The Airbus A320 has an onboard maintenance system called the Centralized Fault Display System (CFDS). This system obtains and stores messages transmitted by the connected system BITEs or by the Flight Warning Computer (Warning and Caution titles), detailing the maintenance phases.

The CFDS presents maintenance reports in the form of:

  • Last leg report
  • Last leg ECAM report
  • Previous leg report
  • Avionics status
  • System report test (BITE Test)
  • Post-flight report

In this post, we will focus on all the BITE tests and system reports available through MCDU under the “System Report/Test” option.

Learn More: Maintenance Concept of Airbus A320 Family Aircraft

CFDS

The CFDS (Centralized Fault Display System) is a centralized maintenance aid system which gives the maintenance engineers a means to read the maintenance information related to most of the aircraft systems and to initiate the tests of these systems from the cockpit. The main computer in the CFDS is the CFDIU (Centralized Fault Display Interface Unit).

The CFDIU computer is connected to most of the electronic systems (BITE) of the aircraft and stores failure information from these systems in memory. It also serves to initialize tests in each system. The MCDUs are control and display units. They serve to dialogue either with the CFDIU or with a particular aircraft system (via the CFDIU) to display failure information or to initialize tests. The printer provides print-outs of the various maintenance reports available.

BITE Test

Bite test is part of onboard maintenance that helps maintenance personnel diagnose faults following a crew complaint.

The interactive mode test is available only during ground operation. You can manually start the test from the System/Test page on the Multipurpose Control and Display Unit (MCDU). Interactive mode, also called menu mode, is the mode in which the individual is allowed to process certain tests on the system using the MCDU and controls of the cockpit.

Each system includes a Built-In-Test Equipment (BITE) used for detection and isolation of faulty equipment. A Centralized Fault Display Interface Unit (CFDIU) acquires and processes (completes, correlates, memorizes, and presents) the data transmitted by the BITEs and the warnings that have originated the crew complaint. The result of fault diagnosis is displayed through MCDU.

SYSTEM REPORT/TEST

Here is a list of all the tests/reports available through MCDU.

A320 SYSTEM REPORT/TEST PAGE 1
PAGE 1
A320 SYSTEM REPORT/TEST PAGE 2
PAGE 2

AIR COND

  • CPC 1 > LLR, PLR, LRU IDENT, TEST/CALIB, CLASS 3
  • CPC 2 > LLR, PLR, LRU IDENT, TEST/CALIB, CLASS 3
  • TEMP CTL > LLR, PLR, LRU IDENT, TSD, CLASS 3, TEST, GND REP, SYS DATA
  • AEVC > LLR, TEST, CLASS 3
  • AFT CHC > LLR, PLR, LRU IDENT, LL CLASS 3, GND REP
  • FWD CHC > LLR, PLR, LRU IDENT, LL CLASS 3, GND REP
  • CSAS/IGGS > LLR, PLR, LRU IDENT, GND REP, TSD, CLASS 3, TEST, SPECIFIC DATA

AFS

  • LLR
  • PLR
  • TSD
  • GROUND SCAN
  • AFS TEST
  • LRU IDENT
  • LAND TEST
  • WINDSHEAR TEST

COM

  • AMU > LLR, PLR, LRU IDENT, TSD, TEST, GND REP
  • RMP 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • RMP 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • RMP 3 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • CIDS 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TESTS, EPSU BAT CAP TEST, OP TESTS, GND REP, SYS CONFIG
  • CIDS 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TESTS, EPSU BAT CAP TEST, OP TESTS, GND REP, SYS CONFIG
  • HF 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • HF 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • VHF 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP, SPECIFIC DATA
  • VHF 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP, SPECIFIC DATA
  • VHF 3 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP, SPECIFIC DATA
  • SDU

ELEC

  • AC GEN > LLR, PLR, LRU IDENT, TSD, CLASS 3, SYS TEST, GND REP, SPECIFIC DATA
  • GCU EMER > TEST
  • BCL 1 > LLR, TEST, CLASS 3
  • BCL 2 > LLR, TEST, CLASS 3
  • TR 1 > RESET
  • TR 2 > RESET
  • TR 3 > RESET

FIRE PROT

  • FDU 1 > LLR, TEST, CLASS 3
  • FDU 2 > LLR, TEST, CLASS 3
  • FDU APU > LLR, TEST, CLASS 3
  • SDCU

F/CTL

  • EFCS 1 > LLR, PLR, LRU IDENT, GND SCAN, CLASS 3, MEMORY, TEST
  • EFCS 2 > LLR, PLR, LRU IDENT, GND SCAN, CLASS 3, MEMORY, TEST
  • SFCC 1 : SLT/FLP > LLR, PLR, LRU IDENT, SYS STS, CLASS 3, TEST/RESET, SYS DATA, TSD, ON GND FAULTS
  • SFCC 2 : SLT/FLP > LLR, PLR, LRU IDENT, SYS STS, CLASS 3, TEST/RESET, SYS DATA, TSD, ON GND FAULTS

FUEL

  • LLR
  • PLR
  • LRU IDENT
  • CLASS 3
  • SELECT CHANNEL 1 / 2

ICE & RAIN

  • WHC 1 > LLR, TEST, CLASS 3
  • WHC 2 > LLR, TEST, CLASS 3
  • PHC 1 > LLR, TEST, CLASS 3
  • PHC 2 > LLR, TEST, CLASS 3
  • PHC 3 > LLR, TEST, CLASS 3
  • WING ANTI ICE [THRU ECS] (CAB TEMP CONT) > LLR, PLR, LRU IDENT, TSD, CLASS 3, TEST, GND REP, SYS DATA

INST

  • ECAM 1 > LLR, PLR, LRU IDENT, GND SCAN, CLASS 3, SYS CONFIG, OEB DB
  • ECAM 2 > LLR, PLR, LRU IDENT, GND SCAN, CLASS 3, SYS CONFIG, OEB DB
  • FDIU > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP, SPECIFIC DATA
  • DLRB/DLS
  • CFDIU > LLR, LRU IDENT, GND SCAN, PWR UP TEST
  • EIS 1 (DMC 1) > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, SWTG/BUS/DU TESTS, GND REP, PIN PROG/STATUS AND XLOAD
  • EIS 2 (DMC 2) > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, SWTG/BUS/DU TESTS, GND REP, PIN PROG/STATUS AND XLOAD
  • EIS 3 (DMC 3) > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, SWTG/BUS/DU TESTS, GND REP, PIN PROG/STATUS AND XLOAD
  • DMU (AIDS) > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP, SOFTWARE LOAD STATUS
  • PRINTER

L/G

  • LGCIU 1 > LLR, PLR, LRU IDENT, TSD, GND SCAN, TEST, L/G SIMULATION
  • LGCIU 2 > LLR, PLR, LRU IDENT, TSD, GND SCAN, TEST, L/G SIMULATION
  • BSCU 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TESTS, GND REP, SPECIFIC DATA
  • BSCU 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TESTS, GND REP, SPECIFIC DATA
  • TPIS > LLR, PLR, LRU IDENT, REF PR, TEST, GND FAULTS, TSD

NAV

  • ADR 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, OUTPUT TESTS, GND REP, INPUT STATUS
  • IR 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, INTERFACE TEST, GND REP, INPUT STATUS
  • ADR 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, OUTPUT TESTS, GND REP, INPUT STATUS
  • IR 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, INTERFACE TEST, GND REP, INPUT STATUS
  • ADR 3 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, OUTPUT TESTS, GND REP, INPUT STATUS
  • IR 3 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, INTERFACE TEST, GND REP, INPUT STATUS
  • RA 1 > LLR, PLR, LRU IDENT, TSD, SYS TEST, RAMP TEST, GND REP
  • RA 2 > LLR, PLR, LRU IDENT, TSD, SYS TEST, RAMP TEST, GND REP
  • DME 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • DME 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • MMR 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, GND REP
  • MMR 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, SYS TEST, GND REP
  • VOR 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • VOR 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • RADAR 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • ADF 1 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • ADF 2 > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP
  • ATC 1 > LLR, PLR, LRU IDENT, TSD, CLASS 3, TEST, GND REP, DISCRETE CONFIG
  • ATC 2 > LLR, PLR, LRU IDENT, TSD, CLASS 3, TEST, GND REP, DISCRETE CONFIG
  • HUD
  • GPWC > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP, CURRENT STATUS
  • GPSSU 1
  • TCAS > LLR, PLR, LRU IDENT, GND SCAN, TSD, CLASS 3, TEST, GND REP, DISCRETE CONFIG

PNEU

  • BMC 1 > LLR, PLR, LRU IDENT, CURRENT DATA, CLASS 3, TEST
  • BMC 2 > LLR, PLR, LRU IDENT, CURRENT DATA, CLASS 3, TEST

APU

  • LLR
  • PLR
  • LRU IDENT
  • GND SCAN
  • TSD
  • CLASS 3
  • TEST
  • SHUTDOWNS
  • SERVICE DATA

ENG

  • EIU 1 > LLR, PLR, LRU IDENT, CLASS 3, GND SCAN
  • EIU 2 > LLR, PLR, LRU IDENT, CLASS 3, GND SCAN
  • FADEC 1A > LLR, PLR, LRU IDENT, TSD, CLASS 3, IGN TEST, T/R TEST, FADEC TEST, SCHED MAINT REPORT, SPECIFIC DATA
  • FADEC 2A > LLR, PLR, LRU IDENT, TSD, CLASS 3, IGN TEST, T/R TEST, FADEC TEST, SCHED MAINT REPORT, SPECIFIC DATA
  • FADEC 1B > LLR, PLR, LRU IDENT, TSD, CLASS 3, IGN TEST, T/R TEST, FADEC TEST, SCHED MAINT REPORT, SPECIFIC DATA
  • FADEC 2B > LLR, PLR, LRU IDENT, TSD, CLASS 3, IGN TEST, T/R TEST, FADEC TEST, SCHED MAINT REPORT, SPECIFIC DATA
  • EVMU > LLR, PLR, LRU IDENT, CLASS 3, TEST

INERTING

  • CSAS/IGGS > LLR, PLR, LRU IDENT, GND REP, TSD, CLASS 3, TEST, SPECIFIC DATA

The operator has called up menus of the selected systems :

  • LAST or PREVIOUS LEG REPORT presents the list of Line-Replaceable Units (LRUs) affected by a failure.
  • LRU IDENTIFICATION contains the part numbers of all LRUs in the system.
  • GND SCANNING runs the flight monitoring on the ground and indicates the faulty LRU.
  • CLASS 3 FAULTS lists class 3 faults detected by the system during the last flight leg.
  • SYSTEM CONFIGURATION presents the system configuration in a digital form.
AviationHunt Team

Our team at AviationHunt is a group of aviation experts and enthusiasts. We aim to provide aviation insights, technical notes, best aircraft maintenance practices, and aviation safety tips.