(b) Correlation principle
1 Correlation between fault messages:
_ In order to limit the number of fault messages printed on the PFR and to give the line mechanic only the root cause of a fault, the CFDIU correlates the fault messages. This correlation is based on the GMT and the ATA chapter of the received fault messages.
2 Correlation between fault message and ECAM warning or
_ Maintenance Status: This correlation has to be performed by the line mechanic. The ATA Chapter and the GMT have to be used (general case). If a fault appears and disappears several times during the same flight leg, the corresponding fault message is transmitted only at the first detection, but the ECAM warning (for a Class 1 fault) or the Maintenance Status (for a Class 2 fault) is displayed every time in the cockpit and transmitted every time to the CFDIU. Therefore, it is possible to find in the PFR several times the same ECAM warning or Maintenance Status but only one fault message.
Example:
ECAM WARNING MESSAGES GMT PH ATA 1000 06 31-00 DAR(3) 1030 06 21-31 CAB PR SYS 2 FAULT 1045 06 31-00 DAR
FAILURE MESSAGES
GMT PH ATA SOURCE IDENT.
1000 06 31-36-52 DAR DMU
1030 06 21-31-34 PRESS CONTR 2 CPC2
The DAR fails several times during the flight. The figure (3) displayed after the Maintenance Status "DAR" means that this Maintenance Status was sent 3 consecutive times to the CFDIU for PFR recording. In order to prevent the recording of 3 "DAR" messages, the "occurence counter" has been activated, and only the fault message related to the first occurrence of the DAR fault is recorded (GMT = 1000). But as a warning "CAB PR SYS 2 FAULT" has been recorded (GMT = 1030), followed by a new "DAR" Maintenance Status (GMT=1045), then in this case the "occurence counter" is reset. If the warning "CAB PR SYS 2 FAULT" would have not been recorded, the "DAR" message would have been recorded at GMT=1000 with a counter set to 4.
(c) An ECAM warning or a Maintenance Status can be associated with a system only shown as an identifier in the PFR, because it is not the root cause of the fault.
EFF : ALL
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R
CES Example:
ECAM WARNING MESSAGES GMT PH ATA 0844 06 34-00 NAV RA 2 FAULT 0844 06 27-00 F/CTL
FAILURE MESSAGES
GMT PH ATA SOURCE IDENT.
0844 06 34-42-33 NO RA2 DATA CFDS EFCS 1
EFCS 2
ECAM 1
ECAM 2
EIS 1
EIS 2
There is a Radio Altimeter 2 fault.
The RA2 is really faulty and is not able to send a fault message.
The users of the RA2 signals detect the fault (CFDS, EFCS, ECAM,
EIS). For the EFCS, the loss of the RA2 is a class 2 fault. The
associated Maintenance Status is available (F/CTL).
The installation of a new RA2 on the aircraft will eliminate the
ECAM warning and the Maintenance Status.
NOTE : The number of identifiers is limited to 6. If more than 6
____ are correlated, the CFDIU keeps only the first six systems received. The remaining are ignored. It is therefore theorically possible to have an ECAM warning or a Maintenance Status without any indication on the associated system in the FAILURE MESSAGES part.
(2) 2nd group: reports available via the SYSTEM REPORT/TEST
The manual test function is the main function of the CFDS manual
operating mode.
The purpose is to be able to test on the ground, the maximum number
of components, i.e. the integrity of the computer managing the test,
the system LRUs and the validity of the external signals used by the
system with a single test.
(a) Various types of tests (Ref. Fig. 016) Nonetheless, in order to optimize the test function and better satisfy operator requirements, certain adaptations have been introduced:
-
To limit system complexity and their BITE, the test function does not always fully cover complete system integrity. In the TSM with each maintenance message, the test or the procedure will be indicated making it possible to recheck the component on the ground
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本文鏈接地址：A320 Trouble Shooting Manual 排故手冊 介紹 2(16)
