBI indicator: which shows the correct track
Shows aircraft on VOR radial of 180, but heading 170. Asked which is the correct indication of relative bearing. Choose the one pointing South and slightly left.
What is sensitive area
Where aircraft and vehicles movement are controlled to prevent interference during Low vis ops
What happens when localiser frequency drops to zero
Be indicated by the warning flag on HIS or similar instrument
Warning shown on flight deck when ILS is not received?
Warning flag on HIS or similar instrument/ILS receiver
Advantage of MLS
Terrain does not affect MLS
How does modern VHF DF determine bearing of aircraft
Using fixed loop and sense antenna similar to modern ADF
Marker freq of 400Hz
Outer marker
Marker freq of 3000Hz
Inner Marker
Marker freq of 1300Hz
Middle Marker
Colour of outer marker
Blue
NDB relative bearing from aircraft is zero. If the heading is increasing when aircraft flies, what type of drift is aircraft experiencing.
Left Drift
What does Locator NDB do
Low powered NDB used in airfield or runway approach procedures
Heading 60deg, Track 52 deg.
What will heading be if tracking to navaid which is 30deg from plane
38deg
What is coverage of localiser from 20NM
10deg of centreline
When using elementary surveillance, what is the ATS format being used
ICAO format
What is the propagation wave called when it is used to modulate and carry info with it?
Carrier Wave
Aircraft 24 bit mode S transponder code
Is hard coded into the aircraft at manufacture
In what way is Doppler radar better than conventional
Able to identify wind shear
If civil DME receiver is tuned to receive TACAN or VORTAC
Full DME info will be available to all civil DME stations
Rate of descent of 3deg glideslope, Groundspeed 145kts
725fpm
Which of the limitations apply to CAT II ILS
DH lower than 200ft but not lower than 100ft, RVR not less than 300m
Effect of coastal refraction on NDB signal
Cause aircraft to be nearer to the shore than actual position
When using a conventional VOR to track on VOR radial, influence of crosswind will
Required aircraft heading to be offset in the number of degrees required to maintain CDI in the centre
Night effect most pronounced at what timing
Dusk and Dawn
What will be displayed when radar CDU set to Wx + T
Weather and Turbulence
How differentiate transmit and reply of DME
Difference of 63MHz
DME determines Slant range by
Converting time offsets between transmission and reception signals to distance
VOR monitoring systems will detect failure in VOR station by measuring
Signal strength and any change in radials being broadcasted
Properties of NONA1A
When using NONA1A beacons, BFO should be selected ON for manual tuning, identification and monitoring
Function of airborne radar gain control
To adjust receiver sensitivity
In a FMS, which uses DME
FMS automatically corrects for slant errors
Doppler operates on the principle that the return signal from a radar pulse transmitted ahead of the aircraft will have
Increase in frequency directly proportional to aircraft ground speed
International Telco Union classifies radio waves with 3 symbols. First symbol indicates
Type of modulation of main carrier
A microwave landing system utilises
A time referenced scanning beam in the SHF band
VOR/Localiser receivers antennas are mounted on aircraft approx in a horizontal position. This indicates VOR/Localiser transmission
Are horizontally polarised
ADF accuracy is
Reduced at night due to the disappearance of the ionosphere D region
What does the bearing of the head of the needle indicate with a fixed card ADF
Relative bearing of aircraft from NDB
Aircraft heading 220M, RBI indicates 010, what is the magnetic bearing from NDB to aircraft?
050
Effect of coastal refraction can be reduced by
Taking bearing from NDB stations close to 90deg to coastline, as signal bends most from angles furthest away from perpendicular to the coastline
Max range to expect from VOR at Sea level and aircraft 6000ft AMSL
97NM
VOR frequency
112.9mHz
5 basic types of VOR in service, one of them
Doppler VOR
Commercial aircraft normally obtains DME signal by
Selecting appropriate paired VOR Frequency
Ground distance from DME station when aircraft is 33000ft and slant range of 7.5nm
5.2nm
Ground speed calculated by DME equipment most accurate when tracking
Directly towards or away from the ground station
Components of ILS that provides info in the vertical plane
Glidepath
Main disadvantage of SSR over PSR
Aircraft must carry and operate a transponder to be seen outside PSR coverage
SSR fruiting is
Interference at one interrogator caused by replies from a transponder to interrogations from one another
When ANT STAB is switched to on and aircraft radar control panel is selected to on, the antenna is stabilised with respect to
Horizon
Which of the following frequency used by SSR
1030mHz for interrogation for Mode A and C and 1090mHz for both responses
Airborne weather radar typically operates at which wavelength
3.2cm
Primary radar uses
Pulses of radio energy reflected from a target at same frequency
Nature of altitude info provided by Mode C
Altitude reported in 100ft increment
Q code for magnetic track from aircraft to home to VHF DF station
QDM
Thunderstorms
Causes ADF to behave erratically
DME comprises of
2 components - Aircraft interrogator and Ground Transponder
ILS glide slope freq
329.3mhz
Pulse recurrence frequency(PRF) for a radar system that is required to have a max range of 165NM
491pps
Area between max surface wave and first returning sky wave is
Dead space
Resultant VHF DF bearing if 2 ac transmit on the same freq simultaneously
VHF DF station not able to produce any bearing at all
When using ADF during hours of darkness, night effect is characterised by
Fluctuating bearings when further than 70NM from NDB
Night effect affects an NDB signal by
Limiting useful range at night to 70-80nm due to sky wave interference
VOR ident replaced by TST. This means
On test, may not be used
AC at FL350. Max range can receive VOR@450ft AMSL
256NM
Max error allowed for normal DME
0.25nm + 1.25%
Where is ILS localiser transmitter located
Far end of runway
Mode of interrogation used by Mode S for surveillance
Selective
What type of beam does AWR usually use
Pencil with a beam width of 3-5 deg
SSR ground interrogation signal’s P2 pulse is
Of diff amplitude from P1 and P3
Mode of interrogation by SSR ground station is determined by
Time interval between P1 and P3 pulses
Mode S ground station interrogation signals are transmitted as
P1, P3 and P4
Which reduces coastal refraction error
NDB near or at coast
NDB transmission distance affected by power. What is the relationship between distance and power
Power is squared function of increased range
Principle of DME
Pulse pairs
Continuous Wave technique
Adopts Doppler shift method
SSR locked up means
Selective Call
How many codes does 24bit Mode S transponder have
16000000
Mode A transponder, what does the controller see
Position and Code
DVOR is advantageous over CVOR because
Not affected by site errors
Incoming vertical polarised radio waves requires
Vertical Aerial
If frequency of radio wave is 480kHz, what is the wavelength
625m
Relationship between power and range
Inversely squared
What is required for efficient operation of radio antennas
Higher frequency, shorter Aerial
AC flying 6000ft, what is max theoretical range
97NM
Doppler principle
Used to create a signal received by the aircraft as a frequency modulated signal
ILS pic - Needle deflected right and Glideslope deflected down
Above Glidepath and left of centreline
Cessation of ident of ILS means
ILS unserviceable and procedure must be discontinued immediately
PRF of 500, what is the range
162NM
P2 pulse in SSR is used for
To suppress response from ac in the side lobes of the interrogation antenna
Most common type of modulation for carriage of info
Carrier Wave
How many beams minimum for full ILS
4
Radial 125, heading 265M and 5deg right, what does the instrument show FROM/TO and the course
FROM and 130
Moving target indicator - designed to eliminated returns from hills/buildings - how?
By jittering the PRF
What is the radar tilt formula?
Height(ft) = (TILT-BEAMWIDTH/2) C RANGE(nm) X 100ft
Properties of NONA1A
When using NONA1A, BFO should be selected on for manual tuning, identification and monitoring
Advantages of slotted antenna
Low power required, narrow beam and improved resolution
What is the required navigation performance for precision navigation?
RNP 1
RNP5 require a navigation performance accuracy of
+/- 5nm both lateral and longitudinal 95%of flying time
RNP may be specified for
Routes, an area, volume of airspace, or any airspace of defined dimensions
In 2D RNAV, how is the position fix obtained
Horizontal plane only
In 3D RNAV, how is position fixed obtained
Horizontal and vertical plane only
In 4D RNAV, how is position fix obtained?
Horizontal, Vertical and Time function
RNAV, pilot can
Change/insert waypoints throughout the flight, including waypoints that are not inserted on the start
How VOR/DME stations tune and identify when used with 2D RNAV system
RNAV system automatically tunes and identifies all selected stations
A 2D VOR/DME RNAV system
Will permit pilot to navigate without the need to fly directly over ground stations
What is the ICAO standard Colour for active waypoints displayed on EHSI
Magenta
How is position updating achieved with triple IRS twin FMC flight
Automatic position updating is carried out without pilot input
AWR when switched on, what is displayed on EHSI
Expanded VOR/ILS and Expanded Nav
In Plan mode, the projection is orientated to
True North
When using FMC during descent
It will descend the aircraft to the higher of the FMC selected altitude or pilot commanded altitude
When AC is flown by autopilot directed by FMS system during an ILS coupled approach, the FMS/autopilot will
Continue the descent through any FMS or pilot selected altitude restrictions to touchdown unless pilot manually intervene
When is DME used by FMC
During Kalman filtering process
Which one the following lists info given from basic RNAV system
Cross track distance, angular deviation
Which gives the best cross track indication
Flying abeam a VOR/DME station
FMS normally determines the aircraft gross mass by
Adding the fuel quantity indicating system fuel quantity to the previously entered ZFW
When is GPS used to determine FMC position
GPS data routinely used during Kalman’s filtering
For a basic 2D RNAV, what can be provided with a VOR/DME
Range distance from VOR/DME
How does an FMC normally determine the static outside air temperature in flight?
Temperature is obtained from ADC
Which options describes the navigational equipment for RNP in accordance with ICAO
INS, GNSS, DME/DME
How does FMS operate when in VNAV mode
Flight director/autopilot adjusts pitch to obtain climb speed
During climb in VNAV
Autopilot/Flight director controls speed to maintain climb speed
What does auto throttle and autopilot do to control climb
AT controls thrust and AP controls pitch to control climb speed
For RNAV level 2, DR is used
When you’re outside the DOC of all available VOR/DME
Level 2 DR (Dead Reckoning) system activates when
When no VOR/DME available
What is shown in modern 4D RNAV
Distance and time at current ground speed to any defined waypoint in the RNAV database
The aircraft has been cleared to its destination via a promulgated airway that is not along its standard route. How can this be entered into the CDU of the aircraft FMC
Pilot must enter each waypoint (lat&long) along the airway in the CDU
The displayed data in a modern FMS system
May be used in both NAV/HDG autopilot modes or when manually flying the aircraft
FMS uses sensors from
VOR, GME, ILS, GPS, IRS
Input to 4D RNAV system include the
AC heading from the AHRS (Aircraft heading reference system) - in LOs
FMC databases may be accessed by Pilots to
Read information only
Level 2 VOR/DME RNAV system allows pilot to
Allowed to change during flight
The CDU of a FMS equipped aircraft displays the following data ACT ECON CRZ. What is the current status of the VNAV
VNAV will only ensure the desired cruise level and target speed are maintained
2D RNAV system
Allows pilot to navigate without the need to directly fly over ground stations
Phantom waypoint: Where it should be located with respect to the VOR/DME designating it
Within Designated Operation Coverage of the VOR/DME
How are phantom waypoints created by 2D RNAV
Phantom waypoints are manually entered into the RNAV system by the pilot
Plane on autopilot and coupled with ILS
Autopilot controls everything
Wind velocity is sourced by modern FMS
Internally using ADC and IRS data
Which of the following components are normally included within a basic 2D RNAV system
CDU, Navigation computer unit, indicator (CDI/HSI)
Which is not an advantage of RNAV
Approach and landing without the need of ground equipment
Mach number is
Acquired solely from ADC
An AC is tracking towards a waypoint using 2D RNAV system with CDI set to linear en-route mode. How far off track is the aircraft
3NM right of track
How many GNSS are currently fully operational
- USA GPS, Russian GLONASS
What is the minimum number of GNSS satellites required for RAIM
At least 5
Which of the following GPS codes is transmitted on the L1 frequency
C/A and P code
What does SBAS correct for
Ephemeris, clock error, atmospheric error
What improvements does LAAS provide
Ephemeris, clock error and minimising atmospheric error
Which of the following correct identify SBAS with the region?
WAAS - USA
MSAS - Japan
GAGAN - India
EGNOS - Europe
Like the GNSS, the European Union Galileo system transmit continuous stream of navigation signal which consists of
Ranging code identifier and navigation message
Like the SBAS system, the EGNOS improves GNSS accuracy by?
Determines accuracy of GNSS data and send error signals to receiver
Principle of SBAS is to measure the
Accuracy of GNSS data and transmit satellite range errors to the GNSS user
The SBAS system can
Provide approach and landing ops with improved horizontal and vertical guidance only
Normal coverage of GBAS station
30km
What is corrected by using 2 frequencies in the GNSS system
Ionspheric delay
All GNSS are subject to influences that affect accuracy. A factor that can be almost eliminated by the use of 2 frequencies
Ionospheric Propogation Delay
How Long does it take for GPS data to download data frame
12.5minutes
Like the GNSS system, the GLONASS has the control segment, one function of the control segment is
Generation and uploading of Navigation Data
What is the working principle of GPS
3D position is obtained by measuring the relative time delay of signals from 4 or more satellites
Typical sensors in ABAS
Barometric altimeter, clock and inertial navigation systems
Unlike GBAS and SBAS, ABAS does not improve positioning accuracy
Link for ABAS to the qns of GNSS is that it uses RAIM
Frequency band does ICAO standard GBAS uses for data link
VHF (108-118kHz)
PRN (Pseudo Random Noise)
Code sequence repeating every milliseconds. C/A code is unique and provides mechanisms to identify each satellite
Freq of a GNSS that a civilian AC can use
L1 (1575.42Mhz - the higher freq) (C/A & P)
LAAS improves accuracy by
Correcting for coordinate errors
GBAS
Use Ground Control Link to improve on XYZ coordinates
How GBAS correct position
XYZ coordinate things
Difference between service area and coverage area with regards to SBAS
Ground reference stations determines service area, satellite based component determines coverage area
Diff btw coverage area and service area
Coverage area applicable to wide area system and service area applicable to local area system
When is satellite (SV) masked
Less than 5 degrees above horizon
What is the orbital height of GNSS
10898NM, 55deg, orbital period of 12 hours
What does the NAVSTAR/GPS constellation consist of
24 satellites, 55deg to equator
The GLONASS are in near circular orbit at
19100km, 64.5degrees to equator
3 segments of SBAS
Space, Ground/Control, User
Which of the following SBAS is correct
Geostationary Satellite Vehicles are used in order to broadcast message overa wide area
WAAS & other systems, are they compatible?
GPS, EGNOS &a GALILEO are compatible
Which of following statement regarding SBAS is correct
Full compatibility between all wide area differential GPS
Which statement is correct regarding local area DGPS
Provide failure warning, enhance GPS position removing ephemeris and SV clock areas and minimising ionospheric and tropospheric errors
The EGNOS Satellite Based Augmentation System (SBAS) is designed to improve accuracy to
1-2m horizontally, 3-5m vertically
2 modes of GPS that provides different standards of accuracy, the more accurate of these modes is only available
When the user is authorised for PPS service
GBAS transmits in VHF
True
US GPS has a master control station which is responsible for
All aspects of constellations command
GPS gives what fix and how many satellites
3D 4 satellites
