ATA 34 – NAVIGATION
- Air Data/Inertial Reference System (ADIRS)
- Landing and taxing aids
- Independent position determining
- Dependent position determining
ADIRS
- 3 Air Data/Inertial Reference Units (ADIRU) > ADIRU 1, ADIRU 2, ADIRU 3.
- Air data function through its Air Data Reference (ADR) portion.
- Attitude, heading and position function through its Inertial Reference (IR) portion.
- Standby systems
- ISIS
- ISIS indicator replaces 3 conventional standby instruments –
- Standby altimeter
- Standby airspeed indicator
- Standby horizon indicator
- Standby Compass – for standby heading ……… (independent instrument)
- ISIS
Landing and Taxiing Aids
- Paravisual Indicator (PVI) (optional system)
- Head Up Display (HUD) (optional system)
- Instrument Landing System (ILS) (optional system) >>> MMR
- The primary function of the Multi-Mode Receiver (MMR) is to receive and process Instrument Landing System (ILS) and Global Positioning System (GPS) signals.
- The MMR also receives the approach data from the Global Navigation Satellite System (GNSS) Landing System (GLS) function.
- The MMR is a navigation sensor with two internal receivers – ILS receiver & GPS receiver. >> (ILS receiver – Localizer and Glide/slope).
- 2 MMRs – MMR1 and MMR2, linked to:
- Localizer and Glide/slope antenna
- GPS antenna
Independent Position Determining
- Weather Radar (WXR) system
- Radio Altimeter (RA)
- TAWS – Generic Term
- Ground Proximity Warning System (GPWS)
- EGPWS
- TACS – Generic Term
- Traffic Alert and Collision Avoidance System (TCAS)
- Traffic and Terrain Collision Avoidance System (T2CAS)
- Traffic and Terrain Collision Avoidance System (T3CAS)
Dependent Position Determining
- Distance Measuring Equipment (DME)
- Air Traffic Control (ATC)
- Automatic Direction Finder (ADF)
- VHF Omni-Range (VOR)
- Global Positioning System (GPS) (optional system)
Training Note
- Why pitot/static port both side (cross connection) – to minimize error.
- Static – position error
- Total 8 ADM – all are interchangeable
- Pitot – 3
- Static – 6
- Pitot probe – total pressure
- ISIS – direct connection to port not through ADM
- Source – pitot – stby pitot probe / static – stby static probe
- Laser gyro – total 3 – inside ADIRU (IR part).
- 2 beam in each gyro – beam travel time
- Error signal in terms of frequency
- Frequency is inversely proportional to time.
- IR inside
- 1 ring laser gyro for each axis
- 1 accelerometer for each axis
- There is a separate 3 axis accelerometer for FDR. (do not confuse with accelerometer inside IR)
- Water drain in stby static port – because direct source for ISIS.
- Mode selector unit (MSU) of ADIRS (- ADIRS MODE)
- NAV
- ATT – only heading
- ISIS
- ATT/SPEED/ALT – Same place as in PFD.
- BUGS + LS – press for at least 2 sec. >> maintenance mode.
- LS – press to avail localizer and glidescope.
- BUGS – for BUGS setting. Press bugs only.
- Red flag – if system is inop. (eg. ATT , HDG in red)
- Mean sea level – for altitude calculation
- QNH – sea level atmospheric pressure
- In NEO only – ISIS test can be done through MCDU.
- GPS – 360 degree – divided into 6 >> each 60 degree
- When GPS is active – no VOR/DME/ADF is required.
- VOR/DME – single unit
- All DME are installed with VOR at ground >> VOR + DME – all VOR station
- If tune VOR – automatically tune DME, frequency are paired and installed at ground together.
- VOR/DME on ND
- VOR 2 – VOR sys 2
- VIDP – Airport
- 34 NM – given by DME
- Minimum 4 satellite – GPS position (normally 6 are available)
- MMR – 90 VU
- ILS 1 – PFD 1 & ND 2
- ILS 2 – PFD 2 & ND 1
- GPS is primary navigation now.
- GPS Monitor Page on MCDU
- MERIT – 100 >> GPS accuracy is up to 100 meter
- mode/set
- NAV/6 – 6 satellite
- TRK – heading
- TAT 1 – only ADIRU 3. — stby
- ADIRU 1 — TAT 1.
- Normal
- MMR 1 – ADIRU 1, 3 – GPS 1
- MMR 2 – ADIRU 2 – GPS 2
- If ADIRU 2 fails –
- ADIRU 2 >> ADIRU 3
- Switch for GPS 2 input
- ATT heading selector knob switching (?)
- FMGC
- IR 1 & IR 2 – pure data – FMGC 1 & 2
- Pure GPS data – FMGC 1 & 2
- MMR > GPS data > ADIRU > FMGC
- Weather radar transmitter with predictive windshear system function in option.
- In old a/c – Map mode – map selection >>>> in WXR system
- Ground picture (antenna will tilt down)
- Now – EGPWS is doing the same function.
- PWS – 5 NM (class range) – takeoff/landing
- Precipitation rate –
- > 50 mm/hr – turbulence
- 12 – 50 mm/hr
- Windshear indication on ND – Red & Black + warning on PFD
- CAL knob – minimum position, use for testing.
- WXR antenna
- Holes for passing magnetic field
- Waveguide – hollow tube – less distance required for waveguide, that’s why separate self in 90 VU.
- Optical cable required less distance.
- Multiscan – top/down & left/right
- WXR related indication – ND only
- PWS related indication – ND + meaning (details) > on PFD
- Aft side of WXR antenna – BOARD – for protection from return waves.
- WXR stabilization signal from – ADIRU 1
- PWS
- below 2300 feet RA.
- Aural warning through – FWC (windshear ahead)
- If warning for the same time – PWS / TCAS & EGPWS >> PWS warning is inhibited.
- RA auto ON – no switch
- RTTR
- RA indication on PFD.
- Cooling fan – 2 for 2 RA transmitter
- TA / RA advisory
- 4 volume
- Indication on ND
- GPWS – database updated at every defined time.
- GPWS system has no antenna. It takes data from sources and computes.
- ELS >> ADS-B (is enhanced version) >>> ADS-B – IN/OUT
- Many Airlines have ADS-B — OUT only.