SLT Channel No Cross Talk Between SFCC1 and SFFC2. Loss of Cross Computer Link or Faulty Data

TASK 27-81-00-810-826-A
SLT Channel No Cross Talk Between SFCC1 and SFFC2. Loss of Cross Computer Link or Faulty Data

NOTE: If the SFCC identified as sending NO DATA is under MMEL or failed, this procedure is not applicable. This fault is a consequence of the failure or MMEL condition.

1. Possible Causes

SLAT/FLAP CONTR.COMP. [21CV]
SLAT/FLAP CONTR.COMP. [22CV]
aircraft wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 27-51-34-000-001	Removal of the SFCC
AMM 27-51-34-400-001	Installation of the SFCC
ASM 278108
AMM 27-84-00-710-001	Operational Test of the Slat System
AMM 31-32-00-860-006	Procedure to Get Access to the SYSTEM REPORT/TEST F/CTL Page

3. Fault Confirmation
Subtask 27-81-00-865-059-A

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	FLIGHT CONTROLS/SLT/CTL AND MONG/SYS1	5CV	B06
121VU	FLIGHT CONTROLS/SLT/CTL/SYS2	7CV	R21

Subtask 27-81-00-710-059-A

B. SFCC Reset and Initialization
(1) At the circuit breakers:
(a) Open the circuit breakers.
(b) Wait for 3 seconds and close the circuit breakers.
(c) Wait for 60 seconds and do the next step.
(2) At the MCDU set the SYSTEM REPORT/TEST FLT CTL page AMM 31-32-00-860-006:
(a) Set the page for the SFCC related to the slat channel which reported the loss of data.
(b) At the applicable SFCC1 (or SFCC2) SYSTEM STATUS SLAT page:

if the message SLT1 NO SFCC2 DATA (or SLT2 NO SFCC1 DATA) is shown, do the fault isolation procedure given in Para 4.A.
if a different message is shown, do the trouble shooting procedure related to this message.
if no message is shown , no further maintenance action is necessary.

4. Fault Isolation
Subtask 27-81-00-810-075-A

A. Procedure
(1) Interchange SFCC1 with SFCC2
AMM 27-51-34-000-001 and AMM 27-51-34-400-001.
(2) Do the test given in Para. 3.B.(2):

if the message stays in the same system, do step (5)
if the message moves to the opposite system, do the next step.

(3) Replace the SLAT/FLAP CONTR.COMP. [21CV] or SLAT/FLAP CONTR.COMP. [22CV] in the slat channel which reported the loss of data AMM 27-51-34-000-001 and AMM 27-51-34-400-001:
(a) Make sure that you install the serviceable SFCC to its initial position.
(b) If the fault continues, do the next step.
(4) Replace the opposite SFCC to that replaced in step (3):

if the fault continues, do the next step.

(5) If step (2) was your last step:

Install the SFCCs to their initial positions.

Do a check and repair the aircraft wiring between SFCC1 and SFCC2 ASM 278108.
(6) Do the operational test of the slat system AMM 27-84-00-710-001.

[Rev.8 from Aug 2018] 2026.04.04 04:27:49 UTC