Pack 1 Flow Control Valve (Pack 1 Flow Control Unit) Fault
TASK 21-51-00-810-803-A
Pack 1 Flow Control Valve (Pack 1 Flow Control Unit) Fault
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 21-51-00-710-054-A
Subtask 21-51-00-810-052-A
Subtask 21-51-00-860-052-A
[Rev.8 from Aug 2018]
2026.04.04 04:24:46 UTC
Pack 1 Flow Control Valve (Pack 1 Flow Control Unit) Fault
1. Possible Causes
- P1 FLOW CTL VALVE [11HB]
- FLOW CTL UNIT - PACK 1 [23HB]
- RELAY-L PACK CLOSE [13HB]
- RELAY-DISAGREE (L FCV) [15HB]
- BOARD-ANN LT TEST & INTFC [8LP]
- P/BSW-AIR COND/PACK 1 [7HB]
- RELAY-ENGINE START [17HB]
- RELAY-RAM AIR CLOSE CTL [3HZ]
- RELAY-ENGINE START [16HB]
- P1 CONTROLLER [7HH]
- CONT-AIR COND SYSTEM 1 [47HH]
- wiring
- REHEATER [10HM3]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 21-51-00-200-001 | Delta P Sense Lines Torque Check and Inspection |
| AMM 21-51-00-710-002 | Operational Test of the Flow Control and Indicating System |
| ASM 215101 | |
| ASM 215102 | |
| AWM 215104 | |
| AMM 21-51-51-000-001 | Removal of the Pack Flow-Control Valve/ Pack Flow-Control Unit |
| AMM 21-51-51-400-001 | Installation of the Pack Flow-Control Valve/ Pack Flow-Control Unit |
| AMM 21-52-31-000-001 | Removal of the Reheater |
| AMM 21-52-31-400-001 | Installation of the Reheater |
| AMM 21-61-00-710-001 | Operational Test of the Pack Temperature-Control System |
| AMM 21-61-34-000-001 | Removal of the Pack Controller |
| AMM 21-61-34-000-002 | Removal of the Air-Conditioning System Controller |
| AMM 21-61-34-400-001 | Installation of the Pack Controller |
| AMM 21-61-34-400-002 | Installation of the Air-Conditioning System Controller |
| AMM 73-25-34-710-040 | Operational Test of the Engine Interface Unit |
| AMM 73-25-34-710-043 | Operational Test of the Engine Interface Unit |
Subtask 21-51-00-710-054-A
A. Test
(1) Do the operational test of the flow control and indication system AMM 21-51-00-710-002.
(2) Do the operational test of the pack temperature-control system AMM 21-61-00-710-001.
4. Fault Isolation(1) Do the operational test of the flow control and indication system AMM 21-51-00-710-002.
(2) Do the operational test of the pack temperature-control system AMM 21-61-00-710-001.
Subtask 21-51-00-810-052-A
A. If the test is OK, no other maintenance action is necessary.
Subtask 21-51-00-810-053-B ** ON A/C NOT FOR ALL B. If the test confirms the fault:
Subtask 21-51-00-810-053-C ** ON A/C NOT FOR ALL - replace the P1 FLOW CTL VALVE [11HB] (referred to as FCV (11HB)) AMM 21-51-51-000-001 and AMM 21-51-51-400-001.
B. If the test confirms the fault:
Subtask 21-51-00-810-089-A ** ON A/C NOT FOR ALL Subtask 21-51-00-810-072-A ** ON A/C NOT FOR ALL - replace the FLOW CTL UNIT - PACK 1 [23HB] AMM 21-51-51-000-001 and AMM 21-51-51-400-001.
D. If the fault continues:
(5) If the fault continues:
Subtask 21-51-00-810-081-A ** ON A/C NOT FOR ALL - do a check of the RELAY-L PACK CLOSE [13HB] and replace it if necessary ASM 215102.
- do a check of the RELAY-DISAGREE (L FCV) [15HB] and replace it if necessary ASM 215102.
- do a check of the BOARD-ANN LT TEST & INTFC [8LP] and replace it if necessary ASM 215102.
- do a check of the P/BSW-AIR COND/PACK 1 [7HB] and replace it if necessary ASM 215102.
- do the operational test of the engine interface unit (1KS1) AMM 73-25-34-710-040.
(5) If the fault continues:
- do a check of the RELAY-ENGINE START [17HB] and replace it if necessary ASM 215102.
- do a check of the RELAY-RAM AIR CLOSE CTL [3HZ] and replace it if necessary ASM 215102.
- do a check of the RELAY-ENGINE START [16HB] and replace it if necessary ASM 215102.
- replace the P1 CONTROLLER [7HH] AMM 21-61-34-000-001 and AMM 21-61-34-400-001.
E. If the fault continues:
Subtask 21-51-00-810-072-B ** ON A/C NOT FOR ALL - do a check and repair the wiring ASM 215101 between:
- the FCV (11HB) and the PC (7HH),
- the FCV (11HB) and GND,
- the RELAY (13HB) and the FCV (11HB),
- the RELAY (15HB) and the FCV (11HB) and,
- the RELAY (15HB) and the PC (7HH).
- do a check and repair the wiring AWM 215104 between:
- the circuit connection 209VT connector Y and the PC (7HH) connector AB pin 7A,
- the circuit connection 209VT connector P and RELAY (15HB) connector A pin A2.
- replace the REHEATER [10HM3] AMM 21-52-31-000-001 and AMM 21-52-31-400-001.
F. If the fault continues:
(3) If the fault continues:
Subtask 21-51-00-810-081-B ** ON A/C NOT FOR ALL - do a check of the BOARD-ANN LT TEST & INTFC [8LP] and replace it if necessary ASM 215102.
- do a check of the P/BSW-AIR COND/PACK 1 [7HB] and replace it if necessary ASM 215102.
- do the operational test of the engine interface unit (1KS1) AMM 73-25-34-710-043.
(3) If the fault continues:
- do a check of the RELAY-RAM AIR CLOSE CTL [3HZ] and replace it if necessary ASM 215102.
- replace the CONT-AIR COND SYSTEM 1 [47HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
G. If the fault continues:
Subtask 21-51-00-710-055-A - do a check and repair the wiring ASM 215102 between:
- the FCU1 (23HB) and the ACSC1 (47HH) and,
- the FCU1 (23HB) and GND.
- replace the REHEATER [10HM3] AMM 21-52-31-000-001 and AMM 21-52-31-400-001.
H. Do the test as given in the Para. 3.A.
5. Close-upSubtask 21-51-00-860-052-A
A. Put the aircraft back to its initial configuration.