NAV Navigation

Question 1

The Air Data and Inertial Reference System (ADIRS) supplies ___ to the EFIS system (PFD and ND) and to other user systems (FMGC, FADEC, ELAC, SEC, FAC, FWC, SFCC, ATC, GPWS, CFDIU, CPC).
4 items

Answer 1

temperature, anemometric, barometric and inertial parameters

Question 2

ADIRS system includes:

Answer 2

‐ Three identical ADIRUs (Air Data and Inertial Reference Units).
‐ One ADIRS control panel on the overhead panel for selection of modes (NAV, ATT, OFF) and indications of failures.
‐ Four types of sensors:
‐ Eight ADMs (Air Data Modules) which convert pneumatic data from PITOT and STAT probes into numerical data for the ADIRUs.
‐ A switching facility for selecting ADR3 or IR3 for instrument displays in case of ADIRU1 or 2 failure.

Question 3

Each ADIRU is divided in two parts, either of which can work separately in case of failure in the other:

Answer 3

• The ADR part (Air Data Reference) which supplies barometric altitude, airspeed, Mach, angle of
  attack, temperature and overspeed warnings.
• The IR part (Inertial Reference) which supplies attitude, flight path vector, track, heading,
  accelerations, angular rates, ground speed and aircraft position.

Question 4

The Air Data and Inertial Reference System (ADIRS) includes four types of sensors:

Answer 4

• Pitot probes (3)
• Static pressure probes (STAT) (6)
• Angle of attack sensors (AOA) (3)
• Total air temperature probes (TAT) (2)
  These sensors are electrically heated to prevent from icing up.

Question 5

ADIRU (1) is supplied by CAPT probes,
ADIRU (2) is supplied by F/O probes,
ADIRU (3) is supplied by ___

Answer 5

STBY probes and CAPT TAT.

Question 6

IRS are normally initialized with the FMGC, but IRS may be initialized with the ___ as a backup.

Answer 6

ADIRS CDU

Question 7

MAXIMUM DIFFERENCES BETWEEN SPEED/MACH INDICATIONS
They are provided in order for flight crews to determine if indeed ___ should be requested.

Answer 7

maintenance actions

Question 8

Mach values lower than ___ in climb, and ___ in descent, are not displayed on ISIS.

Answer 8

M 0.50 / M 0.45

Question 9

ADIRS - ABNORMAL OPERATIONS
Backup Speed/Altitude Scale
The BackUp Speed Scale (BUSS) enables to fly the aircraft when

Answer 9

airspeed indications are unreliable.

Question 10

When the BackUp Speed Scale (BUSS) is activated:

Answer 10

‐ The BUSS replaces the normal speed
‐ The GPS altitude replaces the barometric altitude scale.

Question 11

The reversible BUSS is activated and deactivated with two BKUP SPD/ALT pb available on the main instrument panel:

Answer 11

‐ One on the left of the Captain PFD
‐ One on the right of the F/O PFD.

Each BKUP SPD/ALT pb independently commands the display of the BUSS on its associated side.

Question 12

The BUSS information is based on

Answer 12

the angle of attack (AOA), and depends on the slat/flap configuration.

Question 13

ECAM ALERT AND MEMO
The ECAM displays a memo when the flight crew activates the BKUP SPD/ALT on one side:

Answer 13

BKUP SPD/ALT.

Question 14

The non-reversible BUSS is displayed on both PFDs when

Answer 14

the flight crew turn off all ADRs.

Question 15

BACKUP ALTITUDE SCALE
The ___ is no longer displayed.

Answer 15

vertical speed indication

Question 16

SPEED MONITORING FUNCTION
The Speed Monitoring Function is provided by ___. This function uses four different speed sources:

Answer 16

FACs

‐ Three ADR speeds
‐ One Backup Speed.

Question 17

SPEED MONITORING FUNCTION
Backup Speed is computed from AOA, load factor, aircraft weight, GPS altitude and aircraft configuration (ailerons, spoilers, THS, and slat/flap positions). Backup Speed has an accuracy of ___ with a flight domain restricted to 280 kt / M 0.78 in stable flight conditions with speed brakes retracted.

Answer 17

+/-15 kt

Question 18

The Speed Monitoring Function consists in:

Answer 18

‐ The comparison between those four speed sources
‐ The individual monitoring of each ADR speed in order to detect icing conditions.
The speed monitoring function assigns a validity status to each speed source. This validity status can be: RELIABLE, FAULT or UNCERTAIN.

Question 19

ASSOCIATED ALERTS
As soon as the speed monitoring function detects a change in the speed validity status, the following ECAM alert can be triggered:

Answer 19

‐ NAV AIR SPD STS CHANGED
‐ NAV ALL SPD UNCERTAIN

Question 20

DIGITAL BACKUP SPEED/ALTITUDE
The DBUS enables the flight crew to fly the aircraft with

Answer 20

the backup speed and backup altitude displayed on PFD.

Question 21

The following ECAM alerts request that the flight crew to activate the DBUS when it is reliable and when at least ___ ADRs are confirmed unreliable:
‐ NAV ADR SPD STS CHANGED
‐ NAV ADR 1(2)(3) FAULT
‐ NAV ADR 1+2(1+3)(2+3) FAULT ‐ NAV ADR 1+2+3 FAULT.

Answer 21

two

Question 22

The ECAM displays NAV BKUP SPD FAULT when the

Answer 22

DBUS is failed

Question 23

DIGITAL BACKUP SPEED
DBUS activation on the PFD is indicated by:

Answer 23

‐ BKUP SPD and GPS ALT labels

‐ Amber double dash over the last digit of speed and mach
‐ Amber double dash over the last two digits of altitude.

Question 24

DIGITAL BACKUP SPEED
When at least one ADR is valid, the computation of the characteristic speeds is based on this valid ADR source.
When all ADR becomes invalid, the characteristic speeds are computed based on ___

Answer 24

the backup speed / mach and GPIRS altitude.

Question 25

DIGITAL BACKUP SPEED When NAV ALL SPD UNCERTAIN is triggered, the red and black strip does not appear as the VSW cannot be computed, however ___ remains fully functional.

Answer 25

STALL WARNING alert

Question 26

BACKUP ALTITUDE SCALE AND VERTICAL SPEED SCALE The vertical speed indication is displayed on DBUS in contrast to ___

Answer 26

BACKUP ALTITUDE SCALE on BUSS

Question 27

The Global Positioning System (GPS) is a satellite-based radio navigation aid. Worldwide, ___ satellites broadcast accurate navigation data that the aircraft use for precise determination of its position.

Answer 27

24

Question 28

The aircraft has ___ independent GPS receivers. Depending of the aircraft configuration, each receiver consists: ‐ Of a GPS Sensor Unit (GPSSU), or ‐ Is integrated in the Multi Mode Receiver (MMR). The GPS1 receiver in MMR1, and the GPS2 receiver in MMR2.

Answer 28

two

Question 29

The GPSSU or the MMR processes the received data, and transfers them to the ___. Then each ADIRU performs the GP-IRS hybrid position calculation. ___ use this hybrid position.

Answer 29

ADIRUs / FMGCs

Question 30

GPS information are available on

Answer 30

the FMS – GPS Monitor Page

Question 31

* During normal operations The GPS receiver 1 supplies the ___ and the GPS receiver 2 supplies the ___

Answer 31

ADIRU 1 and the ADIRU 3 / ADIRU 2

Question 32

STANDBY INSTRUMENTS Because of the location of the APU power on contactor in the cockpit, the APU start sequence may disturb the

Answer 32

compass reading

Question 33

DESCRIPTION OF THE ISIS The ISIS system displays the following information:

Answer 33

‐ Attitude ‐ Airspeed and mach ‐ Altitude ‐ Barometric pressure ‐ LS function ‐ Bugs

Question 34

The ISIS system must be reset after 350 h of continuous electrical supply using

Answer 34

the « ATT RST » pushbutton. The attitude indication can be reset by pressing this pushbutton for at least 2 s. The aircraft must be level during this procedure. During the reset time (approximately 10 s), the “ATT 10 s” message is displayed on the screen. This pushbutton is also used to realign the system, if excessive aircraft movement is detected during the alignment phase.

Question 35

RADIO NAV - TUNING Three modes of tuning are available :

Answer 35

1. Automatic Tuning 2. Manual Tuning 3. Back Up Tuning

Question 36

RADIO NAV - Back Up Tuning If both FMGCs fail, the flight crew can use the

Answer 36

RMPs (Radio Management Panels 1 and 2) on the pedestal for back up tuning.

Question 37

RADIO NAV - NAVAIDS - The aircraft has ___ VOR receivers. - The aircraft has ___ ILS receivers. - The aircraft has ___ DMEs. - ___ marker beacon system is included in VOR receiver 1.

Answer 37

- 2 - 2 - 2 - 1

Question 38

The aircraft has ___ radio altimeters (RA).

Answer 38

2 CAPT PFD displays the RA1 height, and the F/Os PFD displays the RA2 height. If one RA fails, both PFDs display the height from the remaining RA.

Question 39

The ___ generates a synthetic voice for radio height announcement below 2 500 ft. These announcements come through the cockpit loudspeakers, even if the SPEAKERS ARE TURNED OFF.

Answer 39

FWC

Question 40

INTERMEDIATE CALL OUT If time between two consecutive predetermined call outs exceeds a certain threshold, the present height is repeated at regular intervals. The threshold is: ‐ 11 s above 50 ft ‐ 4 s below 50 ft The repeating interval is ___

Answer 40

4 s.

Question 41

RETARD ANNOUNCEMENT The loudspeaker announces RETARD at: ‐ 20 ft, or ‐ 10 ft if autothrust is active and one autopilot is in

Answer 41

LAND mode.