A320/A319 Flight Management & Navigation
Terms in this set (40)
Give a breakdown of how the Flight Management System (FMS) is operationally splitinto three parts.
The three main parts of the FMS include a:
1. Flight Guidance (FG) portion
2. Flight Management (FM) portion
3. Flight Augmentation portion
Which portion of the Flight Management & Guidance Computers (FMGCs) is directly responsible for providing flight management functions?
Two identical Flight Management & Guidance Computers (FMGCs) are installed in the aircraft. Each FMGC is divided into two components: a Flight Management (FM) component and a
Flight Guidance (FG) component. The FM component is specifically responsible for providing flight management functions.
Provide a basic overview of the functions provided by the flight management portion of the FMS.
Flight management functions include:
2. flight planning
3. performance predictions
4. performance optimization
5. navigation radio auto tuning
6. display management
What are the items that are stored within the FMGCs' navigation database?
The nav database, updated every 28 days, has a wide range of standard navigation data including:
5. holding patterns
7. departure, arrival, and approach procedures
What are the operating modes of the FMGC's?
There are three operating modes of the FMGCs: Dual, Single, & Independent.
Describe the Dual mode of the FMCGs.
Dual: the normal mode of operation; both FMGCs
- data entered into one MCDU also enters into the
corresponding FMGC; this data also transfers to
the opposing FMGC through a cross-talk bus.
- One FMGC is declared the master; the master
FMGC is determined by the following logic:
1. if one autopilot is engaged, the
corresponding FMGC is the master
2. if both autopilots are engaged, FMGC 1 is
3. if neither autopilot is engaged, FMCG 1 is
4. if one FMGC is inoperative, the opposing
FMGC is the master
Describe the Single mode of the FMCGs.
Single: the mode of operation if an FMGC fails.
- the remaining FMGC provides most of the
related features, but with limitations.
- Single Mode operation can be recognized by
the following indications:
a. "1FD1" or "2FD2" presented in column
five of the FMA
b. the messages "MAP NOT AVAIL" and
"SET OFFSIDE RNG/MODE"
presented on the failed side's ND
c. the scratchpad message "OPP FMGC
IN PROCESS" on failed side's MCDU
Describe the Independent mode of the FMCGs.
Independent: caused by a significant mismatch
between the two FMGCs
- no cross-talk occurs between the two FMGCs
- entries made on one MCDU only affects its
associated FMGC; for example, a flight plan
entered on the CA's MCDU would also have to
be entered into the FO's MCDU separately
- Independent Mode operation can be recognized
by the scratchpad message "INDEPENDENT
OPERATION" which appears on both MCDUs.
Explain the difference between an FMGC
failure vs. an FMGC reset.
- During an FMGC failure, the affected FMGC will
completely stop sending data or receiving inputs
and is unavailable for the remainder of the flight.
- During an FMGC reset, an error has occurred in
software processing, and the affected FMGC will
attempt to automatically restore itself.
List the components that provide navigational input to the FMS.
-2 Flt Management & Guidance Computer/FMGCs
- 2 VOR receivers
- 2 DME receivers
- 2 Multi Mode Receivers (MMR),the MMR is a
single unit that incorporates 1 ILS receiver and 1
- Air Data and Inertial Reference System (ADIRS)
- two Radio Altimeters (RAs)
- one marker beacon receiver
List the components used to directly interact and monitor the performance of the FMS.
- the EFIS displays
- the Flight Control Unit (FCU)
- the EFIS control units
- 2 Multi-Function Control & Display Units/ MCDU
- the ADIRS Control and Display Unit (CDU)
- two Radio Management Panels (RMPs)
- Digital Distance and Radio Magnetic Indicator
Describe how the FMS auto tunes certain
navaids for various purposes.
- During takeoff, if the departure runway is served
by an ILS, the FMS auto tunes the ILS frequency
to provide localizer guidance during the t/o roll.
-The FMS auto tunes DME stations en route for
-The FMS auto tunes VOR stations en route to
assist with orientation.
- When an ILS approach has been loaded into the
flight plan, the FMS auto tunes the ILS frequency
to provide final approach guidance during the
Describe how each DME receiver is divided into five channels for position
updating and DME display.
The 5 channels in each DME receiver allow the FMGCs to tune multiple DME's simultaneously.
- 3 channels are used by the FMGCs for position
updating; each FMGC auto tunes multiple DME
stations to determine the aircraft's position
- one channel is used for VOR/DME display
- one channel is used for localizer DME display
Know whether or not the VOR/DME information presented on the NDs is
used for position updating.
Even though the VOR/DME information presented on the NDs is typically auto tuned by the FMGCs, it is not used for position updating. It is solely provided for orientation purposes.
How do you determine if a navaid has been properly tuned and identified?
The presence of a 4 or 3 letter identifier specifically indicates that a station has been identified.
Describe how to manually tune a VOR using the MCDU.
Manually tuning a navaid through the MCDU is accomplished by selecting the RAD NAV (radio navigation) key.
Describe how to manually tune a VOR using an RMP.
Tuning a navaid through the RMP is usually only accomplished if the MCDUs are not available. Tuning through an RMP serves as a backup.
NOTE: this method inhibits all auto tuning
capability of the FMGCs!
-Select the "NAV" key under STBY NAV on the
RMP; a green light will illuminate next to the key.
- Select the "VOR" key under STBY NAV on RMP;
another green light will illuminate next to that key.
- Use the dual rotary knobs to set the desired VOR
freq in the STBY/CRS window of the RMP.
- Select the transfer key to transfer the STBY
frequency into the ACTIVE window.
- Use the dual rotary knobs to set the desired
course in the STBY/CRS window.
- the VOR may now be monitored the same way
as mentioned w/ tuning a VOR through MCDU.
In the lower corners of the NDs, describe how to the difference if a VOR is being auto tuned vs. manually tuned.
The VOR/ADF selector switches must be placed to "VOR" for this demonstration.
- If a station is being auto tuned, it will simply
contain the station's three letter identifier ONLY.
- If a station has been manually tuned through the
MCDU, an underlined "M" appears behind the
station's three letter identifier.
- If a station has been manually tuned through an
RMP, an underlined "R" appears behind the
station's three letter identifier.
a. The CA's RMP controls VOR 1, so this only
applies if the #1 VOR/ADF selector switch is
placed to "VOR". If the #2 VOR/ADF selector
switch is placed to "VOR", and nothing has
been manually tuned in the FO's RMP (which
controls VOR 2), the indication "VOR2"
appears in the lower right corner of the ND.
b. Additionally, once the "NAV" key has been
selected on either RMP, all of the fields of the
RAD NAV page of the MCDU will be blank.
Describe the mode selector switches located on the overhead ADIRS
Control and Display Unit (CDU).
The mode selector switches are used align and depower the ADIRS. A switch is provided for each individual ADIRU; the first controls ADIRU 1, the second controls ADIRU 3, and the third controls ADIRU 2.
OFF: the ADIRU not energized; ADR and IRU data
will not be available.
NAV: this position powers to the ADIRU and
initiates IRU alignment; normal setting.
ATT: used if the ADIRU loses the ability to
navigate, but attitude and heading may be
How long does it take for a full alignment of the IRUs and a quick realignment?
Full alignment takes 5-10 minutes.
Quick realignment takes 3 minutes.
How do you perform a quick realignment of the IRUs?
A quick realignment is performed by placing all three mode selector switches from NAV to OFF, and then back to NAV within five seconds.
What does the memo, "IRS IN ALIGN > 7MN" mean?
An ADIRS countdown clock is presented in the memo section of the E/WD. Since a full alignment takes 5-10 minutes, any time remaining that is greater than 7 minutes is shown as "IRS IN
ALIGN > 7 MN". Once the remaining time reaches less than 7 minutes, the memo will then reflect the corresponding timeremaining for IRU alignment.
Describe the difference in steady white ALIGN lights vs. flashing ALIGN lights within the IR1/3/2 indicators on the overhead ADIRS CDU.
The white ALIGN lights illuminate when the corresponding mode selector switch is placed from OFF to NAV. The light remains
steady if the respective IRU is operating normally in the align mode. The ALIGN lights will flash if there is a fault with the alignment process.
What faults results in flashing ALIGN lights?
- the aircraft was moved during the alignment process
- a present position entry was never made on the MCDU's
INIT page, and more than 9 minutes have elapsed since
IRU alignment was initiated
- the position "memorized" by the IRU(s) differs from the
present position entered in the MCDU by more than 1° oflatitude or 1° of longitude
What does an illuminated ON BAT light indicate on the overhead ADIRS CDU?
The ON BAT light illuminates amber:
- one or more ADIRUs is running on battery (DC)
- as each ADIRU is powered while on the ground
(the mode selector switch is placed from "OFF"
to "NAV" during preflight)
a. the light illuminates for five seconds as each
ADIRU conducts a power up test
b. this only applies to full alignments...not quick
Explain the difference between a steady vs.flashing IR 1/3/2 FAULT light.
The amber FAULT light illuminates steady if the
has experienced a total failure.
- The amber FAULT light flashes if the present
position of that IRU has been lost, but attitude
and heading may be restored through in flight
alignment of the affected IRU.
Explain the difference between aircraft
equipped with hybrid GPS architecture vs.
those equipped with autonomous architecture.
- Hybrid Architecture (all 319s and newer 320s):
the MMRs first process the data they receive
and transmit it to the ADIRS. The ADIRS then
take this information to calculate a combined
GPS/IRS position. Each FMGC then uses and
applies this as the aircraft's "hybrid" position.
a. this position is shown on the POSITION
MONITOR page of the MCDU as "GPIRS"
with the associated lat/long coordinates
- Autonomous Architecture (older 320s): The
FMGCs apply position information supplied by
the ADIRS and the GPS independently. Each
FMGC first filters the IRS provided data and
places priority on the GPS derived position. If
GPS information becomes unavailable, the
FMGC will then apply the mixed IRS position.
a. this position is also shown on the
POSITION MONITOR page of the MCDU as
GPS" with the associated lat/long
List the order of priority in which FMS
positioning is derived using the navigation systems while en route.
4. Mix IRS position
Explain the concept of a "bias".
The FMGCs memorize the difference between the flight management position and the mix IRS position. This difference is called a "bias". The bias is constantly updated when radio
positioning is available. If the radio position is lost in flight, the bias remains constant until a new radio position is achieved.
Define the flight phases of the FMS.
How does the aircraft transtionfrom one phase to the next phase of flight?
PREFLIGHT to TAKEOFF: when takeoff pwr is set
TAKEOFF to CLIMB: when passing the accel alt
CLIMB to CRUISE: cruise altitude is reached
CRUISE to DESCENT: within 200 NM of the dest,
or when less than FL200 has been selected
DESCENT to APPROACH: when passing an FMS
computed approach deceleration point or
APPROACH to GO-AROUND: when the thrust
levers are placed in the TOGA stop and the
flaps are extended
APPROACH to DONE: 30 secs after touchdown
Know the managed speeds calculated by the FMS for each of the flight phases.
The flight phases have an associated optimum speed calculated by the FMS. These are referred to as managed speeds. The managed speeds provided for each flight phase are:
- TAKEOFF: Speed Reference System, or SRS
a. this equals V2 + 10 for both engines running,
or V2 single-engine
a. below 10,000' MSL: 250 KIAS
b. above 10,000' MSL: ECONomy CLIMB
- CRUISE: ECONomy CRUISE SPEED
-above 10,000' MSL: ECONomy DESCENT
a. below 10,000' MSL: 250 KIAS
NOTE: "ECON" speeds are simply calculated
by the FMS based upon factors such as Cost
Index, gross weight, and ambient conditions.
They provided the optimal speed for a given
- APPROACH: maneuvering speed for the current
configuration; these are:
a. "clean" configuration: "Green Dot" (depicted
with a little green circle on the airspeed tape)
b. FLAPS 1: "S" speed (depicted with a
green "S" on the airspeed tape)
c. FLAPS 2 & 3: "F" speed (depicted with a
green "F" on the airspeed tape)
d. FLAPS FULL: VAPP (V Approach) (depicted
as a magenta triangle on the airspeed tape.
These speeds will be maintained provided the aircraft is in MANAGED speed. Selected speeds can always override managed speeds. This is performed by pulling the speed knob on the FCU.
Provide an overview of each of the page keys on the MCDU.
DATA: selects the DATA INDEX page. This provides access to additional pages that display things like position, aircraft status, database items, and pilot stored data.
INIT: displays the INIT (initialization) page. Broken
down into INIT pages A and B, these pages allow for flight plan initialization and entry of basic flight
PERF: accesses the various aircraft performance pages that display data, predictions, and speeds associated witheach FMS phase of flight. When selected, the first page in view reflects information for the current phase of flight.
PROG: displays the prog page. It reflects info that is constantly being updated by the FMS.
DIR: the DIR TO (direct to) page which allows you to go direct to a navaid, nav fix, or a waypoint.
F-PLN: displays the flight plan page where a leg by leg description of the active route can be viewed and modified. When selected, the "top" of the flight plan is shown.
RAD NAV: displays the RADIO NAV page where select navaids that have been autotuned by the FMGCs can be viewed. Also allows you to manually tune navaids.
FUEL PRED: displays the FUEL PRED (fuel prediction page). Fields such as fuel and time predictions are shown. It also shows the FMGC calculated fuel values along with the aircraft gross weight.
SEC F-PLAN: displays the SEC INDEX page which allows access to the secondary flight plan features.
ATC COMM: accesses the ATC MENU pages that
allows for datalink communications with ATC. This
key/page is not active for the A320/A319 fleet.
MCDU MENU: this serves as the main menu key. It
allows access to various systems linked to the MCDU. This includes FMGC, ACARS, and CFDS functions.
AIRPORT: this also displays the flight plan page.
When selected, the "bottom" of the flight plan is shown.
Describe the self-test feature of the radar.
The radar performs a 45 second self-test when turned ON. It also performs a quick self-test at the end of each radar sweep. Any applicable failure messages appear on the NDs.
Note: the radar is fully functional when turned ON even during the 45 second self-test; it does not require a warm up period.
Define each of thefeatures associated withthe MODE selector knob located on the radar panel.
WX: only displays returns associated with precipitation; black indicates a low intensity followed by green, amber, and red to represent progressively higher intensities.
WX+T: displays both precipitation returns and
turbulence; turbulence is shown in magenta on the NDs.
TURB: areas of turbulence are shown only.
MAP: the radar operates in a ground mapping mode; black indicates water, green indicates the ground, and amber is used for man-made structures or high terrain.
Know which ND rangesmust be used for seeing areas of turbulence (magenta).
To display turbulence, the ND range must be set to 40 miles or less (40, 20, or 10).
Why is judicious TILT management required when operating the radar on the A320/A319?
The system incorporates a flat-plate antenna producing a much narrower beam (3°) of energy compared to traditional parabolic antennas. This results in better precision at longer ranges, but requires more TILT and GAIN management, especially at thehigher altitudes.
Describe the features of the GAIN selector knob.
The radar's receiver sensitivity is determined by the setting of the GAIN selector knob.
CAL: provides a predetermined "calibrated"
sensitivity level; below FL250, this setting
provides the best resolution of precipitation.
MIN-MAX: this range allows you to manually adjust
the receiver's sensitivity. MIN yields a
sensitivity always greater than CAL;
increasing the knob up through MAX
increases the sensitivity by 3000%.
a. The word "MAN" appears on the NDs
when these settings are used.
b. It is recommended to use manual GAIN
settings when above FL250.
Know what placing the spring-loaded GND
CLTR SPRS to ON accomplishes.
This feature allows you to eliminate approximately 85% of ground clutter targets that may appear during normal precipitation detection modes. Ground targets will be identified in magenta. The switch is spring-loaded to the OFF position.
List the conditions that would cause the yellow alert bar to appear on the NDs.
A yellow alert bar appears at the top of the ND where radar attenuation has been detected. In order for this feature to display, the GAIN must be set in CAL, and the intervening weather must be within 80 NM of the aircraft.