W DOC AIRBUS | AMM A320F

Functional Test of the Integrated Standby Instrument System (ISIS) Indicator

TASK 34-22-25-720-001-A
Functional Test of the Integrated Standby Instrument System (ISIS) Indicator

ZONE: 120
ZONE: 210
1. Reason for the Job
Self explanatory
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
AR
SAFETY CLIP - CIRCUIT BREAKER
ALT34100001
1
PITOT AND STATIC TEST SET
 B. Work Zones and Access Panels
ZONE/ACCESS
ZONE DESCRIPTION
120
AVIONICS COMPARTMENT
210
CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD
 C. Referenced Information
REFERENCE
DESIGNATION
TASK 12-24-34-600-001-A
Bleeding of the Standby Air Data System
TASK 24-41-00-861-002-A
Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01
Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02
Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A
De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01
De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02
De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 29-00-00-864-001-A
Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
F Pitot and Static Test Set
3. Job Set-up
WARNING: MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.
Subtask 34-22-25-860-055-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
   (1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
   (2) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
Subtask 34-22-25-865-055-A ** ON A/C NOT FOR ALL
WARNING: OPEN CIRCUIT BREAKER 7XE. THIS WILL PREVENT A POSSIBLE DEPLOYMENT OF THE RAT IF THE MAIN AC BUSBARS 1XP AND 2XP BECOME ISOLATED.
B. Open, safety and tag this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VUANTI ICE/PROBES/AOA/14DA1D04
49VUANTI ICE/PROBES/PITOT/13DA1D02
105VUELEC/CSM/G /EV AUTO/SPLY7XEC01
122VUANTI ICE/PROBES/2/PITOT3DA2Y14
122VUANTI ICE/PROBES/2/AOA4DA2Y13
122VUANTI ICE/PROBES/2/STATIC5DA2Y11
122VUANTI ICE/PROBES/3/PITOT3DA3Z16
122VUANTI ICE/PROBES/3/AOA4DA3Z15
122VUANTI ICE/PROBES/3/STATIC5DA3Z14
122VUANTI ICE/PROBES/1/STATIC5DA1Z13
Subtask 34-22-25-865-056-A ** ON A/C NOT FOR ALL
C. Make sure that this(these) circuit breaker(s) is(are) closed:
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VUNAV/STBY/INST5FNF12
105VUNAV/STBY/INST/BAT23FNJ01
Subtask 34-22-25-860-056-A ** ON A/C NOT FOR ALL
D. Connection of the Ground Pressure Generator
CAUTION: TO PREVENT DAMAGE TO INSTRUMENTS, OBEY THESE PRECAUTIONS WHEN YOU DO THE TEST:
  • THE PRESSURES SET MUST NOT BE MORE THAN 1050 hPa (31 in Hg) OR LESS THAN 115 hPa (3.39 in Hg)
  • CHANGES IN STATIC AND TOTAL PRESSURES MUST NOT BE MORE THAN 6000 FEET/MINUTE
  • DO NOT SUDDENLY OPEN LINES TO AMBIENT AIR WHILE THE PRESSURE GENERATOR IS CONNECTED.
CAUTION: THE TOTAL PRESSURE IN THE PITOT SYSTEM MUST NEVER BE LESS THAN THE STATIC PRESSURE. THE DIFFERENCE BETWEEN THE PITOT AND THE STATIC PRESSURE CIRCUITS MUST NEVER BE MORE THAN 368 hPa (10.86 in Hg).
   (1) Remove the slip on covers from left and right standby static-probes 7DA3, 8DA3 and standby pitot-probe 9DA3.
   (2) Drain the standby air-data system (Ref. AMM TASK 12-24-34-600-001).
   (3) Connect the ALT34100001 PITOT AND STATIC TEST SET to the left or right standby static-probe with the ADAPTER STATIC PROBE.
F Pitot and Static Test Set ** ON A/C NOT FOR ALL
   (4) Connect the ALT34100001 PITOT AND STATIC TEST SET to the standby pitot probe with the ADAPTER PITOT PROBE.
F Pitot and Static Test Set ** ON A/C NOT FOR ALL
   (5) Seal the opposite standby static-probe with the ADAPTER STATIC COVER.
   (6) Start the ground pressure generator and set a static pressure of 1013 hPa (29.91 in.Hg).
4. Procedure
Subtask 34-22-25-720-051-A ** ON A/C NOT FOR ALL
A. Test of the Standby Airspeed and Altimeter Functions of the ISIS Indicator
NOTE: If the "CAB PR EXCES RESIDUAL PR" warning message comes into view during this test, you can ignore this message.
ACTION
RESULT
On the ground pressure generator:
On the center instrument panel 401VU:

  • Set a static pressure of 314.8 hPa (29,000 ft).

  • Set an impact pressure of 200.1 hPa (or total pressure of 514.9 hPa) (340 Kts).
  • Make sure that the ISIS indicator shows 29,000 ft (+ or - 180 ft).
  • Make sure that the ISIS indicator shows 340 Kts (+ or - 5 Kts).
  • Set a static pressure of 465.6 hPa (20,000 ft).

  • Set an impact pressure of 200.1 hPa (or total pressure of 665.7 hPa) (340 Kts).
  • Make sure that the ISIS indicator shows 20,000 ft (+ or - 150 ft).
  • Make sure that the ISIS indicator shows 340 Kts (+ or - 5 Kts).
  • Set a static pressure of 571.8 hPa (15,000 ft).

  • Set an impact pressure of 153.5 hPa (or total pressure of 725.3 hPa) (300 Kts).
  • Make sure that the ISIS indicator shows 15,000 ft (+ or - 105 ft).
  • Make sure that the ISIS indicator shows 300 Kts (+ or - 4 Kts).
  • Set a static pressure of 696.8 hPa (10,000 ft).

  • Set an impact pressure of 105 hPa (or total pressure of 801.8 hPa) (250 Kts).
  • Make sure that the ISIS indicator shows 10,000 ft (+ or - 50 ft).
  • Make sure that the ISIS indicator shows 250 Kts (+ or - 5 Kts).
  • Set a static pressure of 843 hPa (5000 ft).

  • Set an impact pressure of 53.5 hPa (or total pressure of 896.5 hPa) (180 Kts).
  • Make sure that the ISIS indicator shows 5000 ft (+ or - 40 ft).
  • Make sure that the ISIS indicator shows 180 Kts (+ or - 3 Kts).
  • Set a static pressure of 908.1 hPa (3000 ft).

  • Set an impact pressure of 53.5 hPa (or total pressure of 961.6 hPa) (180 Kts).
  • Make sure that the ISIS indicator shows 3000 ft (+ or - 30 ft).
  • Make sure that the ISIS indicator shows 180 Kts (+ or - 5 Kts).
  • Set a static pressure of 977.1 hPa (1000 ft).

  • Set an impact pressure of 53.5 hPa (or total pressure of 1030.6 hPa) (180 Kts).
  • Make sure that the ISIS indicator shows 1000 ft (+ or - 20 ft).
  • Make sure that the ISIS indicator shows 180 Kts (+ or - 5 Kts).
  • Slowly decrease the pressure until you get atmospheric pressure.

5. Close-up
Subtask 34-22-25-860-057-A ** ON A/C NOT FOR ALL
A. Removal of the Ground Pressure Generator
   (1) Stop the ground pressure generator.
   (2) Disconnect the ground pressure generator.
   (3) Remove the adaptors from the standby static probe and the standby pitot probe.
   (4) Remove the cover from the opposite standby static probe.
   (5) Install the slip on covers on the standby static probes and the standby pitot probe.
Subtask 34-22-25-865-057-A ** ON A/C NOT FOR ALL
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VUANTI ICE/PROBES/AOA/14DA1D04
49VUANTI ICE/PROBES/PITOT/13DA1D02
105VUELEC/CSM/G /EV AUTO/SPLY7XEC01
122VUANTI ICE/PROBES/2/PITOT3DA2Y14
122VUANTI ICE/PROBES/2/AOA4DA2Y13
122VUANTI ICE/PROBES/2/STATIC5DA2Y11
122VUANTI ICE/PROBES/3/PITOT3DA3Z16
122VUANTI ICE/PROBES/3/AOA4DA3Z15
122VUANTI ICE/PROBES/3/STATIC5DA3Z14
122VUANTI ICE/PROBES/1/STATIC5DA1Z13
Subtask 34-22-25-860-058-A ** ON A/C NOT FOR ALL
C. Put the aircraft back to its initial configuration.
   (1) Do a reset of each ELAC:
  • On the panel 49VU, open then close the ELAC1 C/B
  • On the panel 121VU, open then close the ELAC2 C/B.
   (2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
   (3) Make sure that the work area is clean and clear of tools and other items.
[Rev.10 from 2021] 2026.04.02 06:23:15 UTC
"WTRUIB" 2025