ATR 42/72-600 Systems Guide — Chapter P: Navigation System
Chapter P. NAVIGATION SYSTEM (FCOM DSC 34, 31)¶
Source: Direct transcription from ATR Systems Guide PNG pages 167–176 Pages 167–173: OCR extraction. Pages 174–176: manual transcription from PNG.
Page 167 — Section Divider¶
P. NAVIGATION SYSTEM FCOM DSC 34, 31
Page 168 — 1. NAV CONTROL, 2. MARKER SENSIBILITY SETTING, 3. ADF CONTROL¶
SYSTEMS 42/72 - 600
- NAV CONTROL MFD VOR/ILS ADF ND OVLY
ACTIVE 117.70 AUTO
ACTIVE 109.30 AUTO
V/ILS 1 117.70
V/ILS 2 < >
STBY 117.30 DME HOLD
STBY 114.45 DME HOLD
MCP ATA 34 VCP MCDU
NAV1 ACTIVE 114.05 DME HLD -> TEST STBY 114.05< PRESET>- NSA RSS IS
TUNE MODE AUTO/MAN< - C RETURN MENU FREQ NEXT CEME (FRLN DTO PERF
MCP and MCDU allow: - to tune VOR/ILS/DME frequencies - to set tune mode (AUTO/ MAN) - to do DME HOLD
In AUTO tuning, the NAV source has to be on FMS (Inhibited on V/ILS)
-
MARKER SENSIBILITY SETTING MCDU allows to set MKR sensibility (LO/HI position)
-
ADF CONTROL VOR/ILS ADF MFD ND OVLY
MCP COM 108.90 DME HOLD
OFF / ON RETURN
ACTIVE 357.0 ADF ADF1 K> TONE
ADF2 ACTIVE 351.0 TONE ESC
ATA 34 117.%% PRESET > MKR SENS LO / HI < TUNE MODE AUTO / MAN< 657.0 STBY 1050.0 MCDU
ATA 34 VCP
ACTIVE 340.0 MODE
ADF / ANT OFF / ON < RETURN ADF 1 MCDU
STBY 340.0< PRESET >
MCP and MCDU allow: - to tune ADF frequencies - to set mode (ADF/ANT) - to set tone (OFF/ON)
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Page 169 — 4. TAWS ALERT MODES (Modes 1-2)¶
P. NAVIGATION SYSTEM
- TAWS ALERT MODES ATA 34
The Terrain Awareness Warning System provides visual and aural alerts in case of dangerous flight path conditions which would result inadvertent ground contact if maintained.
The TAWS performs the following alert modes: - Reactive warning modes * Mode 1: excessive descent rate * Mode 2: excessive terrain closure rate * Mode 3: altitude loss after take-off * Mode 4: unsafe terrain clearance * Mode 5: below glideslope * Mode 6: altitude callouts - Predictive warning modes: * Terrain Caution and Warning * Obstacle Caution and Warning
Radio Altitude (ft) MODE 1 excessive descent rate MODE 1 Envelope 2450 - "Sink Rate" 2075 192 1180 - 1000 "Pull Up" 370 - 50 - Vertical Speed (f/min)
MODE 2 excessive terrain closure rate MODE 2 Envelope
310 kts 2450 - < 220 kts 1800 - 006E 1500 AR 790 - "Terrain Terrain" flaps not / "Pull Up" extended flaps in landing configuration 220 - 50 - Terrain Closure Rate (f/mn)
PULL UP GPWS "SINK RATE, SINK RATE" PULL UP GPWS "PULL UP, PULL UP" PULL UP GPWS "TERRAIN, TERRAIN" PULL UP GPWS "PULL UP, PULL UP"
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Page 170 — TAWS Modes 3, 4, 5¶
SYSTEMS 42/72 - 600
MODE 3 altitude loss after take-off Radio Altitude (ft) MODE 3 Envelope PULL UP GPWS "DON'T SINK, DON'T SINK" Radio Altitude (ft) 1500 - "Don't Sink" Altitude Loss (ft)
MODE 4 unsafe terrain clearance MODE 4 Envelope 1000 - PULL UP GPWS MODE 4 Envelope 1000 - "TOO LOW GEAR" 500 - "Too Low Terrain" Radio Altitude (ft) 500 "Too Low Terrain" / "Too Low Gear" / "Too Low Flaps" 245 Computed Air Speed (kts)
MODE 4 Envelope PULL UP GPWS "TOO LOW TERRAIN" MODE 4 Envelope PULL UP GPWS "TOO LOW TERRAIN" 1000 - 1000 - "Too Low Terrain" 500 - "Too Low Gear" / "Too Low Flaps" 245 Radio Altitude (ft) 500 - "Too Low Terrain" / "Too Low Gear" / "Too Low Flaps" 245 Computed Air Speed (kts) Computed Air Speed (kts)
MODE 5 below glideslope MODE 5 Envelope 1000 - PULL UP GPWS "GLIDE SLOPE, GLIDE SLOPE" Radio Altitude (ft) "Glideslope" (6 dB reduced volume) Mode 5A 300 - 150 - "GLIDE SLOPE" Mode 5B Volume increases 30 - Glideslope Deviation (dots)
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Page 171 — Mode 6 (altitude callouts), TCF¶
P. NAVIGATION SYSTEM
MODE 6 altitude callouts MODE 6 Envelope 2450 - 500 Ft DH "Minimums" PULL UP GPWS "BANK ANGLE, BANK ANGLE" "Bank Angle" 30-
TERRAIN CLEARANCE FLOOR (TCF) The Terrain Clearance Floor (TCF) mode creates an increasing terrain clearance envelope around the airport runway directly related to the distance from the runway.
"TOO LOW TERRAIN" 150- Bank Angle (degrees)
700 FT AGL 400 FT AGL 245 FT AGL 4 NM / 1.45 NM RUNWAY
PULL UP GPWS "TOO LOW TERRAIN" PULL UP GPWS "TOO LOW TERRAIN" 15 NM / 12 NM
PULL UP GPWS Runway Field Clearance Floor (RFCF) RFC CEILING (300 FT ABOVE FIELD) FIELD ELEVATION PULL UP GPWS "TOO LOW TERRAIN" RFCF ALERT AREA (NO LOWER LIMIT)
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Page 172 — Terrain and Obstacle Awareness¶
SYSTEMS 42/72 - 600
TERRAIN AND OBSTACLE AWARENESS
This function uses the aircraft geographic position from the GPS, aircraft altitude and a worldwide terrain database to predict potential conflict between the aircraft flight path and the terrain, and to provide aural alert and graphic displays of Terrain Advisory Line Display.
PULL UP GPWS
The terrain advisory line is drawn along the points where a terrain caution alert will occur if the aircraft continues along its current trajectory.
Terrain Caution PULL UP GPWS "TERRAIN AHEAD" Or "OBSTACLE AHEAD"
When a terrain caution or warning occurs, the terrain advisory line is removed from the display and the terrain display is changed to identify the terrain that caused the alert.
Pull-Up Warning PULL UP GPWS "TERRAIN AHEAD, PULL UP" Or "OBSTACLE AHEAD, PULL UP"
The Pull-Up Warning is generated as long as the current aircraft trajectory will not safely clear the terrain, and the aircraft performances are able to clear the terrain in climb.
170
Page 173 — Avoid Terrain Warning, TAWS PB, TAWS PANEL¶
P. NAVIGATION SYSTEM
Avoid Terrain Warning
PULL UP GPWS "AVOID TERRAIN"
The Pull-Up maneuver will not allow for a safe clearance with terrain, and the crew has to immediately initiate an appropriate vertical and turning escape maneuver in order to avoid terrain.
- TAWS PB
TAWS GPWS NORM FLAP OVRD OFF PULL UP
ATA 34
- TAWS PANEL
TAWS selector is guarded in the norm position. FLAP OVRD mode 4 alert caused by flap extension is inhibited to avoid nuisance in case of reduced flaps landing.
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Page 174 — 7. ND OVERLAY¶
SYSTEMS 42/72 - 600
- ND OVERLAY ATA 31
The MCP allows to set ND OVLY: - Traffic - Weather radar - Terrain - Navaid - Airport
172
Page 175 — 8. FMS¶
P. NAVIGATION SYSTEM
- FMS ATA 34
[System architecture diagram — dual FMS installation]
The dual THALES Flight Management System (FMS) installed on ATR 72/42-600 aircraft is composed of two identical sets of software applications, called FMS1 and FMS2. Each FMS is hosted within the DU2 and DU4, normally used with the MFD format. This dual FMS is built on dual cockpit system architecture. It is used to be normally handled with both FMS, synchronized by the cross talk function.
Display Units: - DU 1: PFD (Captain) - DU 2: MFD (Captain) — hosts FMA 1 - DU 3: EWD (shared) - DU 4: MFD (F/O) — hosts FMA 2 - DU 5: PFD (F/O)
Connected via AFDX data bus.
Sensor inputs per side: - GPS 1/2 - NAV 1/2 - ADF 1/2 - DME 1/2 - GPS (dedicated) - HF 1/2 - ATC 1/2 - EEC 1/2 - ADC 1/2
Each side connects to: - Switching panel - Clock 1/2 - MCDU - MCP - FGCP (shared)
CAC 1 and CAC 2 (Core Avionic Cabinets) house the processing modules.
AWRS 1/2 provide weather radar data. AHRS (Attitude and Heading Reference System) data feeds into the system.
Power is supplied via: - Power Pitch trim box - Power Yaw box - Power supply units
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Page 176 — FMS MCDU Interface (continued)¶
SYSTEMS 42/72 - 600
[MCDU and MCP panel layout]
MFD displays (DU2 and DU4): - FMA 1 / FMA 2 (Flight Mode Annunciator) - MFD format with navigation display
MCDU layout: - TOP ANNUNCIATORS - SPARE ANNUNCIATORS - DISPLAY SCREEN - ALERT MESSAGE - HEADING NAVIGATION - LEFT LINE SELECT KEYS (LSK L1–L6) - RIGHT LINE SELECT KEYS (LSK R1–R6) - FMS MENU / QUICK ACCESS - SLEW KEYS - REQUEST - MULTI SYSTEMS SELECTION - ALPHANUMERIC KEYBOARD - SPARE KEY (for COMS or SATCOM) - BRIGHTNESS / CONTRAST CONTROL KEYS - CLEAR KEY
MCP (Multipurpose Control Panel): - POSITION TUNING MODE - NAVIGATION TUNING MODE - EXECUTE - RIGHT LINE SELECT KEYS
Lower MFD views show: - Navigation Display (map mode) - Weather Radar overlay capability
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