adf (draft)
TRANSCRIPT
CHAPTER 34 – NAVIGATION
SECTION 34-53 - AUTOMATIC DIRECTION FINDER (ADF) SYSTEM DESCRIPTION The Automatic Direction Finder (ADF) system supplies the relative bearing data from a ground station for in-flight navigation, terminal navigation, and area guidance. This data gives the aircraft direction to a ground station with relation to the heading. The ADF receiver module, installed in the MRC2, receives RF signal from the ADF antenna, compute the relevant information and sends its data to the NIM. The NIM sends this NAV data on the ASCB-D bus to the NICs in the MAUs and to the EDS. The ADF data, received by NICs, is provided to the FMS processor modules through the MAU backplanes. The FMS uses NAV data from the ADF system to do its NAV functions. The electronic display system (EDS) shows ADF data that gives the radio bearing relative to the aircraft heading. The MRC2, also, transmits the ADF audio signals through the digital audio bus to each audio panel in the audio system. The ADF system uses two bandwidths: − A narrow band mode to reduce noise during navigation − A wideband mode to improve the quality of voice signals. The ADF system is composed by the components that follow: − DF-855 Automatic Direction Finder (ADF) Module − AT-860 Automatic Direction Finder (ADF) Antenna DF-855 ADF Module The ADF module is installed in the MRC2, is powered by +28 V dc, and supplies +15 V dc to the amplifier in the ADF antenna. The ADF module supplies steering data to low-frequency transmitters (beacons) with set frequencies from 190 to 400 kHz, and 1600 to 1799 kHz. It also supplies steering data to the following stations: − Broadcast Stations that Operate with Amplitude Modulation (AM) − Marine Stations that Operate in the Frequency Range of 100 to 190 kHz − Stations on the High Frequency (HF) Distress Frequency of 2182 kHz. The ADF module provides the relative bearing data to the NIM of the MRC2 through the internal bus, but it is also able to supply data to external users on the following way: − as ARINC-407 synchro data, − as direct current (dc) sine/cosine data, and − as RS-422 data. The ADF module has a mute (cancel) function that cancels the radio interference caused by HF signals transmitted from the aircraft. (This interference can cause some avionics to show incorrect ADF bearing indications).
AT-860 ADF Antenna The ADF antenna system contains an internal sense antenna, sine/cosine loop antennas, an amplifier, and a self-test function. The sense antenna is a vertically-polarized antenna that receives the AM audio signals. The sine/cosine loop antennas are horizontally-polarized, perpendicular antennas that receive the relative bearing signals. The amplifier increases the input signals from the internal antennas. The self-test function does a test of the ADF system components. The ADF antenna has a coaxial connector that connects to the ADF module. The antenna is installed on the bottom center outer fuselage. OPERATION The ADF system operates in the frequency range of 190.0 to 1799.5 kHz in increments of 500 Hz (for usual operation). It also tunes frequencies between 100 and 190 kHz, and monitors the maritime emergency frequencies between 2181 and 2183 kHz. In case of an airborne HF radio starts to transmit, the ADF module holds the ADF bearing pointer. If the HF radio transmits continuously for more than 5 seconds, the electronic ADF bearing pointer, shown on the PFD, goes out of view. These condition continues until the HF radio stops in order to prevent possible errors caused by bearing indications that are not accurate. The following table shows the four modes of operation for the ADF system.
MODE DESCRIPTION ANT (antenna) The system receives the ADF signals but does not
calculate the relative bearing. Audio sensitivity and range are set to maximum.
ADF The system receives the ADF signals and calculates the relative bearing. There is some decrease of received audio range and sensitivity.
BFO (beat frequency oscillator) The system receives the continuous wave (CW) signals. The system uses a beat frequency oscillator (BFO) to sense these signals.
VOICE The system increases the intermediate frequency (IF) bandwidth of the ADF module to make the quality of the ADF audio signals better. This mode does not supply bearing.
The VOICE mode supplies high quality audio signals for the headsets and flight compartment speakers. The high quality audio is a result of the wider bandwidth available in the VOICE mode. To find the direction to the ADF station, narrow band reception is necessary to increase the bearing accuracy. Because of the wider bandwidth, it is possible to hear BFO interference when the system monitors different ADF stations that are less than 3 kHz apart. To prevent this interference, use the ANT mode. CONTROLS AND INDICATORS The bearing data from the helicopter, provided by the Automatic Direction Finder (ADF2) over the ASCB-D, is shown on the PFD. This data is shown on the PFD by the diamond pointer when selected by the Diamond Bearing 2 Button of the Display Controller.
ADF Tuning Function The ADF tuning function is done with the MCDU through the ASCB-D, in case of ASCB-D failure a backup MCDU tuning mode lets the pilot or copilot tune the on-side COM and NAV through a direct ARINC 429 link from the MCDU to the radios. Because of this, and having the only ADF2 system installed onboard, during tuning backup mode the ADF system in not available. ADF System Operation with the Multifunction Control Display Unit (MCDU) The MCDU is the primary control unit for the PRIMUS EPIC® radio system. The MCDU controls the operative mode and frequency tune for the ADF2 system through the pages as follows:
1. RADIO 2/2: RADIO 2/2 page displays the radio data for the systems ADF2, COM radios, NAV radios and NAV/COM radios.
2. ADF 2: The ADF2 page displays the active, preset, and selected memory frequencies for the automatic direction finder, the controls for the active mode (antenna or ADF) and the beat frequency oscillators (BFO) setting (ON or OFF). It is also used to access the ADF memory pages.
3. ADF MEMORY: The ADF MEMORY 1/2 and ADF MEMORY 2/2 pages are utilized to store up to 12 ADF memories channels each one having an own associated frequency. In addition to entering or dialing–in frequencies for each memory location, a text label of up to 8 characters can be entered for each stored frequency. The default label for each memory is MEMORY, a dash, and the memory number, with the memory number always on the outboard edge of the display.
CAPTIONS No-one cautions message is available for the CAS window in the event of ADF system failure. Acknowledgement of a not availability of the ADF bearing data or ADF system failure occurs as follows: − ADF bearing pointer frozen: If the onboard HF radio starts to transmit. − ADF bearing pointer out of view: in case of ADF failure or if the onboard HF radio transmits
continuously for more than 5 seconds. LEADING PARTICULARS DF-855 Automatic Direction Finder (ADF) Module − Power Requirements: 28.0 V dc nominal, 30.3 V dc maximum, 22 V dc minimum − Circuit Breaker: 28 V dc 3.0 amps − Types of Reception: CW, AM − Frequency Range: 100.0 to 1799.5 kHz in 0.5 kHz steps − Intermediate Frequencies (IF):
• First IF: 10.7 MHz • Second IF: 4.3 MHz
− Bandwidth: • ANT, ADF, and BFO Modes: ≤ 2.8 kHz at six dB, ≤ 10 kHz at 80 dB • Voice Mode: ≥ 8.0 kHz at three dB, ≤ 26 kHz at 40 dB
− Sensitivity : • ANT Mode : Better than 50 mV/meter for six dB S + N/N for 400 Hz, 30%modulation
• ADF Mode : Better than 100 mV/meter for six dB signal to noise ratio for 400 Hz, 30% modulation
• BFO Mode : Better than 70 mV/meter for six dB signal to noise ratio for 400 Hz, 30% modulation
− Spurious Response: At least 80 dB below the desired response at all frequencies − Audio Output: 100 mW into a 600 load with < 10% distortion − Audio Frequency Response:
• ANT, ADF, and BFO modes: Not more than ±3 dB from 350 to 1100 Hz • Voice Mode: Not more than ±4 dB from 350 to 3200 Hz
34-53-03-010
A
A
A
MODULAR RADIOCABINET #2 (MRC2)
ADF 2MODULE
34-53-03-002
Honeywell Honeywell Honeywell
Honeywell Honeywell
Hon
eyw
ell
ADFANT
DMEANT
TOPANT
MKR
GS
VIL
BOTANT
VHFCOMANT
MRC
CAPTIVE SCREWSADF MODULE HANDLE
WRIST STRAP SOCKET
ELECTRICAL CONNECTOR
ADF MODULE
BACKSHELL ATTACHMENT SCREW
ADF ANTENNA CONNECTOR
34-53-03-009
ADF ANTENNA
34-53-03-001
ADF ANTENNA
SCREW
GASKET
ADF ANTENNA CONNECTOR
34-53-03-008
MCDUCPLT
MCDUPLT
PFDCPLT
PFDPLT
MAU1
MAU2
ADFAIR
MODULE
ADFMODULE
ADFANTENNA
ADF AUDIO OUT +15 Vdc PWR
LOOP AMP. ENABLE
ADF SIN/COS MODULAT.
ANT. TEST ENABLE
RF
28 Vdc PWR
RCB
+28VdcMAIN 2
NAV/COMADF
NIM NIM
CPLT AUDIOPANEL
PLT AUDIOPANEL
429 429
DIGITAL AUDIO BUSES
ASCB-D
DIGITAL MIC BUSES
MRC 1 MRC 2
34-53-03-003
N33
30W
24
21S
15
12E
6
3
160
140
150
100
110
130
80
90
2000
18 2040
34-53-03-003
N33
30W
24
21S
15
12E
6
3
160
140
150
100
110
130
80
90
2000
18 2040500
VOR GS 22.00150 ROL PIT 750
20
20
10
10
20
20
10
10
AHRS1 ADS2
1210
IGS110 12.50 IN
2
1
1
2
VTA
63 63 100PI
FUEL KG
FF KPH
NRNF NF
TQ TQ
APP
KDVT
DR
1.7 NM
MSG
1+22ETE
VOR1
ADF2
600
500
400
250
200
150
300
118.03 109.05 3180 118.03COM1 NAV1 XPDR COM2
MAN
MAN
FAIL
IDLE
1200
600 600
100 100
1CASMSCP
15
N33
30W
24
21S
15
12E
6
3
63 63 100PI
FUEL KG
FF KPH
NRNF NF
TQ TQ
APP
KDVT
DR
1.7 NM
MSG
1+22ETE
VOR1
ADF2
600
500
400
250
200
150
300
118.03 109.05 3180 118.03COM1 NAV1 XPDR COM2
MAN
MAN
FAIL
IDLE
1200
600 600
100 100
1CASMSCP
15
VOR2/ADF2 BEARING POINTER SOURCE INDICATION
ADF2 BEARING POINTER
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N33
30W
24
21S
15
12E
6
3
160
140
150
100
110
130
80
90
2000
18 2040500
VOR GS 22.00150 ROL PIT 750
20
20
10
10
20
20
10
10
AHRS1 ADS2
1210
IGS110 12.50 IN
2
1
1
2
VTA
63 63 100PI
FUEL KG
FF KPH
NRNF NF
TQ TQ
APP
KDVT
DR
1.7 NM
MSG
1+22ETE
VOR1
ADF2
600
500
400
250
200
150
300
118.03 109.05 3180 118.03COM1 NAV1 XPDR COM2
MAN
MAN
FAIL
IDLE
1200
600 600
100 100
1CASMSCP
15
N33
30W
24
21S
15
12E
6
3
63 63 100PI
FUEL KG
FF KPH
NRNF NF
TQ TQ
APP
KDVT
DR
1.7 NM
MSG
1+22ETE
VOR1
ADF2
600
500
400
250
200
150
300
118.03 109.05 3180 118.03COM1 NAV1 XPDR COM2
MAN
MAN
FAIL
IDLE
1200
600 600
100 100
1CASMSCP
15
VOR2/ADF2 BEARING POINTER SOURCE INDICATION
ADF2 BEARING POINTER
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N33
30W
24
21S
15
12E
6
3
160
140
150
100
110
130
80
90
2000
18 2040500
VOR GS 22.00150 ROL PIT 750
20
20
10
10
20
20
10
10
AHRS1 ADS2
1210
IGS110 12.50 IN
2
1
1
2
VTA
63 63 100PI
FUEL KG
FF KPH
NRNF NF
TQ TQ
APP
KDVT
DR
1.7 NM
MSG
1+22ETE
VOR1
ADF2
600
500
400
250
200
150
300
118.03 109.05 3180 118.03COM1 NAV1 XPDR COM2
MAN
MAN
FAIL
IDLE
1200
600 600
100 100
1CASMSCP
15
N33
30W
24
21S
15
12E
6
3
63 63 100PI
FUEL KG
FF KPH
NRNF NF
TQ TQ
APP
KDVT
DR
1.7 NM
MSG
1+22ETE
VOR1
ADF2
600
500
400
250
200
150
300
118.03 109.05 3180 118.03COM1 NAV1 XPDR COM2
MAN
MAN
FAIL
IDLE
1200
600 600
100 100
1CASMSCP
15
VOR2/ADF2 BEARING POINTER SOURCE INDICATION
ADF2 BEARING POINTER
34-30-03-005
BRG NAV
ALT SEL BARO
HSI
PRV
MAP
LNAV
VX
BRG
DIAMOND BEARING 2POINTER SOURCE SELECTOR
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PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
R A D I O 2 / 2 R A D I O 1 / 2
A D F 2
A D FM E M O R Y 1 / 2
A D FM E M O R Y 2 / 2
34-53-03-004
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
R A D I O 2 / 2 R A D I O 1 / 2
A D F 2
A D FM E M O R Y 1 / 2
A D FM E M O R Y 2 / 2
34-53-03-004
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
R A D I O 2 / 2 R A D I O 1 / 2
A D F 2
A D FM E M O R Y 1 / 2
A D FM E M O R Y 2 / 2
34-53-03-005
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
R A D I OV O I C E A D F 2
6 0 0 . 0
3 2 6 . 0
2 / 2
34-53-03-006
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
A D F 2A C T I V E
P R E S E T
M E M T U N E
A D F
3
2 2 4 . 0
1 2 9 9 . 5
M E M O R Y R A D I O 2 / 2
S D L N D B
6 0 0 . 0
1 / 1
A N T E N N A B F O V O I C E
M O D E
34-53-03-007
PERF
MENU
NAV PREV
NEXT
FPL PROG DIR
RADIO
A D F M E M O R Y
A D F 2
1 - M E M O R Y
2 - M E M O R Y
3 - M E M O R Y
9 6 0 . 0
2 2 4 . 0
1 0 9 2 . 0
R A D I O 1 / 2
1 1 2 3 . 0
1 / 2
A D F 2
M E M O R Y - 4
M E M O R Y - 5
M E M O R Y - 6
NOTE: ADF MEMORY 2 / 2 page is the same as ADF MEMORY 1 / 2 page. The only difference is the locations numbered from 7 to 12.