SL No. : A319-73-002
A320-73-005
Date : 26 Sept 2022
Page : 1 of 3
SERVICE LETTER
SUBJECT:
ENG 1(2) COMPRESSOR VANE FAULT / ENGINE STALL
REFERENCES:
RYL A318/A319/A320/A321 Fleet FCTM dated 23 Nov 2021
TSM TASK 71-00-00-810-808-A Surge or Stall on Engine 1
TSM TASK 75-30-00-810-843-A Failure of the Variable Stator Vane Actuator on Engine 1, Ch A
TSM TASK 75-30-00-810-845-A Failure of the Variable Stator Vane Actuator on Engine 1, Ch B
AMM TASK 75-32-42-640-010 Inspection of the VSV Mechanism
Airbus TFU 73.00.00.090 - V2500-A5 - Transient "ENG COMP VANE" warnings
ECTM PeriodicalReport_Royal_Air_Philippines_V2500_20220902-0516
EFFECTIVITY:
All RYL-operated A319/A320 Aircraft powered with IAE V2500 Engines.
PURPOSE:
This Service Letter is issued to the Contracted Line Maintenance Provider and Flight Crew
regarding the repercussions on A/C Dispatch in order to clear such defects and close aircraft
logbook entry in relation to the above subject.
BACKGROUND:
MSN 02784 encountered inflight shutdown during approach to NNG (Flt Phase 6). First event
was with only Eng#2 operating and the second event was a successful relight of Eng#1. Both
events were reported with a Compressor Vane fault and an Engine stall.
ISSUE DESCRIPTION
An engine stall is the disruption of the airflow in a turbine engine. When the blades of the engine
compressors stall, they are no longer able to compress the air from the front to the rear of the
engine. In some cases, there may be a breakdown of the airflow, with the high-pressure air at the
end of the compressor reversing flow and exiting from the front of the engine. If this occurs, it
may result in an immediate and significant loss of thrust.
Prepared by:
Noted by:
Approved by:
Jester D. Mendoza
Date: 26 Sept 2022
John Kevin F. Dizon
Date: 26 Sept 2022
Gilbert Roland M. Reyes
Date: 26 Sept 2022
Distribution:
RYL M&E:
CONTRACTED MRO:
Email Ref: ___________________
SL No. : A319-73-002
A320-73-005
Date : 26 Sept 2022
Page : 2 of 3
SERVICE LETTER
An engine stall can be due to any of the following reasons:
- An engine degradation (e.g. compressor blade rupture, or high wear)
- Ingestion of foreign objects (e.g. birds), or ice
- A malfunction of the bleed system
- A malfunction of the engine controls (e.g. fuel scheduling, or stall protection devices)
- A significant disturbance of the airflow (e.g. due to wake turbulence, non-appropriate use of the
thrust reverser after landing, or lightning strike).
Moreover, "ENG 1(2) COMPRESSOR VANE" ECAM warnings have been reported on A320 family
aircraft fitted with V2500-A5 engines at thrust reduction from TO to CL (transition from flight phase
5 to 6), with no impact observed on main engine parameters. This warning is associated to
"CHA(B) VSV ACT/HC/EEC1(2)" failure message in the PFR, and acronym "SVATK" in FADEC
troubleshooting data. The fault can be either single or dual channel
CONSEQUENCE
These in-service events may have resulted into an Inflight Shutdown event. In order to confirm this
behavior, Maintenance and Engineering have carried out troubleshooting as per TSM tasks 75-3000-810-843/845.
However, due to the cockpit effect, these events result in troubleshooting that may end in repetitive
unnecessary LRU replacements and delays or cancellations.
INVESTIGATION AND TROUBLESHOOTING STATUS
Maintenance and Engineering has managed to complete the troubleshooting through a workorder
package for a post/follow-up check of related engine systems and components.
I. ENG1 Stall Post/Follow-Up Checks
1
BORESCOPE INSPECTION OF THE HPC STAGES 3, 6 AND 7
2
BORESCOPE INSPECTION OF THE HPC FROM STAGE 12 AND WORKING FORWARD TO
COMPLIED; NIL FINDINGS, FOUND SATISFACTORY.
STAGE 6 AND THEN STAGE 3
3
LUBRICATE AND DO A GENERAL VISUAL INSPECTION ON THE 2.5 BLEED SYS AS PER
A319
4
5
6
1
COMPLIED; NIL FINDINGS, FOUND SATISFACTORY.
COMPLIED, FOUND SATISFACTORY
COMPLIED; NIL FINDINGS, FOUND SATISFACTORY.
FUNCTIONAL CHECK OF THE PRV SOLENOID NON‐RETURN FUNCTION
COMPLIED, FOUND SATISFACTORY
CARRY OUT A PRESSURE BURNER SENSOR TEST
COMPLIED, FOUND SATISFACTORY
DVI ON THE BURNER PRESSURE SENSOR TUBE FOR WATER CONTAMINATION
II. VSV Actuator PFR Msgs identified by EEC1
REFERENCE TO REPEATED PFR MESSAGES IN THE LAST 30 FLIGHT CYCLES
COMPLIED;
OF RP-C9368, PERFORM PARA. 3.C. OF REFERENCES B AND C.
Channel A
Channel B
Channel A Channel B
[ ] SVAWAF
[ ] SVAWAF
[ ] SVAWAF [ ] SVAWAF
[X] SVAL
[X] SVAL
[X ] SVAL
[X ] SVAL
[X] SVATK
[X] SVATK
[ X] SVATK
[X ] SVATK
SERVICE LETTER
SL No. : A319-73-002
A320-73-005
Date : 26 Sept 2022
Page : 3 of 3
On the case of latest occurrence, based on all available data, the ff are applicable and probable
combined causes:
1. Significant disturbance in airflow (Weather/Turbulence)
2. Shortcomings of the EEC software and pre-mod VSV Actuator on this specific engine (Bleed
Sys + Stall Prot Devices)
Furthermore, Engine Condition Trend Monitoring (ECTM) report for the previous event, analyses
graphs show NIL spikes/indications of recurred engine performance malfunction/adverse issue
relating to Jul EGT overlimit and stall event (since 3Aug022 when we RTS 9368).
Under TFU 73.00.00.090 - V2500-A5 - Transient "ENG COMP VANE" warnings, these faults are
known issue with Airbus. NIL related AD issued. IAE had identified an area of marginality in fuel
servo pressure versus required VSV load at certain ambient conditions and engine power change
conditions.
MITIGATION / INTERIM PLAN
Although VSV actuator replacement and/or VSV system lubrication may reduce occurrence rate of
subject events, these actions are not expected to fully clear the issue. Thus, since warnings
occurring in above conditions have no impact on engine parameters, no specific maintenance is
required when this issue is experienced.
Maintenance and Engineering is also moving forward with an upgrade to new generation VSV
Actuator with a new larger piston VSV Actuator which has increased force margin. This will
generate VSV Actuator force margin in excess of the VSV system force demand, over the entire
engine operating range to help mitigate interaction messages.
In addition, to avoid stall events in descent for engines with HPC > 10,000 FC:
• When dispatching with Bleed OFF or Packs OFF as per MEL, Operational Procedure to
activate Nacelle Anti-Ice (NAI) ON in descent at 10,000 ft. is requested,
• In addition, during the flight if Bleed or Pack failure occurs or Bleed or Packs are inhibited
closed for any reason, NAI shall be selected ON in descent from 10,000 ft.,
MAINTENANCE INFORMATION
Operators experiencing such an event should refer to the appropriate TSM task which have been
updated to provide necessary steps to confirm that the event pertains to this issue and alleviate
usual maintenance requirements accordingly. It should be noted that the TSM tasks 75-30-00-810852/853 can be used accordingly.