W DOC AIRBUS | AMM A320F

Functional Test of the Standby Airspeed Indicator

TASK 34-21-00-720-001-A
Functional Test of the Standby Airspeed Indicator

ZONE: 120
ZONE: 210
1. Reason for the Job
To make sure that the standby instruments operate independently.
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
3. Job Set-up
Subtask 34-21-00-860-065-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
   (1) Drain the standby air-data system (Ref. AMM TASK 12-24-34-600-001).
Subtask 34-21-00-865-056-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/TAT1DA2Y15
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
122VUANTI ICE/PROBES/1/TAT1DA1Z12
Subtask 34-21-00-865-061-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/ALTM16FNF14
Subtask 34-21-00-860-050-D ** ON A/C NOT FOR ALL
D. Aircraft Maintenance Configuration
   (1) Remove the slip on covers from the standby static probes and the standby pitot probe.
   (2) Connect the ALT34100001 PITOT AND STATIC TEST SET to the left or right standby static-probe with the ADAPTER STATIC PROBE.
   (3) Connect the ALT34100001 PITOT AND STATIC TEST SET to the standby pitot probe with the ADAPTER PITOT PROBE.
NOTE: The ADAPTER PITOT PROBE is on the drain hole. Thus it is not necessary to seal the drain hole of the pitot probe.
   (4) Seal the opposite standby static-probe with the piece of plastic and with the ADAPTER STATIC COVER from the ADAPTER STATIC PROBE.
   (5) Precautions
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).
   (6) Start the ground pressure generator.
4. Procedure
Subtask 34-21-00-720-050-A ** ON A/C NOT FOR ALL
A. Test of the Standby Airspeed Indicator
ACTION
RESULT
On the ground pressure generator :
  • Set a static pressure of 314.8 hPa (29,000 ft)
  • Set an impact pressure of 200.1 hPa (340 Kts).
On the standby airspeed indicator:
  • The pointer 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 (300 Kts).
  • The pointer shows 300 Kts (+ or - 5 Kts).
  • Set a static pressure of 843 hPa (5000 ft)
  • Set an impact pressure of 53.5 hPa (180 Kts).
  • The pointer shows 180 Kts (+ or - 5 Kts).
5. Close-up
Subtask 34-21-00-860-051-C ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
   (1) On the ground pressure generator, slowly decrease the pressure until you get atmospheric pressure.
   (2) Stop the ALT34100001 PITOT AND STATIC TEST SET.
   (3) Disconnect the ALT34100001 PITOT AND STATIC TEST SET.
   (4) Remove the adaptors from the standby static probes and the standby pitot probe.
   (5) Remove the cover from the opposite standby static probe.
   (6) Remove the piece of plastic from the opposite standby static probe.
   (7) Install the slip on covers on the standby static probes and the standby pitot probe.
   (8) 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.
Subtask 34-21-00-865-057-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/TAT1DA2Y15
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
122VUANTI ICE/PROBES/1/TAT1DA1Z12
[Rev.10 from 2021] 2026.04.02 06:23:13 UTC
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