DEPENDENT POS DETERMINING SYS & LAND AIDS OF AIRBUS
LANDING AIDS
The navigation systems that require external inputs of the aircraft to
operate are: the landing aids systems, the dependent position determining
systems and the Head-Up Display (HUD) system. They include:
- ILS,
- marker system,
- GPS,
- ATC/Traffic Collision Avoidance System (TCAS)/Traffic and Terrain
Collision Avoidance System (T2CAS) as option,
- DME,
- ADF,
- VOR.
LANDING AIDS (continued)
ILS AND MARKER SYSTEM
The ILS sends to the flight crew or Autopilot (AP) signals for optimum
descent path for landing. The ILS signal reception is done in part by
the Multi-Mode Receiver (MMR). The system gives lateral guidance
and vertical guidance to the aircraft approaching the runway.
The marker beacon system is a radio navigation aid that, in conjunction
with an instrument landing system, indicates the distance between the
A/C and the runway threshold. The marker function is done inside
the VOR receivers, but it is only active in VOR 1. There are three
types of marker beacons:
- the outer marker,
- the middle marker,
- the inner marker.
When the aircraft goes over the beacons, the marker beacon
information is displayed flashing on the PFDs, with related audio
signals.
LANDING AIDS (continued)
LANDING AIDS CONTROL AND INDICATING
The ILS information is displayed on the PFDs as 2 scales. One
horizontal scale for the localizer signal and one vertical scale for the
Glide Slope (G/S) signal.
Note that for redundancy:
- ILS 1 is displayed on PFD 1 and ND 2,
- ILS 2 is displayed on PFD 2 and ND 1.
LANDING AIDS (continued)
HEAD-UP DISPLAY (OPTION)
The HUD is an optional flying aid system, which gives to the pilot
an image superimposed on the outside world in his field of view. This
aid is based on the principle of symbol projection on an external
combiner, mainly composed of a flat sheet of glass.
The objectives of the HUD are :
- to supply guidance information on the ground, at take-off and landing
in conditions of reduced visibility;
- to give information to the pilot for visual approach on airfields
without Instrument Landing System (ILS);
- to monitor the automatic approach operations.
LANDING AIDS (continued)
HEAD-UP DISPLAY CONTROL
The HUD system is composed of one HUD set (giving head up data
for the CAPT).
The HUD is composed of:
- one Head-Up Computer (HUDC),
- one Head-Up Projection Unit (HPU),
- one Head-Up Combiner Unit (HCU) and,
- one HUD Control Panel.
The HUDC is installed in the avionics bay 86VU.
It is used:
- to centralize the source data from the aircraft systems,
- to send the necessary data to the HPU.
The HPU is installed inside the cockpit above the Captain.
It is used to project the image towards the HCU. The projected image
is sent to the HCU by the HPU optical lenses.
The HCU is installed inside the cockpit in front of the Captain forward
field of view.
It is used to reflect the image projected by the HPU towards the pilot
while the forward field of view remains visible through the combiner.
One HUD Control Panel on 131VU in the cockpit left hand side is
composed of:
- A HUD potentiometer used to switch ON/OFF the HUD,
- A DECLUTTER pushbutton switch used to change the display,
- And an X WIND switch also used to change the display.
LANDING AIDS (continued)
HCU DISPLAY
According to the flight configuration, different displays can be shown
to the pilot.
Here is an example of HUD image during take off.
RADIO NAVIGATION SYSTEM
The A/C has the following equipment installed:
- two VOR/marker receivers,
- two DMEs interrogators,
- two MMRs: ILS and GPS,
- two ADFs receivers.
NORMAL TUNING
The Flight Management and Guidance Computers (FMGCs) contain
the navigation computer function that calculates the aircraft position.
The FMGCs tune the radio navigation receivers automatically and
use the navigation info from these receivers for display and also in
background for A/C position computation. The Jeppesen database is
loaded in the FMGCs. This information includes: station identifiers,
and specific information (frequency, identification and coordinates)
about the station.
Access to the MCDU RADIO NAV page lets the crew manually tune
the radio navigation receivers, via the FMGCs for display. Manual
tuning overrides automatic tuning.
RADIO NAVIGATION SYSTEM (continued)
BACKUP TUNING
Radio Management Panel (RMP) 1 and 2 are capable of tuning the
own side Navigation receivers in backup mode if both FMGCs have
failed or both MCDUs have failed and manual tuning is needed by
the crew.
RADIO NAVIGATION SYSTEM - BACKUP TUNING
RADIO NAVIGATION SYSTEM (continued)
RADIO NAVIGATION CONTROL and INDICATING
The EFIS control panel mode switches control what type of
information is shown to the flight crew on the ND. They are located
on both sides of the glareshield. The toggle switches on the EFIS
control panel enable the display of the VOR or ILS pointers on the
ND. RMPs are located on the center pedestal.
RADIO NAVIGATION SYSTEM (continued)
ND MODES
There are five different ND modes that can be selected via the EFIS
control panels. These modes are the PLAN, ARC, NAV, VOR, and
ILS modes.
MMR (GPS PART) SYSTEM
The GPS receiver uses data sent by 24 satellites.
MMR (GPS PART) SYSTEM (continued)
NETWORK ARCHITECTURE
GPS data may be processed and used by anyone. The satellite system
transmits precise phase, and time signals. These signals are decoded,
synchronized and triangulated by the receivers.
There are four monitor stations:
- Hawaii,
- Ascension Island,
- Diego Garcia,
- Kwajelein.
The master control station transmits orbital decay information
(Ephemerid data) back to the satellites so that, in the user receiver,
these distance errors can be compensated. The system gives accurate
position, altitude and time information. This information is supplied
to the FMGCs for aircraft present position calculation.
MMR (GPS PART) SYSTEM (continued)
GPS CONTROL AND INDICATING
The GPS data is accessible on the MCDU. Selecting DATA page P/B
on the MCDU and then the GPS monitor line select key, will give the
information related to the GPS receivers.
GPS when receiving adequate signals to calculate a present position
will be annotated at the bottom of the ND. This is displayed as "GPS
PRIMARY".
ATC/TCAS SYSTEM
The Single Aisle family has two ATC transponders, which respond to
the ATC secondary surveillance radar and TCAS (or T2CAS option)
interrogations.
ATC/TCAS SYSTEM (continued)
TCAS PRINCIPLE
The TCAS gives traffic information and warnings of potential conflicts
to the crew, with vertical avoidance instructions. TCAS can only
detect and indicate intruders that have at least one operative ATC
transponder.
The Traffic and Terrain Collision Avoidance System (T2CAS) is a
combination of two functions in a single line replaceable unit (LRU).
The Terrain Awareness and Warning System (TAWS) of the T2CAS
is the part of the T2CAS that ensures the EGPWS functions. The
Traffic Collision avoidance System (TCAS) part of the T2CAS is the
part that ensures the same functions as the TCAS.
ATC/TCAS SYSTEM (continued)
ATC/TCAS SYSTEM
In normal operation Air Data Reference (ADR) 1 supplies barometric
information to ATC 1, ADR 2 supplies ATC 2.
The ATC transponder is an integral part of the ATC radar beacon
system. The transponder is interrogated by the ground station and
replies with a series of pulses. These reply pulses are coded to supply
identification MODE A and altitude reporting MODE C, and selective
call and flight data MODE S on the Air Traffic Controllers (ATCs)
radar scope.
This information enables the controller to distinguish the A/C and to
maintain effective ground surveillance of the air traffic.
ATC/TCAS SYSTEM (continued)
ATC/TCAS CONTROL AND INDICATING
The single control panel on the center pedestal is used for the controls
of the ATC and TCAS (or T2CAS) systems.
ATC/TCAS SYSTEM (continued)
TCAS INDICATING
Here are the different indications that are given by the TCAS (or
T2CAS) computer linked to audio warnings.
COMPONENT LOCATION
Let's see the location of the different navigation systems LRUs.
The radio navigation receiver antennae are installed on the upper and
lower fuselage:
- DME,
- ATC,
- ADF,
- VOR,
- MMR.
- HUDC (optional)
The radio navigation receiver antennae are located on the upper and lower
fuselage:
-TCAS (or T2CAS),
- Enhanced Ground Proximity Warning System (EGPWS).
COMPONENT LOCATION (continued)
NAVIGATION ANTENNAS LOCATION (1/3)
The MMR, ADF and VOR antennae are installed on the upper and
lower portion of the fuselage.
COMPONENT LOCATION (continued)
NAVIGATION ANTENNAS LOCATION (2/3)
The marker antenna and DME antennae are installed on the lower
portion of the fuselage. There are also two TCAS (or T2CAS)
antennae, (1 at the top, 1 at the bottom).
COMPONENT LOCATION (continued)
NAVIGATION ANTENNAE LOCATION (3/3)
The four ATCs antennae are located on the upper and lower portion
of the fuselage.
The G/S and Localizer (LOC) dual antennae are located in the radome.
MAINTENANCE/TEST FACILITIES
All navigation systems can be tested from the MCDUs.
SUMMARY
This picture lists the navigation systems that are installed on the Single
Aisle A/C.
