Flight Instruments Flashcards
How many Air Data Systems?
Three - two main and one standby
Powered by DC emer bus and backed up by hot emer batt bus
What inputs do the ADVs receive?
- Static air pressure
- Total air pressure
- Total air temperature
What does ADC 1 supply?
- captains instruments
- AHRS 1
- Flight Data Acquisition Unit
- GPWS system
- Pressurisation system
- Automatic flight control system
- MFCs
- Transponder
What does ADC 2 feed?
- FO’s instruments
- AHRS 2
- Flight Data Acquisition Unit
- MFCs
- Pressurisation System
- Automatic Flight Control System
- Transponder System
What powers the captains airspeed indicator?
26 V AC standby bus
What powers the FO’s ASI?
26 V AC Bus 2
What does the barber pole on the ASI indicate?
The max airspeed computed by the associated ADC
What does the fast/slow indicator on the EADI refer to ?
The airspeed but set in the airspeed indicator
What failure flags show on the ASI?
Red VMO flag - failure in VMO channel
Red OFF flag - failure on the IAS indicator and VMO channel or loss of AC power
What powers the captains altimeter?
26 VAC stby bus
What powers the FO’s altimeter
26 VAC Bus 2
What powers the FO’s altimeter
26 VAC Bus 2
When does the altitude alert light illuminate?
When the aircraft altitude is within 1000ft of selected altitude
Extinguishes when aircraft is within 250 ft of selected altitude
When will an OFF flag show on the altitude counter?
- power failure
- associated ADC failure
- erroneous info displayed
When will an OFF flag show on the altitude counter?
- power failure
- associated ADC failure
- erroneous info displayed
What powers the electrical vibrator in the standby altimeter?
DC Bus 1
What powers the VSIs?
Captain - 26VAS Stby Bus
FO - 26 VAC Bus 2
What is the VSI range?
0 - 6000 fpm
When will a VS flag be displayed on the VSI?
When there is a failure of the vertical speed indicator - the pointer will also be removed from view
Where is the TAS displayed?
On the TAS indicator located on Captain’s side
ADC selected by the ADC switch is used to calculate the TAS
What does it mean if the TAS display shows amber dashes?
The ADC is producing an invalid signal
What is the TAS display range?
68 - 600 kt
What do three amber dashes mean on the TAT indicator?
The selected ADC is calculating an invalid TAT value
What does the amber FAULT light mean above the ADC switch?
The selected ADC disagrees with the ADC selector switch position
How many AHRS systems?
Three - AHRS 1 + 2 plus a standby system
Where are the AHRUs?
(Attitude heading reference units)
The floor of the forward cargo compartment
Operational through 360 degrees of bank and 90 degrees of pitch
What powers the AHRSs?
AHRS 1 - primary is the DC emer bus, back up is DC bus 2
AHRS 2 - primary is DC bus 2, back up is DC emer bus (ground) and DC Bus 1 (flight)
Where are the flux valves located?
In each wing tip
Provide info to the associated AHRU
What does AHRS 1 supply?
- number 1 symbol generator unit
- FOs RMI
- Flight data acquisition unit
- Weather radar (only supplied with attitude info to stabilise the antenna)
What does AHRS 2 supply?
- number 2 symbol generator
- Captain’s RMI
How are the RMIs and AHRSs coupled?
Each AHRS is coupled to the opposite RMI
When will a red OFF flag show on an RMI?
In the event of a loss of the associated AHRS data or if there is an internal failure of the RMI
What does the A/ERECT fail light indicate?
Loss of TAS info
What is AHRS basic mode?
When TAS info is lost
Affected AHRS can still be erected in flight however aircraft must be in unaccelerated level flight
;Push and hold AHRS pb for 15 secs
How long does it take for the AHRS system to initialise?
3 minutes
ATT and FAIL flags will appear whilst initialising
Time remaining can be determined by pressing the respective AHRS button
Compass will decrease 1 degree per second until it shows zero
What powers the standby attitude indicator?
Primary - DC ess bus
Back up - Hot emer bat bus
What does the red and white flag mean on the standby AI?
- loss of power
- insufficient gyro speed to provide a reliable attitude indication
What happens if an SGU fails?
Either SGU can supply four CRTs if necessary
What mode are weather returns displayed?
Arc mode
What is the range of DH that can be selected?
-10 ft to 990 ft
What will the EFIS test show?
Display of all failure messages on the EFIS displays
How is the DH cleared from the EADI?
By selecting a value of zero which will remove DH and white letters
What will the radio altimeter test show?
A radio altitude of 100ft will be displayed on the EADI
What is composite mode?
EHSI is turned off and all screen information is portrayed on the EADI
What is map mode?
Waypoints are displayed on the associated EHSI
Active waypoint displayed in magenta and other waypoints in white
What can be switched on the switching panel?
- ATT/HDG
- VOR/ILS
- EFIS symbol generator
How is a failure of AHRS 1 shown?
- Removal of attitude and heading info from the EADI and EHSI
- EADI will show a red ATT FAIL message
- EHSI will display a red HDG FAIL message at the top of the EHSI
How will a VOR or ILS fail be indicated?
- EADI will display a red cross over the glideslope deviation indicator and the lateral deviation indicator
- EHSI will display red cross over the vertical deviation indicator and lateral deviation indicator and amber dashes for the course and distance indications
How is an SGU failure indicated?
- Removal of all info from the affected sides EHSI and EADI
- red cross with a red SG FAIL message
What is the EFIS COMP alert?
if an SGU detects a significant difference between the two inputs
What heading difference will trigger an alert?
More than 6 degrees angle of bank at bank angles below 6 degrees
12 degrees difference if bank angle more than 6 degrees
Amber HDG message
What pitch and roll difference will trigger an alert?
If pitch or roll differs by more thann 6 degrees, amber PIT or ROL message
If both differ by more than 6 degrees, amber ATT message
What ILS difference will trigger a warning?
Localizer - difference of more than 0.6 degrees, amber LOC message
Glideslope - difference of more than 0.2 degrees, amber GS message
If both loc and gs differ by more than 0.6 and 0.2 respectively, amber ILS message
When does the CVR and DFDR start and stop recording?
Start - when aircraft is operating under its own electrical power
(if powered by a GPU recorders are off until one engine operating)
Stop - ten minutes after the engines have been shut down
What does the CVR record?
Retains the last 30 minutes of recordings
What does the DFDR retain?
Retains the last 25 hours of recordings
When will the CVR erase button work?
- landing gear shock absorbers compressed
- parking brake set
tape completely erased by pressing and holding erase pb
What indicates a successful CVR test?
Movement of the pointer into the white band area
