Systems - ADIRU Flashcards
When would the ON BAT light illuminate?
When the ADIRU is ON but subsequent electrical power was removed and the BAT switch turned off
If the ON BAT light is on, what else is an indication of ADIRU being used by the battery?
Horn going off in the Nose Wheel well
When can the ADIRU be turned off?
Only on the ground No, below 30kts, never in flight per system logic
Can you still navigate without ADIRU?
Only to the fixes stored in the FMC previously. No LNAV/VNAV FPV no envelope protections
How can you navigate without ADIRU?
Use HDG SEL after you update it.
What bus powers ADIRU?
Main BAT HOT BUS
If ADIRU fails, what will SAARU provide?
Only data derived from the air data modules, no inertial navigation
What devices are inside the ADIRU?
Ring laser gyro’s, linear accelerometers and input processors
What components make up the ADIRS?
- ADMs
- ADIRU
- SAARU
What kind of information is provided by ADIRU?
Primary flight data, air data and inertial reference
How will you update the heading information to the SAARU?
Type in mag compass heading initially and then periodically after that.
With a SAARU-only operation, where will attitude reference be found? Or how do you know that the SAARU is healthy?
Under SAARU only operation attitude reference will remain displayed on PFD’s and you can crosscheck the values with the STBY flight instruments display
How will a SAARU-only operation affect Class II Navigation or over-water operations?
Since you have lost all navigational performance you must exit MNPS/OTS routing.
If ADIRU fails with GPS operational how do the PFD or ND look/display?
- ND will display orientation changes from HDG UP to TRK UP, ND wind direction/speed and arrow missing
- PFD will be missing flap maneuvering speeds
- AFDS modes not available are LNAV/VNAV, TOGA, LOC, GS, FPA, TRK HLD/HDG SEL (HDG available to regain autopilot after it is updated in the FMC)
- ADDITIONAL ITEMS such as autobrakes, FMC VNAV pages, FMC PERF prediction pages
If ADIRU fails and GPS is not operational, what additional items are inoperative?
ND MAP mode, active leg course and distance, direct to waypoint function, ALTN PG divert now function, navigation radio autotuning function
How long does it take for ADIRU to align?
6-15 minutes depending on where you are located in the world or if your plane has been moved during alignment
How do you align ADIRU?
Turn it off for 30 seconds, then on, put in a reference position in the FMC and wait
How often should ADIRU be reset according to Boeing?
Once every 24 hours
What happens if the aircraft is moved during the alignment process?
FMC MSG will be generated, must begin the realignment process again
How long will the SAARU provide heading information following an ADIRU failure?
Initially for 3 minutes, after must update periodically
With any EICAS message, how will you find additional information regarding the malfunction?
STATUS page or SYS synoptic pages
On initial power up what mode does ADIRU start up in?
Align mode
Is there an EICAS message?
MEMO MSG and time to remain on ND
How can you tell if the GPS is Updating the FMC?
ND has green GPS(3) also POS REF PG in the FMC
How do you power-up the SAARU?
You cannot, no controls whatsoever
