Message Name:

FMS INTERMITTENT FAILURES AND DATABASE LOADING ISSUES

• Loss of NAV DATA BASE on power-up intermittently
• Integrated Avionics Computer (IAC) loses memory
• IAC not able to hold NAV DATABASE (IAC battery voltage test passed)
• Full Loss of performance data
• Flight Management System (FMS) constantly drops off-line
• Failed to load the A/C database
• FMS intermittent failures during loading NAV database

• Integrated Avionics Computer (IAC) Battery

Advisory Wire/Service Bulletin:

• AW700-31-0473 - Integrated Avionic Computer (IAC)-No Fault Found (NFF) investigation Conclusions
• AW700-31-0647 - Batch 3.4 Software Upgrade-Availability and Update
• AW700-34-0241 - Data Loader DL-950 Loading Erratic
• AW700-34-0348 - Control Display Unit (CDU820)-Intermittent Blanking Display and No Fault Found Update

Forum Articles/Infoservice/Newsletter: None

Honeywell Service Information Letter:

• Honeywell SIL No. D201105000003 Rev 2 - NZ-2000 Navigation Computer, PN 7018879-03XXX, IC-615 Integrated Avionics Computer, PN 7017000-XXXXX, IC-800 Integrated Avionics Computer, PN 7017300 XXXXX; Flight Management System (FMS) CNTL-D and Hyperstart Procedures
• Honeywell SIL No. D201402000051 Rev 2 - Global Express P-2000XP IC-800/IC-810 Integrated Avionics Computer (IAC), Internal Battery Information and Internal Battery Maintenance
  NOTE: Operator should evaluate optional maintenance task per the Maintenance Planning Document (MPD) document for IAC Battery replacement every 15 months, where the interval can be adjusted based on operation

1. Confirm that the battery has low voltage and replace as required AMM TASK 31-41-01-960-801.
   NOTE: In service experience has shown that a low or marginal battery voltage even when not triggering any of battery messages may affect operation of the functions using holdup power listed in the Honeywell SIL D201402000051 Rev. 2.
2. Check for the following CAIMS message, to also evaluate a low battery voltage status.

• IAC 1 BATTERY FAULT
• IAC 2 BATTERY FAULT
• IAC 3 BATTERY FAULT

NOTE: A low battery warning can also be seen on the FMS CDU scratchpad.

Post Battery Replacement:

NOTE: In the event of a failure related to Navigation Database and Aircraft Database (ACDB) upload procedure/ problems, check AW700-34-0241 latest revision for further information.

Check if IAC intermittent failures are present or problems with the databases are still present:

1. Perform an HYPERSTART (Honeywell SIL No. D201105000003 Rev. 2) in order to reset IACs internal RAM. Since the battery holds up different RAMs in the IAC, the battery could be related to the corruption.
2. Field experience shows that sometimes intermittent failures have been cleared through IAC NVMs erase. The following are IMT messages associated with intermittent failures, shown in CAIMS Active Faults, that can be cleared through IAC NVMs erase:

   • "FMS 1 inop"
   • "external ascb fault"
   • "external monitor fault"
   • "SG Inop"
   • "iac/ext clk interface"
   • "IAC/LX ARINC intfc"
   • "external monitor fault"
   • "FMS-invalid-IAC fault"

NOTE:

• Prior to erasing a NVM it is always suggested to download and save its content
• The procedure that should be always followed is the AMM Task 45-45-00-970-822
• Operators should also keep in mind, that in order to avoid any sort of NVM download issues, it is recommended to start CAIMS before launching the NVM download software and to keep it open until the NVMs' download is completed