CSAS/IGGS Press Drift Fault

TASK 21-58-00-810-825-A
CSAS/IGGS Press Drift Fault

1. Possible Causes

SENSOR-PRESS,CSAS [117HW]
SENSOR-PRESS MONITORING, IGGS & ASM [5YA]
FILTER-AIR [2YM]
ASM [1YM]

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	WATER - SOAPY SOLUTION

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.14CCB6)	Testing Medium-Leak Detection - Oxygen System

C. Referenced Information

REFERENCE	DESIGNATION
AMM 21-58-00-710-002	Operational Test of the Conditioned Service Air System with Bleed Air
AMM 21-58-12-000-001	Removal of the Pressure Sensor
AMM 21-58-12-400-001	Installation of the Pressure Sensor
AMM 47-10-41-920-001	D-ULPA Filter Element Replacement
AMM 47-10-43-920-001	Air Separator Module Replacement
AMM 47-41-13-000-001	Removal of the Pressure Sensor
AMM 47-41-13-400-001	Installation of the Pressure Sensor

3. Fault Confirmation
Subtask 21-58-00-810-098-A ** ON A/C NOT FOR ALL

A. Access
(1) Get access to the CSAS pressure sensor (117HW) and the IGGS pressure sensor (5YA).

Subtask 21-58-00-710-095-A ** ON A/C NOT FOR ALL

B. Test.
(1) Apply a solution of Testing Medium-Leak Detection - Oxygen System (Material No.14CCB6) or WATER - SOAPY SOLUTION to all components and ducts of the Fuel Tank Inerting System in the area between the CSAS pressure sensor (117HW) and the IGGS pressure sensor (5YA) to search for a leak.
(2) Do the operational test of the conditioned service air system with bleed air AMM 21-58-00-710-002.
(3) Do a check for leakages in the area between the CSAS pressure sensor (117HW) and the IGGS pressure sensor (5YA) while and immediately after the system test with bleed.

4. Fault Isolation
Subtask 21-58-00-810-099-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message CSAS/IGGS PRESS DRIFT:

if necessary remove a leakage by replacement of the faulty component.

(1) If the fault continues:

replace the SENSOR-PRESS,CSAS [117HW] AMM 21-58-12-000-001 and AMM 21-58-12-400-001.

(2) If the fault continues:

replace the SENSOR-PRESS MONITORING, IGGS & ASM [5YA] AMM 47-41-13-000-001 and AMM 47-41-13-400-001.

(3) If the fault continues:

do a check for blockages between the CSAS pressure sensor (117HW) and the IGGS pressure sensor (5YA).
replace the FILTER-AIR [2YM] AMM 47-10-41-920-001.

(4) If the fault continues:

replace the ASM [1YM] AMM 47-10-43-920-001.

Subtask 21-58-00-710-096-A ** ON A/C NOT FOR ALL

B. Do the test as given in the Para. 3.A.

[Rev.8 from Aug 2018] 2026.04.04 04:24:51 UTC