NAVIGATION & DISPLAY PANEL

Question 1

VHF NAV Transfer Switch

• 3 positions -

BOTH ON 1

NORMAL

BOTH ON 2

Answer 1

• this switch changes the source of the data that the DEUs use for the Nav Displays (ND).
• transfers: DME, ILS, VOR and MCP Course information
• enables selection of the opposite vhf nav receiver/MMR if it fails

BOTH ON 1:

• DEUs use MMR 1 as the source for CAPT & FO displays
• if neither AP’s are in CMD and both FD switches are ON - in this position FD B will bias out of view
• FO instruments are referenced to CAPT selected course and Nav receiver

NORMAL:

• MMR 1 drives Capts display and MMR 2 drives FO display

BOTH ON 2:

• DEUs use MMR 2 as the source for CAPT & FO displays
• if neither AP’s are in CMD and both FD switches are ON - in this position FD A will bias out of view
• CAPT instruments are referenced to FO selected course and Nav receiver

Notes:

• if in either BOTH ON 1 (or 2) - the RMI needles will not transfer (ie if both on 2, the narrow VOR needles on both RMIs are inop. - has nothing to do with ADFs

CAUTION:

• the DFCS (digital flt control sys) can’t use VOR/ILS data that is not shown on the displays.
  
  • so, when the AP is engaged - the VHF Nav control MUST MATCH the primary AP that is ENGAGED for proper ILS/VOR ops
  • CMD A uses VHF Nav 1 - CMD B uses VHF Nav 2

Question 2

IRS Transfer Switch

• 3 position -

BOTH ON L

NORMAL

BOTH ON R

Answer 2

• enables selection of the opposite IRS (ADIRU) in the event of attitude or compass failures
• moving this switch will kick off the AP
• when selected to either BOTH ON L (or R) - either AP can be engaged (but should use the unfaulted one)
• when AP is ENGAGED - the YD will DISENGAGE and CANNOT BE RECONNECTED until AP is disengaged

BOTH ON L:

• switches the gyro source (ATT and HDG) to the left IRS

NORMAL:

• Default setting. Left flight instrument source - LEFT ADIRU and Right inst source - RIGHT ADIRU

BOTH ON R:

• switches the gyro source (ATT and HDG) to the right IRS

Note:

• when this switch is NOT in the NORMAL position - you will get a ‘INSTR SWITCH’ message which tells you that CAPT and FO are using same ADIRU source
• this light is on the LOWER RIGHT of BOTH PFD’s

Question 3

FMC Source Select Switch

• 3 position -

BOTH ON L

NORMAL

BOTH ON R

Answer 3

• Dual FMCs
• when either BOTH ON L (or R) selected the second FMC will become a navigation monitor - info will still be sent to the FMC
• Moving this switch - causes LNAV to DISENGAGE (revert to CWS ROLL) and VNAV disengages (revert to ALT HOLD)

BOTH ON L:

• Selects Left FMC for all FMC operations
• Right Map will show ‘FMC L’ light

NORMAL:

• LEFT FMC -
  
  • controls CDUs
  • provides inputs to Auto Throttle
• RIGHT FMC -
  
  • dual operation enabled (ie Right is synced to the Left)
• Maps display composite info from BOTH FMCs
• each FMC provides it own inputs to its own:
  
  • FCC
  • MAP
  • Auto Pilot
  • Nav / Radio tuning

BOTH ON R:

• Selects RIGHT FMC for all FMC operations
• LEFT Map will show ‘FMC R’ light

Question 4

DISPLAYS ‘SOURCE’ Switch

• 3 position -

ALL ON 1

AUTO

ALL ON 2

Answer 4

• controls the 2 DEUs (all DUs can be driven by either one or both DEUs)
• controls which DEU sends info to which DU
• normally this is used on the ground for maint purposes
• under airspeed tape a [CDS FAULT] light might illuminate (non-dispatchable)

ALL ON 1:

• selects CAPTs DEU (#1 deu) to drive all 6 displays
• ‘DSPLY SOURCE’ light on BOTH PFDs below the speed tape

AUTO:

• DEU 1 drives Capt side DUs and Upper DU
• DEU 2 drives FO side DUs and Lower DU
• provides automatic switching from both to one if there is a single DEU failure

ALL ON 2:

• selects FOs DEU (#2 deu) to drive all 6 displays
• ‘DSPLY SOURCE’ light on BOTH PFDs below the speed tape

Question 5

DISPLAYS - CONTROL PANEL Switch

• 3 position -

BOTH ON 1

NORMAL

BOTH ON 2

Answer 5

• normally these switches are used on the ground for maint purposes
• might get [DISPLAYS CONTROL PANEL] light - due to invalid EFIS panel data

BOTH ON 1:

• both CAPT & FO displays are controlled by the CAPTs EFIS panel

NORMAL:

• left EFIS panel controls CAPT displays and right EFIS panel controls FOs displays

BOTH ON 2:

• both CAPT & FO displays are controlled by the FOs EFIS panel