AIB AC downlink mesages
The DMU is part of AIDS (Aircraft Instrument Data System) on A320 family and ACMS (Aircraft Condition Monitoring System) on A330/A340. Basically, the AIDS/ACMS provides the capability to transmit reports to the ground for the following applications:
– Aircraft performance monitoring
– Engine condition monitoring
– APU health monitoring
The ATSU downlinks the following DMU reports to the ground:
+ Engine cruise report, Cruise performance report, Engine take-off report, Engine report on request,
+ Engine Trim Balance (A330/A340 only), Engine divergence report,
+ Engine start report, Engine run up report,
+ APU MES/IDLE report, APU shut down report,
+ Engine gas path advisory report, Engine mechanical advisory report,
+ Free programmable report #1, Free programmable report #2, Free programmable report #3,
+ Load report, ECS report, RAT report,
The above listed reports can be either report stored in the DMU buffer after automatic generation, or reports generated on manual request or on ATSU uplink
request.
The DMU can be programmed in order to automatically transfer reports to the ATSU as soon as they are generated. The automatic transfer depends on the
AIDS/ACMS setting. A message is considered delivered by he DMU when the ground acknowledgement is forwarded by the ATSU
The CFDIU (Centralized Fault Data Interface Unit) is part of the A320 family avionics and CMC (Central Maintenance Computer) of A330/A340 avionics.
The ATSU downlinks the following CMC/CFDIU reports to the ground:
– Post Flight Report (on ground)
– Current Flight Report (in flight)
– Real Time Failure (in flight)
– Real Time Warning (in flight)
– Bite Data Messages
– Class 3 Report (on ground) (A340/A340 only)
The CMC/CFDIU can automatically transmit the Post Flight Report (PFR) to the ATSU at the end of the flight leg. The PFR can also be transmitted on manual
command or on uplink request.
The failure messages can automatically be transmitted in real-time by the CMC/CFDIU to the ATSU. When the CMC/CFDIU report contains failure messages,
which have not been transferred yet to the ATSU, the CMC/CFDIU automatically tries to transfer the oldest one. The CMC periodically attempts to transfer this
failure message until the message is successfully downlinked until deletion.
The ECAM warning messages are automatically transmitted by the CMC/CFDIU to the ATSU with the same logic as for the failure messages.
Any BITE data messages can be manually downlinked from the CFDIU/CMC MCDU pages.
The CMC transmits the Class 3 report to the ATSU on uplink request or on manual command.
When Servicing report option is available, the CMC is able to downlink the servicing report.
The CMC transmits the Servicing Report to the ATSU:
– Automatically, at the end of the flight leg
– On uplink request
– On manual command
The AOC hosted application within ATSU creates and transmits a documentary data of the required format when requested by the CMC and when entering the ‘IN’ OOOI state.
Activations of functions in the CMC/CFDIU, i.e. automatic report transmission to the ATSU, are programmed in the ATSU. The ATSU sends periodically to the
CMC/CFDIU this information, allowing the CMC/CFDIU to know which kind of report has to be downlinked. Active functions programming concern:
– ECAM warning report
– Failure report
– Post Flight Report
– BITE data report (A330/A340 only)
(Source: AIB Publications)
