W DOC AIRBUS | TSM A320F

Slat System Runaway

TASK 27-81-00-810-814-A
Slat System Runaway

1. Possible Causes
  • Slat Transmission System
  • SLAT-PCU [6001CM]
  • FPPU-SLAT [28CV]
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
98D27804012000
1
GAGE-RIGGING
 B. Referenced Information
REFERENCE
DESIGNATION
AMM 27-80-00-866-008
Manual Retraction of the Slats
AMM 27-80-00-869-004
Reset of the Wing Tip Brake (WTB) of the Slat System on the Ground
AMM 27-81-00-820-001
Manual Adjustment of the Position Pick-Off Units
AMM 27-81-19-000-001
Removal of the Feed Back Position Pick-Off Unit
AMM 27-81-19-400-001
Installation of the Feed Back Position Pick-Off Unit
AMM 27-84-00-200-001
Detailed Visual Inspection of the Slat Transmission System
AMM 27-84-00-710-001
Operational Test of the Slat System
AMM 27-84-51-000-001
Removal of the Power Control Unit of the Slat System
AMM 27-84-51-400-001
Installation of the Power Control Unit of the Slat System
3. Fault Confirmation
Subtask 27-81-00-730-051-A
A. Analysis
NOTE: 'Runaway' is a position difference between the two APPU's and the FPPU.
   (1) Get access to the MENU MODE and set it to SFCC 1 or SFCC 2.
     (a) Go to the submenu SYSTEM DATA SLAT.
     (b) Press the line key 1L to set the PPU page.
NOTE: The SFCC transmits the LH and RH APPU and the FPPU data page(s) to the CFDS. Every 5 seconds the data of the APPU DATA page(s) will be refreshed.
     (c) In the TSM:
Refer to page block 301 (TABLE 2 and TABLE 3). The LH APPU, the FPPU and RH APPU synchro angles are shown as a decimal value.
NOTE: A difference of more than 5.2 degrees generates a runaway fault message.
     (d) If there is this difference between the LH APPU, the FPPU and RH APPU, do the fault isolation.
4. Fault Isolation
Subtask 27-81-00-810-063-A
A. Procedure
   (1) Do the reset of the wing tip brakes AMM 27-80-00-869-004.
   (2) Do the detailed inspection of the Slat Transmission System , AMM 27-84-00-200-001 up to the T-gearbox.
     (a) Repair/correct any failure found (Ref. AMM chap. 27).
   (3) Do the operational test of the slat system AMM 27-84-00-710-001.
   (4) Set the CFDS MENU MODE and access the SYSTEM STATUS SLAT and make sure that NO FAULTS is shown.
   (5) Do the detailed inspection of the SLAT-PCU [6001CM] AMM 27-84-00-200-001.
   (6) If no fault is found, do a check of the FPPU zero datum mark AMM 27-81-00-820-001.
     (a) If the zero datum mark is not aligned, remove the FPPU AMM 27-81-19-000-001,
  • visually examine the PCU mounting interface,
  • visually examine the FPPU for signs of water thru the sight glass and the input shaft for visible dent.
     (b) If the FPPU is found in good condition, do the steps that follow:
       1 With the FPPU not installed on the defective wing:
  • Do the manual retraction of the slats on the left and right wing AMM 27-80-00-866-008.
  • Put the 98D27804012000 GAGE-RIGGING between the track stop and the lower forward roller at each track 1.
  • Make sure that the 98D27804012000 GAGE-RIGGING contacts the track stop and the lower forward roller.
NOTE: In this condition it is not necessary to record the PPU values before manual extension.
       2 Do the manual adjustment of the FPPU AMM 27-81-00-820-001.
  • If you feel frictions while turning the FPPU input shaft, replace the FPPU. AMM 27-81-19-400-001
  • If you feel no frictions, install the old FPPU-SLAT [28CV] again.
   (7) Before the operational test:
     (a) Do the operational test of the slat system AMM 27-84-00-710-001.
   (8) If fault continues, replace the SLAT-PCU [6001CM] , AMM 27-84-51-000-001 and AMM 27-84-51-400-001.
5. Close-up
Subtask 27-81-00-942-063-A
A. Remove the ground support and maintenance equipment, the special and standard tools and all other items.
Subtask 27-81-00-860-064-A
B. Put the aircraft back to its initial configuration.
[Rev.8 from Aug 2018] 2026.04.04 04:27:48 UTC
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