Aircraft navigation systems provides to the crew the data required to flight for with in most appropriate safety requirement
These data divided in to 4 groups
• Airdata / Inertial reference system
• Landing and taxi aids
• Independent position determining
• Dependent position determining Radio Navigation control
Automatic tuning
• FMGC controls tuning of VOR, DME, ILS and ADF through RMP (RMP is transparent, system operates even RMPs Sw. OFF)
• In normal operation FMGC 1 controls each system receivers 1 and FMGC 2 controls receivers 2
• Abnormal operation, failure of FMGC 1or 2, remaining FMGC controls all receivers USING MCDU
• MCDU display on RAD/NAV page information coming from FMGC are indicated in small fonts
• Manually entered data indicated in big fonts
• Manual tuning
• Permits to crew to select through MCDU required frequencies to display on EFIS
• To returned to auto tuning mode the manual tuning has to be cleared
(Write “CLR” on scratch pad by pressing CLR P/B then press line key next to the line to be cleared) Back up tuning
• RMPs provides back up to radio navigation tuning, if both FMGC failed or Emergency generator powered
• ILS course and frequency are the only data exchanged. Selected values on RMP 1 or RMP 2 are same for ILS 1 & 2
Tuning using RMP
• Select NAV Sw. (Green Lt. ON)
• Select required P/B to be tuned (VOR,ILS …)
• Tune required frequency on the STBY/CRS window and press transfer Sw.
• Select required course on same window
• Press transfer key to prepare window for another setting
RMP
• STBY operation is used for navigation in case of dual FMGC failure provided NAV P/B pressed IN
• ON /OFF Sw. – Controls RMP power supply
• NAV Sw pressed - Only performed after dual FMGC failed, use as a back up (RAD/NAV selection) - If no any other STBY NAV Sw. pressed, displays shows communication frequencies
- On MCDU RAD/NAV page inhibited
ACTIVE STBY/ CRS
STBY NAV ON
OFF
VHF1 VHF2
HF 1
NAV
VHF3
HF 2 AM
VOR ILS MLS ADF BFO
• SEL Lt. – Illuminates when other RMU select own side selection (VHF 1 selected by RMP 1 or 3)
• VOR, ILS, ADF press (one at a time) – Changes display to last RMP memorized values (Freq. Course or Runway heading)
- Any time communication freq. Still selectable by pressing corresponding key
• BFO – Can be set by pressing the key to listen Morse code of station identification
• STBY / CRS window – If course displayed, associated frequency will be displayed in the active window
- If cause displayed in STBY/CRS window, by pressing transfer key active frequency will display in both windows (to provide next frequency selection)
• Active window – Shows the frequency in the system identified by the Green LED in selected key MCDU
• Allows to display the radio navigation frequencies (automatically or manually) on specific page called RAD / NAV
• Align IRS from page INIT via FMGC
• Initiates test for all navigation systems and T/S via CFDS ACP
• Enable to control all radio reception signals
• DME identification signal can be selected by using knob of collocated VOR or ILS Standby Instruments
• Standby compass
• Located in windshield center post, in normal configuration stowed and correction card glued to side of the compass assembly
• Standby Horizon
• Flag in view
• Electrical failure
• Gyro speed drops below 18000 rpm
• Fast resetting can be done by pulling caging knob
• Standby Altimeter
• Qty 4 bug to set reference altitude setting
• Internal vibrator only operative in flight
• Baro correction displayed in hecto pascals
• Standby Airspeed indicator
• Qty. 4 manually adjusted bugs to set reference speed
• DDRMI
• Combine VOR/DME RMI
• L/H display – DME 1
• R/H display – DME 2
• Single pointer – VOR 1 bearing
• Double pointer – VOR 2 bearing
• DME display goes to blank if failure detected and dashes with NCD(out of range station)
• Heading failure will be indicated by Red HDG flag (comes from ADIRU 1or 3 if ADIRU 1 fails)
• VOR failure will be indicated by Red VOR flag and corresponding pointer goes to 3 O’clock position
• VOR NCD will be indicated by corresponding pointer goes to 3 O’clock position but no flag
• Receiving information from ADIRU 1 & 3
Air data Reference and Inertial Reference Systems (ADIRS)
• Consist of Qty. 3 ADIRUs and own set of probes and sensors + common CDU
• Airdata and Inertial reference both located in one unit called ADIRU
• Air date reference system
• Each ADR receives other 2 ADR inputs to cross check
• Mainly computes Speed and attitude information from air parameters
• AOA sensors 1,2 & 3 connected to ADR 1,2 & 3
• TAT 1 connected to ADR 1 & 3 and TAT 2 connected to ADR 2, each sensor consist of two sensing elements. On TAT 2, 2nd sensor does not used
• Provides barometric altitude to ATC for mode “S”
• Data for FAC for various characteristic speeds
• Data for WXR for antenna stabilization
• Inertial reference system
• Mainly computes Heading, Attitude and Position from Laser gyros and Accelerometers
• Normally each IR receives 3 ADR inputs, but own ADR input used to IR data computations
• Provides true heading when
• Above 82° north
• Above 73° north between 90° and 120° west (magnetic polar heading)
• Above 60° south
• ADIRU switching control
• Each IR unit consist of two discrete inputs called Auto and Manual
• On IR 1 and 2 Auto inputs are permanently grounded, On IR 3 both inputs connected to “ATT HDG”
and “AIR DATA” transfer Sws. for selection.
• IRs selects inputs from other ADRs as per ground provided on auto or manual inputs as per switching selection
Auto Manual
ADR bus selected by IR according to its pin
programming Ground Ground or Open First from int ernal bus,
then Bus “A”(if int. bus fails) then Bus “B” (if bus “A” fails)
Open Open Bus “A”
Open Ground Bus “B”
• Air data module (ADM)
• Total Qty 8
• Captain’s side
• Qty 1 for Pitot and 2 for Static
• FO’S side
• Qty 1 for Pitot and 2 for Static
• STBY
• Qty 1 each for Pitot and Static
• Receives one pressure and several discrete signals
• Discrete inputs determines ADM location and type of air data to provide to the ADR
• Out put is digital ARINC bus ADIRU display unit
• Can be used as a back up for ADIRU alignment
• Checks ADR operation ADR
Push button press – OFF LT. ON
- Related ADR out put buses will be disconnected
Fault Lt. ON – ADR failure
NAV NAV – Normal mode of operation provided full inertial data in the system OFF ATT ATT – System still energized but IR down graded
- Magnetic HDG to be entered keyboard and update frequently - Back up mode of operation if NAV mode lose provides only attitude and Heading information
IR FAULT
OFF
IR Fault Lt. ON – IR fault
Steady Lt. – Respective IR lost
Flashing – Attitude and heading information can be recovered by selecting to ATT
Align Lt. ON – During alignment phase - Lt. flashing
- Alignment error
- P. Pos not entered with in 10 min of NAV selection - Difference in 1° P.Pos at last shut down and entered
• PPOS – Present latitude and longitude displayed
• WIND – True wind direction and wind speed displayed
• HDG. – True heading and TTN – time to Nav. Gives remaining time to complete alignment
• STS – System and maintenance messages displayed (maintenance and action codes)
• DMC 1 receives data from ADIRU 1 & 3
• DMC 2 receives data from ADIRU 2 & 3
• DMC 3 receives data from all 3 ADIRUs
• ADIRU 1 for Capt’s instruments and ADIRU 2 for FO’s and ADIRU 3 for STBY
• ADIRU 2 send TAT and SAT to ECAM system page, If ADR 2 fails ADR 3 provides as a backup after manual selection
Manual Switching
• Mainly for recover displays Automatic Switching
• If one ADR 1 or 2 fails ADR 3 automatically transfer to ADR 1 or 2 for internal computations only. Not for display purpose
Control panel operation
• When select NAV Sw. wait until “ON BAT” Lt. disappear after each selection
• If ADIRU comes from shop need to enter P. Position two times as ADIRU compares last P. Position and last position
AUIRU power supply
Normal Bus Emergency Bus
AC DC AC ESS DC ESS HOT
ADIRU indications
• Local warnings on PFD and ND will be created by DMCs (eg. Flags…..)
• ECAM ADIRU warnings and cautions monitored by FWC PFD indication
Attitude
• Pitch
• Shows pitch angle on a scale
• Pitch angle more than 25° or -13°, guidance symbol and FMA will removed
• Roll
• Comprises roll graduations 0° to 67°, roll angle > 45° guidance symbol and FMA will removed
• Roll index
• Moves with roll scale and provides roll angle
• Flight path vector
• Indicates actual A/C inertial trajectory
• Used as a reference when FD is engaged in Track / flight path (TRK/FPA) angle mode
• FPV – Created by IRs and FPD – created by FMGCs
• Discrepancy
• Discrepancy detected between captain’s and FO’s Amber “CHEK ATT” will be displayed on both ATT displays (Threshold - 5°)
• Detection compared by 2 IRs in use with in the FWC
• Failure
• Will be displayed by Red “ATT” flag
• Flag flashes then steady
• Detection compared by 2 IRs in use Heading
• Magnetic heading will be displayed on lower part of PFD (Scale 5° between graduations)and white line on horizon (Scale 10° between graduations)
• Lower scale yellow line shows fixed heading reference
• Green diamond shape symbol indicated actual track
• TRU will indicates when true heading indicates instead of magnetic heading (Used Lat. > 73° north and 60° south)
Discrepancy
• Discrepancy detected between captain’s and FO’s Amber “CHEK HDG” will be displayed on both HDG displays (Threshold - 5°)
• Detection compared by 2 IRs in use with in the FWC
• Failure
• Will be displayed by Red “HDG” flag and all graduations will be diapered on the scales
• Flag flashes then steady
• Detection by associated ADIRU Airspeed
• Displayed on L/H side of the PFD (Computed Air speed)
• Display starts from 30 Kts, bellow 30 Kts set to NCD, Range 30 to 520 Kts
• Yellow fixed reference line shows actual airspeed on the scale
• Mach number displayed speed > 0.5 M and no ILS selection, disappeared at o.45 M Failures
• Will be replaced by Red “SPD” flag, if Mach number failure number will be replaced by RED “MACH” flag Vertical speed
• Displayed on the R/H side of the PFD, graduation Feet per min.
• Green pointer shows VS in analogue form
• Above threshold numerical valve in hundred of feet comes in to view
• Displayed
• V/S > 200 Ft/MN or V/S < -200 Ft/MN
• Excessive speed causes both indications amber
• Inertial V/S not avail Baro V/S will indicate
• Amber box surrounds the numerical value 7
Failures
• Red “V/S” flag appears if total indication failure Altitude
• Displayed on the R/H side of the PFD
• A/C altitude indicated on window counter hundred of feet and drum tens and units
• Baro reference STD,QNH or QFE according to the selection on the panel
• Knob
• Pull – STD selection
• Push once – QNH
• Puss twice - QFE Discrepancies
• Discrepancy detected between captain’s and FO’s Amber “CHEK ALT” will be displayed on both ALT displays (Threshold - 250 ft if baro selection QNH or QFE, 500 ft if STD selected)
• Detection compared by 2 IRs in use with in the FWC
• Failure
• Will be displayed by Red “ALT” flag
• Flag flashes then steady
• Detection by associated ADIRU N/D indications
ROSE Mode
• Displayed 360° around fixed A/C symbol
• Speed indication shows on the left upper corner
• GS – Ground Speed – Computed by IR
• TAS – True Air Speed, computed by ADR, both goes to dashes if NCD, - Displayed only if speed > 100 Kts
• Wind shows in Green L/H upper corner
• Origin in degrees with respect to the true north
• Wind force in Kts displayed if speed > 2 Kts
• Arrow shows direction with respect to the A/C heading, displayed if speed > 2 Kts
• Shows dashes if NCD Heading
• Fixed lubber line with rotating compass rose
• If indication is True heading TRU shows Discrepancies
• Discrepancy detected between captain’s and FO’s Amber “CHEK HDG” will be displayed (Threshold - 5°)
• Detection compared by 2 IRs in use with in the FWC
• Failure
• Will be displayed by Red “HDG” flag
• Flag flashes then steady
• Detection compared by 2 IRs
ARC Mode ( Rose Nav mode indication same as Arc mode except it displays 360° full range )
• Display 90° sector ahead of the A/C
• Information comes from FMGC
• WXR indication possible
• Speed indication shows on the left upper corner
• GS – Ground Speed – Computed by IR
• TAS – True Air Speed, computed by ADR, both goes to dashes if NCD, - Displayed only if speed > 100 Kts
• Wind shows in Green L/H upper corner
• Origin in degrees with respect to the true north
• Wind force in Kts displayed if speed > 2 Kts
• Arrow shows direction with respect to the A/C heading, displayed if speed > 2 Kts
• Shows dashes if NCD
Heading
• Fixed lubber line with 90° arc
• If indication is True heading TRU shows Discrepancies
• Discrepancy detected between captain’s and FO’s Amber “CHEK HDG” will be displayed (Threshold - 5°)
• Detection compared by 2 IRs in use with in the FWC
• Failure
• Will be displayed by Red “HDG” flag
• Flag flashes then steady
• Detection compared by 2 IRs PLAN Mode
• Information comes from FMGC
• Displayed active and other way points as per the flight plan after action on the MCDU
• WXR display not possible
• Reference to the True heading
• Speed indication shows on the left upper corner
• GS – Ground Speed – Computed by IR
• TAS – True Air Speed, computed by ADR, both goes to dashes if NCD, - Displayed only if speed > 100 Kts
• Wind shows in Green L/H upper corner
• Origin in degrees with respect to the true north
• Wind force in Kts displayed if speed > 2 Kts
• Arrow shows direction with respect to the A/C heading, displayed if speed > 2 Kts
• Shows dashes if NCD Warning Messages
• Although ADIRU ECAM warning messages are Amber, Directly comes from FWC
• ADR 3 or IR 3 failed during active fault Lt. will be shown, but if failure happens during emergency configuration ADR 3 or IR 3 fault warning will be inhibited
• Over speed ( M/W + CRC)
• VMO/MMO – Clean configuration, speed > VMO + 4Kts / MMO + 0.06
• VLE – Speed > VLE + 4Kts with L/G not up locked or L/G not closed
• VFE – Speed > VFE + 4Kts with slats and / or Flaps extended
• Stall (M/W + CRICKET+ synthetic voice)
• AOA test only on Gnd., During test all aural warnings will be available Landing and Taxing aids
• Head up displays
• Piloting aids system for rollout, take off and landing
ILS • Used to obtain optimum A/C position during approach and landing
• Allow A/C to follow the optimum descend
• LOC and G/S beams created by Gnd. station at known frequencies
• Components are Qty 2
• Antennas – Qty. 1 LOC and G/S common for both receivers
• Receivers – Can be tested by P/B on the face and LED for indications
• System connected to
• PFD and ND for display
• EFIS for display control
• FMGC for auto tuning
• MCDU for manual tuning
• RMP for back up tuning
• ACP for ILS audio signal Indicating
• ILS display indicated in Magenta
• ILS 1 information will displayed on PFD 1 and ND 2 (For monitoring and comparing)
• ILS 2 information will displayed on PFD 2 and ND 1 (For monitoring and comparing) On PFDs
• As soon as EFIS PFD control panel ILS P/B pressed IN
• Displays a the bottom L/H corner
• Station ident –
• LOC and G/S valid
• ILS ident valid
• Frequency valid
• LOC and G/S valid
• DME distance
• When ILS/DME available
• ILS indication flashes when ILS display not selected in approach mode
• If excessive deviation, ILS scale and vertical/lateral index will flash
• Flags
• Red “ILS” flag will indicated if both G/S and LOC both signals failed at the L/H bottom corner + Red “LOC” & “G/S” flags
On NDs
• As soon as the EFIS control panel mode Sw. selected to ILS
• All the ILS indications displayed on Rose ILS mode
• If ILS P/B selected and Mode Sw. selects NAV or ARC on EFIS control panel, ILS course pointer will be indicated on NAV and ARC modes
• On Rose ILS mode
• Top R/H corner
• Selected ILS
• ILS frequency
• ILS course
• Station identification
• If excessive deviation, ILS scale and vertical/lateral index will flash or
• Course pointer indicated when ILS course selected by
• FMGC (automatically or manually)
• RMP (backup)
• LOC deviation bar not shown if NCD
• Flags
• Red “ILS” flag will indicated if both G/S and LOC both signals failed
• If ILS failure course pointer be comes Red + points to 12 O’clock and lateral bar will remove Auto tuning
• FMGS automatically tunes own side ILS receiver through own side RMP (RMP transparent)
• If one FMGC failed discrete switching signal switches tuning port to connect other FMGC directly to ILS receiver bypassing RMP
Manual tuning
• MCDUs can tune own side ILS receivers through own side FMGCs
• To return to auto tune mode manual mode to be cleared Backup tuning
• If both FMGCs failed backup tuning can be performed by RMPs
• Either RMP tunes both ILS if NAV mode selected on RMP 1 and 2
• RMP 3 not connected to the navaids tuning
• During emergency electrical configuration only RMP 1 is supplied LGCIU
• sends FLT/GND information to count flight legs ILS data sends to
• FMGCs to A.C guidance during T/O, Approach and landings
• Sends to FWC for ECAM warnings
• ILS 1 send to GPWS for mode 5 computation (descend bellow G/S)
• Discrete signal sends to FMGCs to inhibit frequency changes in ILS receiver when land mode < 700 ft
• CFDIU to T/S and testing only on Gnd.
Multi Mode Receiver System
• Combination of ILS and GPS
• Components used
• Qty. 2 ILS antennas
• Qty. 2 GPS antennas
• Qty 2 MMR units
• System connected to
• PFD and ND for display
• EFIS for display control
• FMGC for ILS auto tuning and GPS position
• MCDU for ILS manual tuning
• RMPs for ILS backup tuning
• ACP for ILS audio signal
• ADIRU for GPIR data
• GPS indicating
• Data indicating on MCDU (GPS monitor page)
• GPS position leg
• True track
• GPS altitude
• Figure of merit
• Ground speed
• Number of satellite tracks
• Mode
• NDs
• Availability of GPS primary navigation function Auto tuning
• FMGS automatically tunes own side MMR receiver through own side RMP
• If FMGC failed discrete switching signal switch tuning port to connect other FMGC directly bypassing RMP
Manual tuning
• MCDUs can tune own side MMR receivers through own side FMGCs Backup tuning
• If both FMGCs failed backup tuning can be performed by RMPs
• Either RMP tunes both MMR if NAV mode selected on RMP 1 and 2
• RMP 3 not connected to the navaids tuning
• During emergency electrical configuration only RMP 1 is supplied Antennas
• G/S and LOC antennas common to both receivers GPS primary function
• Tracks the RF signals from satellite and computes its own position and output the GPS data to 3 ADIRUs
• GPS three dimensional A/C position, velocities and exact time used by hybrid computation by 3 ADIRUs
• If one GPS failure, ADIRU automatically selects operative GPS to hybrid GPIR data
• To reduce initialization time MMRs receive position data, time and date from own ADIRUs
• As long as GPS/IRS mode is active, radio updating DME/DME or VOR/DME is not allowed
• FMGCs to A.C guidance during T/O, Approach and landings
• Sends to FWC to ECAM warnings
• MMR 1 send to GPWS for mode 5 computation
• Discrete signal sends to FMGCs to inhibit frequency changes in MMR receiver when land mode < 700 ft
• CFDIU to T/S and testing only on Gnd.
Independent position detection system
• Detection with out taking any ground station information
• Weather radar – WXR indication shown on N/D
• Radio altimeters – Provides A/C height with out independent of atmospheric pressure
• TCAS – Detects A/C in vicinity immediately
• GPWS – Warns to crew about the A/C behavior Weather Radar System
• Contains
• Antenna – Controls in azimuth and elevation by the transceiver, scans 180° in azimuth and +/- 15° in Tilt, movement at 2 DC motors and angle detected by synchros
• Wave guide – Radio frequency signals exchange between transceiver and antenna
• Transceiver Unit – Operates in “X – band” frequencies and digitizers video signal for display on the ND, test can be done on the face test Sw. and indicator Lts.
• Control Unit
• ON / OFF Sw. – System energized and operates provided selection in Rose or Arc mode
• Gain knob – Allows to set the gain as required. In auto selection optimum setting automatically
• Gain knob – Allows to set the gain as required. In auto selection optimum setting automatically