W DOC AIRBUS | TSM A320F

Failure of the Control of the Variable Bleed Valve (VBV) Actuator on Engine 2 - Channel B

TASK 75-30-00-810-838-A
Failure of the Control of the Variable Bleed Valve (VBV) Actuator on Engine 2 - Channel B

1. Possible Causes
  • flexible shaft
  • VBV ballscrew actuator
  • VBV gear motor
  • VBV stop mechanism assembly
  • main flexible shaft
  • VBV master ballscrew actuator
  • VBV sensor (RVDT)
  • ECU [4000KS]
  • VBV stop mechanism
  • VBV master door actuator
  • HMU-2 [4000KC2]
  • harness J8
  • flexible shafts
  • harness HJ8
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
79001209-1
2
HONEYWELL TOOLING
 B. Referenced Information
REFERENCE
DESIGNATION
AMM 73-21-10-000-001
Removal of the Hydromechanical Unit (HMU)
AMM 73-21-10-000-002
Removal of the Hydromechanical Unit (HMU)
AMM 73-21-10-400-001
Installation of the Hydromechanical Unit (HMU)
AMM 73-21-10-400-002
Installation of the Hydromechanical Unit (HMU)
AMM 73-21-50-000-007
Removal of J8 Harness
AMM 73-21-50-000-041
Removal of the HJ8 Harness for SAC Engines
AMM 73-21-50-210-001
Visual Inspection of the Wiring Harness
AMM 73-21-50-210-002
Visual Inspection of the Wiring Harnesses
AMM 73-21-50-400-007
Installation of the J8 Harness
AMM 73-21-50-400-041
Installation of the HJ8 Harness for SAC Engines
AMM 73-21-60-000-001
Removal of the Electronic Control Unit (ECU)
AMM 73-21-60-400-001
Installation of the Electronic Control Unit (ECU)
AMM 73-29-00-710-040
Operational Test of the FADEC on the ground (with Engine Motoring)
AMM 75-31-00-200-001
Manual Operation Check of the Variable Bleed Valve Doors
AMM 75-31-00-200-002
Manual Operation Check of the Variable Bleed Valve Doors
AMM 75-31-00-640-801
Re-greasing of the Variable Bleed Valve (VBV) System
AMM 75-31-10-000-001
Removal of the Bleed Valve Fuel Gear Motor Assembly
AMM 75-31-10-000-002
Removal of the Bleed Valve Fuel Gear Motor Assembly
AMM 75-31-10-400-001
Installation of the Bleed Valve Fuel Gear Motor Assembly
AMM 75-31-10-400-002
Installation of the Bleed Valve Fuel Gear Motor Assembly
AMM 75-31-20-000-001
Removal of the Bleed Valve Stop Mechanism
AMM 75-31-20-000-002
Removal of the Bleed Valve Stop Mechanism
AMM 75-31-20-400-001
Installation of the Bleed Valve Stop Mechanism
AMM 75-31-20-400-002
Installation of the Bleed Valve Stop Mechanism
AMM 75-31-30-000-001
Removal of a VBV Inter-connecting Flexible Shaft (Typical).
AMM 75-31-30-000-002
Removal of the VBV System Main Flexible Shaft
AMM 75-31-30-000-003
Removal of a VBV Inter-connecting Flexible Shaft (Typical)
AMM 75-31-30-000-004
Removal of the VBV System Main Flexible Shaft
AMM 75-31-30-200-001
Visual Inspection of the VBV Main Flexible Shaft and the VBV Inter-connecting Flexible Shafts
AMM 75-31-30-200-002
Visual Inspection of the VBV Main Flexible Shaft and the VBV Inter-connecting Flexible Shafts
AMM 75-31-30-400-001
Installation of a VBV Inter-connecting Flexible Shaft (Typical)
AMM 75-31-30-400-002
Installation of the VBV System Main Flexible Shaft
AMM 75-31-30-400-003
Installation of a VBV Inter-connecting Flexible Shaft (Typical)
AMM 75-31-30-400-004
Installation of the VBV System Main Flexible Shaft
AMM 75-31-50-000-001
Removal of the Bleed Valve and Master Ballscrew Actuator
AMM 75-31-50-000-002
Removal of the Bleed Valve and Master Ballscrew Actuator Assembly
AMM 75-31-50-400-001
Installation of the Bleed Valve and Master Ballscrew Actuator
AMM 75-31-50-400-002
Installation of the Bleed Valve and Master Ballscrew Actuator Assembly
AMM 75-31-60-000-001
Removal of the Bleed Valve and Ballscrew Actuator Assembly
AMM 75-31-60-000-002
Removal of the Bleed Valve and Ballscrew Actuator Assembly
AMM 75-31-60-400-001
Installation of the Bleed Valve and Ballscrew Actuator Assembly
AMM 75-31-60-400-002
Installation of the Bleed Valve and Ballscrew Actuator Assembly
AMM 75-31-70-000-001
Removal of the Variable Bleed Valve Position Sensor
AMM 75-31-70-000-002
Removal of the Variable Bleed Valve position Sensor
AMM 75-31-70-400-001
Installation of the Variable Bleed Valve Position Sensor
AMM 75-31-70-400-002
Installation of the Variable Bleed Valve position Sensor
F VBV Actuator and Doors
F Honeywell Back Driving Test Tool
3. Fault Confirmation
Subtask 75-30-00-710-144-A ** ON A/C NOT FOR ALL
A. Do the operational test of FADEC 2B on the ground (with engine motoring) AMM 73-29-00-710-040.
NOTE: The failure message is generated if the actual position and the demanded position of the VBV system disagree (only the position of VBV master actuator door is monitored).
NOTE: There is no expected position of the VBV actuators on a non-running engine. The position of the VBV actuators must be uniform but can be either open, closed or intermediate.
4. Fault Isolation
Subtask 75-30-00-810-099-A ** ON A/C NOT FOR ALL
A. If the FADEC test does not give the maintenance message "VBV ACT, HMU":
  • Do a visual inspection of all the VBV door actuators and flexible shafts, check for an offset of position between all the VBV doors with fan frame (all the VBV doors not set in the same position):
   (1) If an offset between the VBV doors or finding on to the VBV flexible shafts is observed:
     (a) Remove all the flexible shafts AMM 75-31-30-000-003.
     (b) Inspect each flexible shaft AMM 75-31-30-200-001. If not serviceable, replace any flexible shaft AMM 75-31-30-000-003 and AMM 75-31-30-400-003.
     (c) Manually operate each of the 11 VBV actuators in both directions and make sure that each actuator moves smoothly and freely.
  • During this check, slightly open the VBV doors with the hexagonal end, then take the VBV plate door by hand and open and close the VBV door by applying a manual force on the door,
  • If any binding or sticking point is noted or if any VBV door is found hard to rotate, do a backdriving test using 79001209-1 HONEYWELL TOOLING or equivalent to check that the force necessary to open the VBV door is not more than 60 lbf (26.69 daN),
  • If the force to open the VBV door is more than 60 lbf (26.69 daN), replace the VBV ballscrew actuator AMM 75-31-60-000-001 and AMM 75-31-60-400-001.
   (2) If nothing is found, the following Trouble Shooting must be performed at the first opportunity within 10 cycles (except if the fault re-occurs):
     (a) Do a check of the rigging of the feedback rod to the VBV position sensor (RVDT) AMM 75-31-70-400-001.
     (b) Remove the VBV gear motor/stop mechanism assembly AMM 75-31-10-000-001.
     (c) Manually check for free rotation of the VBV gear motor. If it does not move freely, replace the VBV gear motor AMM 75-31-10-000-001 and AMM 75-31-10-400-001.
     (d) Manually check for free rotation of the stop mechanism. Using the main flexible shaft, check for full travel of the nut follower by turning the main flexible shaft counterclockwise and clockwise until the follower nut is against the mechanical stop. If it does not move freely, replace the VBV stop mechanism assembly AMM 75-31-20-000-001 and AMM 75-31-20-400-001.
     (e) Inspect the main flexible shaft AMM 75-31-30-200-001. If not serviceable, replace the main flexible shaft AMM 75-31-30-000-004 and AMM 75-31-30-400-004.
     (f) Remove all the flexible shafts AMM 75-31-30-000-003.
     (g) Inspect each flexible shaft AMM 75-31-30-200-001. If not serviceable, replace any flexible shaft AMM 75-31-30-000-003 and AMM 75-31-30-400-003. If the flexible shaft are not serviceable, all the VBV doors must be inspected and manually operated.
     (h) Manually operate each of the 11 VBV actuators in both directions and make sure that each actuator moves smoothly and freely.
  • During this check, slightly open the VBV doors with the hexagonal end, then take the VBV plate door by hand and open and close the VBV door by applying a manual force on the door,
  • If any binding or sticking point is noted or if any VBV door is found hard to rotate, do a backdriving test using 79001209-1 HONEYWELL TOOLING or equivalent and pull scale to check that the force necessary to open the VBV door is not more than 60 lbf (26.69 daN),
  • If the force to open the VBV door is more than 60 lbf (26.69 daN), replace the VBV ballscrew actuator AMM 75-31-60-000-001 and AMM 75-31-60-400-001.
     (i) Manually operate the VBV master door actuator in both directions and make sure that it moves smoothly and freely.
  • During this check, slightly open the VBV master door with the hexagonal end, then take the VBV plate door by hand and open and close the VBV master door by applying a manual force on the door,
  • If any binding or sticking is noted or if the VBV master door is found hard to rotate, do a backdriving test using 79001209-1 HONEYWELL TOOLING or equivalent and pull scale to check that the force necessary to open the VBV master door is not more than 90 lbf (40.03 daN),
  • If the force to open the VBV master door is more than 90 lbf (40.03 daN), replace the VBV master ballscrew actuator AMM 75-31-50-000-001 and AMM 75-31-50-400-001.
     (j) If no fault is found:
  • Disconnect the harness J8 from the ECU receptacle and visually examine the receptacle and the connector for pins in poor condition or contamination AMM 73-21-50-210-001.
  • Disconnect the harness J8 connector from the HMU receptacle and visually examine the receptacle and the connector for pins in poor condition or contamination AMM 73-21-50-210-001.
       1 If no fault is found:
. Do a check of the Post Flight Report (PFR) and the Schedule Maintenance Report (SMR)/Class 3 report for the maintenance message(s) VBV SNSR, J11, ECU and/or VBV SNSR, J12, ECU
. Replace the VBV sensor (RVDT) AMM 75-31-70-000-001 and AMM 75-31-70-400-001.
       2 If the fault continues during the subsequent flight:
Subtask 75-30-00-810-111-A ** ON A/C NOT FOR ALL
B. If the test gives the maintenance message VBV ACT, HMU:
   (1) Do a visual inspection of all the VBV door actuators and flexible shafts through the fan duct panels, check for an offset of position between all the VBV doors (all the VBV doors not set in the same positon):
  • If an offset between VBV doors or finding to VBV flexible shafts is observed, do an inspection of the VBV doors, go to the Para. 4.A.(1).
   (2) Manually operate the VBV system manually and make sure that it moves smoothly and freely AMM 75-31-00-200-001.
     (a) If the system is hard to rotate or does not move freely (non-constant torque) or is an offset of position is observed between the VBV doors:
  • Operate each of the 11 VBV actuators in both directions and make sure that each moves smoothly and freely.
NOTE: During this check, apply a manual load tending to force the door towards its open position. Replace any suspect VBV ballscrew actuator AMM 75-31-60-000-001 and AMM 75-31-60-400-001.
       1 Remove the VBV gear motor/stop mechanism assembly AMM 75-31-10-000-001.
         a Check for free rotation of the VBV gear motor. If it does not move freely, replace the VBV gear motor AMM 75-31-10-000-001 and AMM 75-31-10-400-001.
         b Check for free rotation of the stop mechanism. Using the main flexible shaft, check for full travel of the nut follower by turning the main flexible shaft counterclockwise and clockwise until the follower nut is against the mechanical stop. If it does not move freely, replace the VBV stop mechanism AMM 75-31-20-000-001 and AMM 75-31-20-400-001.
         c Check for free rotation of the VBV master door actuator. If it does not move freely, replace the VBV master door actuator AMM 75-31-50-000-001 and AMM 75-31-50-400-001.
       2 Inspect the main flexible shaft AMM 75-31-30-200-001. If not serviceable, replace the main flexible shaft in case of excessive wear AMM 75-31-30-000-004 and AMM 75-31-30-400-004.
       3 Remove all the flexible shafts AMM 75-31-30-000-003.
         a Inspect each flexible shaft AMM 75-31-30-200-001. If not serviceable, replace any flexible shaft AMM 75-31-30-000-003 and AMM 75-31-30-400-003. In case of wear on the flexible shaft, all the VBV doors must be inspected and manually operated.
         b Manually operate each of the 11 VBV actuators in both directions and make sure that each moves smoothly and freely.
  • During this check, slightly open the VBV master door with the hexagonal end, then take the VBV plate door by hand and open and close the VBV master door by applying a manual force on the door,
  • If any binding or sticking is noted or if the VBV master door is found hard to rotate, do a backdriving test using 79001209-1 HONEYWELL TOOLING or equivalent and pull scale to check that the force necessary to open the VBV master door is not more than 90 lbf (40.03 daN),
  • If the force to open the VBV master door is more than 90 lbf (40.03 daN), replace the VBV master ballscrew actuator AMM 75-31-50-000-001 and AMM 75-31-50-400-001.
       4 Manually operate the VBV master door actuator in both directions and make sure that it moves smoothly and freely.
  • During this check, slightly open the VBV master door with the hexagonal end, then take the VBV plate door by hand and open and close the VBV master door by applying a manual force on the door,
  • If any binding or sticking is noted or if the VBV master door is found hard to rotate, do a backdriving test using 79001209-1 HONEYWELL TOOLING or equivalent and pull scale to check that the force necessary to open the VBV master door is not more than 90 lbf (40.03 daN),
  • If the force to open the VBV master door is more than 90 lbf (40.03 daN), replace the VBV master ballscrew actuator AMM 75-31-50-000-001 and AMM 75-31-50-400-001.
     (b) If the system is not hard to rotate and moves freely and smoothly:
  • Disconnect harness J8 from the ECU receptacle:
       1 Visually examine the receptacle and connector for pins in poor condition or contamination AMM 73-21-50-210-001
       2 Do an electrical resistance check through the J8 harness between:
. Pins 29 and 30 (17 to 23 Ohms).
         a If the resistance value is in the specified limits:
         b If the resistance value is out of the specified limits:
Subtask 75-30-00-810-099-B ** ON A/C NOT FOR ALL
C. If the test does not give the maintenance message "VBV ACT, HMU":
  • Do a visual inspection of all VBV door actuators and flexible shafts, check for an offset of position between all the VBV doors with the fan frame (all the VBV doors not set in the same position).
   (1) If an offset between the VBV doors or finding on the VBV flexible shafts is observed:
     (a) Remove all the flexible shafts AMM 75-31-30-000-001.
     (b) Inspect each flexible shaft AMM 75-31-30-200-002. If not serviceable, replace any flexible shaft AMM 75-31-30-000-001 and AMM 75-31-30-400-001.
     (c) Manually operate each of the 11 VBV actuators in both directions and make sure that each VBV actuator moves smoothly and freely.
  • During this check, slightly open the VBV doors with the hexagonal end, then take the VBV plate door and open and close the VBV door by applying a manual force on the door.
  • If any binding or sticking point is found or if any VBV door is found hard to rotate, do a back driving test using the 79001209-1 HONEYWELL TOOLING or equivalent to check that the force necessary to open the VBV door is not more than 60 lbf (26.69 daN).
  • If the force to open the VBV door is not more than 60 lbf (26.69 daN), do a re-greasing of the VBV system AMM 75-31-00-640-801.
  • If the force to open the VBV door is more than 60 lbf (26.69 daN), replace the VBV ballscrew actuator AMM 75-31-60-000-002 and AMM 75-31-60-400-002.
   (2) If nothing is found, the following Trouble Shooting must be performed at the first opportunity within 10 cycles (except if the fault re-occurs):
     (a) Do a check of the rigging of the feedback rod to the VBV position sensor (RVDT) AMM 75-31-70-400-002.
     (b) Remove the VBV gear motor/stop mechanism assembly AMM 75-31-20-000-002.
     (c) Manually check for free rotation of the VBV gear motor. If it does not move freely, replace the VBV gear motor AMM 75-31-10-000-002 and AMM 75-31-10-400-002.
     (d) Manually check for free rotation of the stop mechanism. Using the main flexible shaft, check for full travel of the nut follower by turning the main flexible shaft counterclockwise and clockwise until the follower nut is against the mechanical stop. If it does not move freely, replace the VBV stop mechanism AMM 75-31-20-000-002 and AMM 75-31-20-400-002.
     (e) Inspect the main flexible shaft AMM 75-31-30-200-002.
     (f) Remove all the flexible shafts AMM 75-31-30-000-001.
     (g) Inspect each flexible shaft AMM 75-31-30-200-002. If not serviceable replace flexible shaft AMM 75-31-30-000-001 and AMM 75-31-30-400-001 as necessary. If the flexible shafts are not serviceable, all the VBV doors must be inspected and manually operated.
     (h) Manually operate each of the 11 VBV actuators in both directions and make sure that each VBV actuator moves smoothly and freely.
  • During this check, slightly open the VBV doors with the hexagonal end, then take the VBV plate door and open and close the VBV door by applying a manual force on the door.
  • If any binding or sticking point is found or if any VBV door is found hard to rotate, do a back driving test using the 79001209-1 HONEYWELL TOOLING or equivalent and pull the scale to check that the force necessary to open the VBV door is not more than 60 lbf (26.69 daN).
  • If the force to open the VBV door is not more than 60 lbf (26.69 daN), do a re-greasing of the VBV system AMM 75-31-00-640-801.
  • If the force to open the VBV door is more than 60 lbf (26.69 daN), replace the VBV ballscrew actuator AMM 75-31-60-000-002 and AMM 75-31-60-400-002.
     (i) Manually operate the VBV master door actuator in both directions and make sure that it moves smoothly and freely.
  • During this check, slightly open the VBV master door with the hexagonal end, then take the VBV plate door by hand and open and close the VBV master door by applying a manual force on the door.
  • If any binding or sticking is found or if the VBV master door is found hard to rotate, do a back driving test using the 79001209-1 HONEYWELL TOOLING or equivalent and pull the scale to check that the force necessary to open the VBV master door is not more than 90 lbf (40.03 daN).
  • If the force to open the VBV master door is not more than 90 lbf (40.03 daN), do a re-greasing of the VBV System AMM 75-31-00-640-801.
  • If the force to open the VBV master door is more than 90 lbf (40.03 daN), replace the VBV ballscrew actuator AMM 75-31-50-000-002 and AMM 75-31-50-400-002.
     (j) If no fault is found:
  • Disconnect harness HJ8 from the ECU receptacle and visually examine the receptacle and the connector for pins in poor condition or contamination AMM 73-21-50-210-002.
  • Disconnect harness HJ8 from the HMU receptacle and visually examine the receptacle and the connector for pins in poor condition or contamination AMM 73-21-50-210-002.
       1 If no fault is found:
       2 If the fault continues:
  • Do a check of the Post Flight Report (PFR) and the Schedule Maintenance Report (SMR)/Class 3 report for the maintenance message(s) VBV SNSR, J11, ECU and/or VBV SNSR, J12, ECU.
  • Replace the VBV sensor (RVDT) AMM 75-31-70-000-002 and AMM 75-31-70-400-002.
     (k) If the fault continues during the subsequent flight:
Subtask 75-30-00-810-111-B ** ON A/C NOT FOR ALL
D. If the test gives the maintenance message VBV ACT, HMU:
   (1) Do a visual inspection of all the VBV door actuators and flexible shafts through the fan duct panels, check for an offset of position between all the VBV doors (all the VBV doors not set in the same positon).
  • If an offset between VBV doors or finding to VBV flexible shafts is observed, do an inspection of the VBV doors, Refer to Para. 4.A.(1).
   (2) Manually operate the VBV system manually and make sure that it moves smoothly and freely AMM 75-31-00-200-002.
     (a) If the system is hard to rotate or does not move freely (the torque is not constant) or if an offset of position is observed between the VBV doors:
       1 Remove the VBV gear motor/stop mechanism assembly AMM 75-31-10-000-002.
         a Check for free rotation of the VBV gear motor. If it does not move freely, replace the VBV gear motor AMM 75-31-10-000-002 and AMM 75-31-10-400-002.
         b Check for free rotation of the stop mechanism. Using the main flexible shaft, check for full travel of the nut follower by turning the main flexible shaft counterclockwise and clockwise until the follower nut is against the mechanical stop. If it does not move freely, replace the VBV stop mechanism AMM 75-31-20-000-002 and AMM 75-31-20-400-002.
       2 Inspect the main flexible shaft AMM 75-31-30-200-002. If not serviceable, replace the main flexible shaft AMM 75-31-30-000-002 and AMM 75-31-30-400-002.
       3 Remove all the flexible shafts AMM 75-31-30-000-001.
         a Inspect each flexible shaft AMM 75-31-30-200-002. If not serviceable, replace the flexible shafts AMM 75-31-30-000-001 and AMM 75-31-30-400-001 as necessary. In case of finding on the flexible shafts, all the VBV doors must be inspected and manually operated.
         b Manually operate each of the 11 VBV actuators in both directions and make sure that each VBV actuator moves smoothly and freely.
  • During this check, slightly open the VBV doors with the hexagonal end, then take the VBV plate door by hand and open and close the VBV door by applying a manual force on the door.
  • If any binding or sticking point is found or if any VBV door is found hard to rotate, do a back driving test using the 79001209-1 HONEYWELL TOOLING or equivalent and pull the scale to check that the force necessary to open the VBV door is not more than 60 lbf (26.69 daN).
  • If the force to open the VBV door is more than 60 lbf (26.69 daN), replace the VBV ballscrew actuator AMM 75-31-60-000-002 and AMM 75-31-60-400-002.
  • If any binding or sticking is found, or if any VBV door is found hard to rotate, do a re-greasing of the VBV system AMM 75-31-00-640-801.
       4 Manually operate the VBV master door actuator in both directions and make sure that it moves smoothly and freely.
  • During this check, slightly open the VBV master door with the hexagonal end, then take the VBV plate door by hand and open and close the VBV master door by applying a manual force on the door.
  • If any binding or sticking is found or if the VBV master door is found hard to rotate, do a back driving test using the 79001209-1 HONEYWELL TOOLING or equivalent and the pull scale to check that the force necessary to open the VBV master door is not more than 90 lbf (40.03 daN).
  • If the force to open the VBV master door is more than 90 lbf (40.03 daN), replace the VBV ballscrew actuator AMM 75-31-50-000-002 and AMM 75-31-50-400-002.
  • If any binding or sticking is found, or if the VBV master door is found hard to rotate, do a re-greasing of the VBV system AMM 75-31-00-640-801.
     (b) If the system is not hard to rotate and moves freely and smoothly:
  • Disconnect harness HJ8 from the ECU receptacle:
       1 Visually examine the receptacle and connector for pins in poor condition or contamination AMM 73-21-50-210-002.
       2 Do an electrical resistance check through the HJ8 harness between:
. Pins 29 and 30 (17 to 23 Ohms).
         a If the resistance value is in the specified limits:
         b If the resistance value is out of the specified limits:
Subtask 75-30-00-710-145-A ** ON A/C NOT FOR ALL
E. Do the test given in Para. 3.A.
   (1) If the fault is not confirmed:
  • No additional maintenance action is necessary.
   (2) If the fault continues:
  • Do the fault isolation procedure again.
[Rev.8 from Aug 2018] 2026.04.04 04:37:10 UTC
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