NAV/COMMS Flashcards
NAVAIDS, COMMS, SATCOM
Describe three ways to zeroise the AN/ARC-210 VHF/UHF?
1) master zeroise switch on misc. switch panel on centre pedestal (power must be supplied to RT).
2) use discreet selection on the zeroise page of the mcdu.
3) guarded v/uhf zeroise switch at nav station
What frequency band are havequick and sincgars on?
Havequick-UHF
Sincgars-VHF
What is the VHF data radio (VDR) channel spacing?
25kHz
8.33kHz
What are the requirements to transmit data on VDR?
Rotate large ring of tune knob until ‘data’ displays on the VDR LCD display screen, push transfer button to move to upper row (active). Data transmit will not work if ‘data’ shown on both screens.
How many EXCAPS are there and where are they?
8 EXCAPs
- pilot side shelf
- copilot side shelf
- flight instructor, LH distribution panel
- flight engineer, overhead panel
- navigator station, RHS
- navigator console, bunk
- load master 1, FWD LH cargo compartment
- loadmasters 2, AFT LH cargo compartment
What is the ICU used for? (Explain)
- interprets and formats inputs from the excaps
- provides redundant processing of excaps or monitored systems
- forwards these commands to functions responsible for implementing them
- aural/audio advisory and warning tones available at each EXCAP
What happens if all ICSs fail?
Operators will be connected to the designated backup radios (backup mode operation) pilot-v/uhf1 VOR 1 copilot- hf2 VOR 2.
What navaids do the multi-mode receivers work with?
VOR, ILS and Marker Beacon receiver functionality
The TACAN 2 shares 2 antennas with the…?
V/UHF system with high pass filters to prevent interference
TACANs can get certain information in _____ tuning mode, what is it?
Paired tuning mode.
When paired mode selected using onside VOR, distance can be provided by the onside VOR/DME station.
Where would you find notifications of a TACAN failure and what is displayed?
CBIT/IBIT/PBIT-(With failure) Tacan activates RT fault flag,
system BIT fault message in system status page, equipment history page, IBIT results page and scratchpad of the MCDU
What are the various operating modes of the Tacan?
Transmit/receive (A-G) TX/RX- relative bearing from received surface beacon fundamental bearing.
Receive (A-G) RX- both bearing and distance, calculates slant range distance, range rate and time to station.
Receive (A-A) A/A RX- receives and computes bearing info from airborne beacons, transmitter inhibited.
Transmit/receive (A-A) A/A TX/RX-As above but with TX generating signals similar to surface beacon however single pulse. Cooperating a/c can get distance and bearing if equipped with bearing producing equipment.
Where is the information for the ADF displayed?
Data from ADF is displayed on PFD (pointers selected title) and or ND (frequency and idents bottom left or right) with pointer selection on DCP (available in TACAN, VOR or approach mode).
Also on NAV RADIO pg of MCDU.
How long is the initialisation process for the HF RT system (BIT)?
3 mins
When you receive the MSG “active link” what do you do?
press “abort send”
What should the operator ensure before performing a BIT (HF)?
Personnel are not working on external skin
Aircraft is 200ft from: aviation fuel storage areas, aircraft with open fuel lines/systems, ground refuelling of aircraft.
Due to high RF voltage build up.
What are the maximum theoretical drift rates?
- 8nm/hr for pure INS solutions
0. 3nm/hr for blended GPS/INU solutions
What are the various EHE-FOMs
1-<=25m
2-25m
Does the EGI (GPS) Positioning Service use PPS mode or SPS mode?
Default is SPS (standard positioning service) intended for civilian use and endorsed by FAA for use in civil airspace PPS (precise positioning service) is able to be used when keyed with valid crypto keys however we are not certified to use.
What are the four steps to perform stored heading EGI alignment?
1) gyro-compass alignment must be performed prior to powering down the aircraft and INU must reach NAV READY prior to power down.
2) must select ‘inhibit’
3) these stored values are used at next power up (alignment under one minute)
4) must select stored heading mode as alignment mode in INU control page
What are the 7 EGI modes
T/S/O/G/S/I/N
Test Standby Orient Gyro Compass alignment Stored heading alignment In flight alignment Navigation and degraded navigation
What does an EGI in flight alignment require?
GPS FOM 4 or less.
Aircraft in S&L and un-accelerated
up to 10 minutes.
What should be done prior to using position to align INUs?
Check position is accurate prior to down selection or entering.
When can you perform an IBIT for the EGIs?
EGI can be commanded into test mode (IBIT) but only from standby or orient modes.
different types of RAIM display?
- GPS predictive RAIM (pg)-
- Automatic RAIM prediction-
- Waypoint RAIM
- Flight plan RAIM(pg)
What are the 5 types of Nav mode solutions?
Blended INU/GPS INU-Only GPS-Only INU/Radio: RHO-RHO (TACANs) RHO-THETA (a paired TACAN w VOR) No
When and how do you update the INU position?
When INU distance display is significantly different to INU/GPS or GPS position, however not when INU is being used for navigation solution.
1) INU control page LSK L5 for Update page
2) update from either overfly of Navaid, associated GPS or operator entered position
3) use freeze function to note position difference value of INU/GPS position above LSK R5
4) if correct press accept, if wrong press clear and try w different source.
When do you get RNP messages and why?
RNP Unable- ANP=> 2 x RNP An SP fails An EGI fails RNP exceed- TSE exceeds value for RNP
What should be ensured with regards to the ALE and why? (Automatic link establishment)
with- HF antenna RF output terminal on the antenna coupler Antenna lead in wire Insulated feed through
Because serious RF burns can result for contact when system transmitting (which is done automatically in response to ALE calls without operator intervention).
MILSATCOM safety distance?
20ft
What ACARS message will you recieve if your IFF is switched to off?
“ICAO address unavailable”
What are the satellite requirements for RAIM (C-130 LEP specific)?
Can track up to 12 Satellites at any time, needs minimum of 5 for RAIM prediction but only 4 if using baro aiding as barometric info is not required from a 5th satellite.
What are the default RNP values?
Enroute-RNP
Terminal-RNP
Approach-RNP
Enroute-RNP 4
Terminal-RNP 1
Approach-RNP 0.3
Blended integrity protection
EGIs are capable of performing RAIM (receiver autonomous integrity monitoring)
Aircraft to aircraft chat frequencies;
- NZ
- Asia/pacific
- NZ: 128.95
- Asia/pacific: 123.45
Nav Alt changes role
Call;
- 1TG
- “approaching (200 ft TG)
IF NOT CAPTURED BY PILOT
Navaids settings
- Should be MANUAL/PAIRED except when the VOR/DMEs aren’t co-located, then PAIRING should be OFF
- Navaids to be Idented before use for approach
- NOTAMed U/S Navaids to be inhibited
What are the nav radio & sensor subsystems
- GPS/EGI x2
- 2x DADC (Digital air data computers)’
- 2x TACANs
- RADALT
- VHF/UHF DF reciever
- 2x ADF recievers
- Associated control panels
- 2x SPs
What does an AMBER ATTn on the PFD mean
Both PFDs are on the same source (no redundancy)
What does an WHITE ATTn/m on the PFD mean
Both PFDs are off-side, abnormal but still have redundancy
What is the MMR & what is it’s function
Multi-mode reciever
provides VOR, ILS & MB receiver functionality
What is the DADC & what does it provide & where does it provide these to?
Digital air data computers x2 & TAT probe
- Airspeed
- Mach
- Vertical speed
- Alt
- TAT & SAT
AFCPs, SPs, EGPWS, IFF
What does an AMBER ADCn on the PFD mean
Both PFDs are on the same DADC source (no independence)
What does an WHITE ADCn/m on the PFD mean
Both PFDs are offside but redundancy is maintained
What are the 4 TACAN modes
- TX/RX Air-Ground
- RX only Air-Ground
- TX/RX air-air
- Rx only air-air
What is the RADALT function
Provides accurate height measurements above terrain between 0-8000ft AGL
What is the function of the V/UDF Direction finder
What are the SAR freqs
Directs signals from VHF & UHF freq bands & gives relative bearings to the signal.
- 121.5
- 243
- 406
VOR One liner
- Uses Space waves (LOS) and gives a radial/bearing worked out by PHASE COMPARISON between an omnidirectional reference burst and a variable rotating beam which pinpoints the a/c.
- The two beams are in phase at north and get 90 deg out of phase at E/S/W.
ADF/NDB One liner
NDB ground system (omnidirectional ground wave beam) is used by the ADF a/c system so that the a/c can establish its bearing relative to that station.
ILS One liner
Provides instrument and precision approaches by giving vertical and lateral guidance down to 0ft. Used in bad weather and busy airports
TACAN One liner
Is a single display of bearing and distance from a ground or airborne station through the use of space waves and DME.
- 1 x reference antenna (omnidirectional burst)
- 1 x reflector (primary burst)
- 9 x directors (secondary bursts)
One liner for Multi-channel SATCOM (MCS 4000)
mobile comms & avionics system that provides continuous worldwide voice & data comms through INMARSAT satellite system
What 4 categories of comms does thr SATCOM system accomodate
- ATC
- Aeronautical operation control
- Aeronautical administrative comms
- Aeronautical passenger comms
What 3 subsystems make up SATCOM
- A/C earth station (avionics & antenna)
- Space segment (satellite)
- Ground earth station
What four regions does INMARSAT cover?
- Pacific
- Atlantic East
- Atlantic West
- Indian ocean
Where can you terminate a SATCOM call?
The SATCOM/CMU panel at the NAV station or via the MCDU pages
Basic outline of how SATCOM works (a/c - ground)
Accepts data & voice signals, encodes the Modulates the info onto RF carrier freq. transmits to a ground station via a satellite
WARNING associated with SATCOM
Do not operate with pers within 8.5ft of antenna
When doing tests, pers should be a min of 20ft
what is SATCOM listed as on the EXCAP
CSAT
Communication management unti (CMU) one liner
Supports datalink services (interfaces with SPs, MCDU, HF, SATCOM, VHF radios via the AIRNC data bus)
How do you know when you have a datalink
message
Where would you access?
BLUE “DL MSG” on button & audio “datalink, datalink”
ACARS page
in the datalink manager page, what frequencies can you switch VHF readio between
8.33 Khz & 25KHz
What is the frequency range for VHF/UHF
30-399.975 MHz
What is something to note WRT the V/UHF antennas
They are shared with the #2 TACAN system
Where is the MILSATCOM zeroise switch located
what are the 2 other options?
Misc switch panel forward pedestal
- MCDU
- guarded V/UHF zeroise switch at Nav station
V/UHF freqs increments
8.33 KHz
VHF Data radio one-line
2 x functions?
An airborne VHF digital communications transciever that performs two functions;
- Standard AM voice transciever
- Data transciever (CPDLC)
What 3 main functions does the HF system provide
- HF datalink
- Automatic link establishment
- SELCAL
How long does the RT take to power up
3mins to PU & initialise
What is a general rule wrt HF frequencies
- Sun in the sky, frequency high.
What is a catch with regards to recieving a SELCAL & then wanting to change frequencies
ABORT send must be selected in the HF control page
What V/UHF antennas do we have, what are they shared by?
Two antenna, one each for the V/UHF #1 and #2 systems, shared by the #2 TACAN system
WARNING associated with SATCOM antenna
All personnel should be a minimum of 20ft from the SATCOM antenna when performing radio checks. Serious RF burns can result from contact with the antenna whilst transmitting.
- What VDR selections can be made
- What frq needs to be set to enable CPDLC?
- What is the caveat?
Data & Voice
A “data” frq
Both VDRs can’t be selected to data at the same tim
When HF system is turned on, how long is needed until it can be used?
When the RT is powered on through the FMS and requires a three minute initialisation process before it can be used
WARNING associated with the HF BIT (2 parts & 3 condxns)
- Do not transmit or perform BIT when a/c is on the ground and personnel are working on external skin SFC. (High voltage can build up)
- Ground transmit operation of the HF radio system, including BIT is prohibited unless the a/c is 200ft or more from the following;
- Aviation fuel storage areas
- A/c with open fuel lines/system
- ground refuelling of a/c
What are the steps required to perform a stored HDG alignment (4)
- “Fast inertial alignment mode” selected on MCDU
- INU must reach NAV READY before power down & INHIBIT must be selected
- Do not move the aircraft
- Must select SH in mode select of INU control page
to use the FLIGHT PLAN RAIM PAGE, what criteria must be met to achieve predictive RAIM? (5)
- GPS receiver is operational
- Route is active
- Performance has been initialised
- a/c is not airbourne
- Predictive RAIM is not being computed
What are the different navaids that can be selected by the MMR?
- VOR (1 & 2)
- ILS (1 & 2)
- Marker beacon
What are the 4 available TACAN modes of operation?
- Transmit & receive Air-Ground
- Receive only Air-Ground
- Receive only Air-Air
- Transmit & receive Air-Air
EXCAPS backup function - how does it work & what does it give you?
Operators are connected to the designed backup radios;
- Pilot: V/UHF1 & VOR1
- Copilot: HF2 & VOR2
If IFF is switched off, what may not be available?
ACARS ICAO addresses
TACAN antennas - location
TACAN #1: upper & lower fuselage
TACAN #2: Shared with both V/UHF antenna
How do the EGIs maintain their integrity?
What will they do if outside of tolerances?
- GPS receivers in the EGIs are capable of performing RAIM checks to assess a/c ability to operate under RNP constraints
- The FMF will alert the crew
What should you check before updating INU position in flight?
Ensure the INU being updated isnt part of the solution being used for navigation
