DOC AIRBUS | TSM A320FEGT Higher than the Limit on Engine 1 (Idle and below Including Start)
1. Possible Causes
· VSV mechanism
· HP compressor
· HPT blades
· LP turbine
2 Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
REFERENCE QTY DESIGNATION
No specific 1 HOT AIR SOURCE
No specific 1 NITROGEN COMPRESSED SOURCE - GROUND
B. Referenced Information
REFERENCE DESIGNATION
75-00-00-810-804-B Hung Start/Hot Start/Stall - Effect of HPC Bleed System on Engine Operation
Ref. AMM 24-41-00-862-002 De-energize the Aircraft Electrical Circuits Supplied from the External
Power
Ref. AMM 31-60-00-860-002 EIS Stop Procedure
Ref. AMM 72-00-00-200-012 Borescope Inspection of the LP Turbine
Ref. AMM 72-00-00-200-013 Borescope Inspection of inside of Combustion Chamber and HP turbine
stage 1 Vanes
Ref. AMM 72-00-00-200-014 Borescope Inspection of the Stage 1 High Pressure Turbine (HPT)
Blades and Duct Segments
Ref. AMM 72-00-00-200-015 Borescope Inspection of the Stage 2 HPT Blades and Duct Segments
Ref. AMM 72-00-00-200-016 Inspection of the HP Compressor
Ref. AMM 72-32-60-200-011 Inspection of the LPC Bleed Duct Seal
Ref. AMM 75-32-42-200-010 Inspection of the VSV Mechanism
REFERENCE DESIGNATION
Ref. AMM 75-32-51-700-010 Functional Test of the HPC Stage 7 Solenoid Valve with Test Set
IAE2R19437
Ref. AMM 75-32-52-700-011 Functional Test of the HPC Stage 7 Bleed Valve with Test Set
IAE2R19437
Ref. AMM 75-32-53-700-010 Functional Test of the HPC Stage 10 Solenoid Valve with Test Set
IAE2R19437
Ref. AMM 75-32-54-700-011 Functional Test of the HPC Stage 10 Bleed Valve with Test Set
IAE2R19437
Ref. AMM 77-00-00-710-041 Reset of the N1, N2 and EGT Max Pointers
Ref. AMM 77-21-43-300-801 EGT Harness - Wire Braid Repair (VRS3812)
Ref. AMM 77-21-43-350-801 EGT Harness and Junction Box Dry-Out Procedure
Ref. AMM 77-21-43-700-010 Functional Test of the EGT Harness, Junction Box and Thermocouples
EGT Overtemperature Limits (Idle and below Including Start) SHEET 1
EGT Overtemperature Limits (V2530-A5, V2533-A5) (Idle and above) SHEET 1
EGT Overtemperature Limits (V2500-A1, V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5) (Idle
and above) SHEET 1
Figure 77(IAE)-00-00-991-00500-B / SHEET 1/1 - EGT Overtemperature Limits (V2530-A5, V2533-A5)
(Idle and above) not printed, as per printing preferences
Figure 77(IAE)-00-00-991-00500-A / SHEET 1/1 - EGT Overtemperature Limits (V2500-A1, V2522-A5,
V2524-A5, V2527-A5, V2527E-A5, V2527M-A5) (Idle and above) not printed, as per printing preferences
Figure 77(IAE)-00-00-991-00700-A / SHEET 1/1 - EGT Overtemperature Limits (Idle and below
Including Start) not printed, as per printing preferences
3. Fault Confirmation
Subtask 77-00-00-710-291-A
A. Test
(1) Get the EIS (DMC1) ENGINE OVER SPD/TEMP menu on the MCDU Ref. AMM 77-00-00-710-041 .
(2) On the EIS (DMC1) ENGINE OVER SPD/TEMP menu, push the line key adjacent to the Exhaust Gas
Temperature (EGT) E1 to get the EGT1 OVERTEMP menu.
(3) On the EGT1 OVERTEMP menu, get the overtemperature record. If the record is not available, see
the log book or other available records to find the time and magnitude of the overtemperature.
4. Fault Isolation
(Ref. Fig. EGT Overtemperature Limits (Idle and below Including Start) SHEET 1)
PRE SB 73-1104 for A/C 0101-0102, 0951-0951
Subtask 77-00-00-810-242-A
CAUTION: IF YOU DO NOT OBEY THE INSTRUCTIONS THAT FOLLOW, DAMAGE TO THE ENGINE
CAN BE THE RESULT.
A. Record the Following Information
NOTE: If the cause of the overtemperature is determined during this procedure, it is permitted to stop the
troubleshooting.
NOTE: If troubleshooting for surge or stall has required a borescope inspection, the steps to borescope
the previously inspected components may be skipped.
(1) Engine serial number
NOTE: If engine serial number displayed on MCDU is in the range between 13191 and 15000, then
add 5000 to this value to get the actual engine serial number.
(2) Maximum temperature
(3) Time of overtemperature above 635 deg.C (1175 deg.F).
NOTE: If the fault symptom ENG1-EGT more than 610 deg.C (1130 deg.F) was identified by crew observation,
you must also record the time during which the engine was above 610 deg.C (1130
deg.F).
** ON A/C
POST SB 73-1104 for A/C 0101-0102, 0951-0951
Subtask 77-00-00-810-242-B
CAUTION: IF YOU DO NOT OBEY THE INSTRUCTIONS THAT FOLLOW, DAMAGE TO THE ENGINE
CAN BE THE RESULT.
A. Record the Following Information
NOTE: If the cause of the overtemperature is determined during this procedure, it is permitted to stop the
troubleshooting.
NOTE: If troubleshooting for surge or stall has required a borescope inspection, the steps to borescope
the previously inspected components may be skipped.
(1) Engine serial number
(2) Maximum temperature
(3) Time of overtemperature above 635 deg.C (1175 deg.F).
NOTE: If the fault symptom ENG1-EGT more than 610 deg.C (1130 deg.F) was identified by crew observation,
you must also record the time during which the engine was above 610 deg.C (1130
deg.F).
Subtask 77-00-00-810-243-A
B. Find out if the cause the EGT overtemperature was an indication system error. If the condition that follows
is met, continue with step C, otherwise continue with step D.
(1) There is an EGT overtemperature when fuel consumption is zero.
(2) EGT fluctuates with no related change in N1 or fuel consumption.
NOTE: A general trend of declining EGT margin associated with a rise in fuel consumption could be a
sign of deteriorating High Pressure Turbine (HPT) stage 1 outer air seals.
Subtask 77-00-00-810-244-A
C. Do the steps that follow if any of the conditions in step B occurred.
(1) Do a visual inspection of the EGT harness, junction box and thermocouples.
(a) If the EGT harness is chafed, repair as per Ref. AMM 77-21-43-300-801 .
(b) If there is moisture accumulation in the junction box, use HOT AIR SOURCE or NITROGEN
COMPRESSED SOURCE - GROUND to remove the moisture Ref. AMM 77-21-43-350-801 .
(c) If there are broken stud short circuits because of misplaced safety wires or physical damage
other than harness chafing, remove, replace, or correct the applicable hardware.
(2) If you do not find a problem, do electrical checks of the EGT system Ref. AMM 77-21-43-700-010 .
(3) If you find a problem with the EGT hardware, replace the applicable hardware and return the engine
to service.
(4) If the EGT hardware is serviceable, continue to step D.
Subtask 77-00-00-810-245-A
D. Refer to Overtemperature Limits for Necessary Action
(Ref. Fig. EGT Overtemperature Limits (Idle and below Including Start) SHEET 1)
(1) If overtemperature was in area A or B with one or more events, or if overtemperature was in area B
with less than six EGT overtemperature events, perform the troubleshooting in step E.
(2) If overtemperature was in area B with six or more EGT overtemperature events or if overtemperature
was in area C with one or more EGT overtemperature events, perform the troubleshooting in step F.
(3) If overtemperature was in area D with any number of events, perform the troubleshooting in step G.
Subtask 77-00-00-810-246-B
E. Do the steps that follow to find the cause of EGT that is too high.
(1) Examine the TEC for debris.
(a) If debris is found, remove the engine from service.
(2) Inspect the VSV mechanism Ref. AMM 75-32-42-200-010 .
(3) Do the functional check of the bleed valve and solenoid operation on engine 1 Ref.
AMM 75-32-51-700-010 Ref. AMM 75-32-52-700-011 Ref. AMM 75-32-53-700-010 and Ref.
AMM 75-32-54-700-011 .
NOTE: Refer to (Ref. TSM 75-00-00-810-804) for more information on the bleed valve effects on engine
operation.
(4) Do a functional test of the HP compressor bleed valve system.
(5) Do an inspection of the LP compressor bleed duct for a detached seal Ref. AMM 72-32-60-200-011 .
(6) Examine for broken turbine cooling air supply tubes.
(Ref. Fig. EGT Overtemperature Limits (V2530-A5, V2533-A5) (Idle and above) SHEET 1)
Figure 77(IAE)-00-00-991-00500-B / SHEET 1/1 - EGT Overtemperature Limits
(V2530-A5, V2533-A5) (Idle and above) not printed, as per printing preferences
(Ref. Fig. EGT Overtemperature Limits (V2500-A1, V2522-A5, V2524-A5, V2527-A5, V2527E-A5,
V2527M-A5) (Idle and above) SHEET 1)
Figure 77(IAE)-00-00-991-00500-A / SHEET 1/1 - EGT Overtemperature Limits
(V2500-A1, V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5) (Idle and
above) not printed, as per printing preferences
(7) If you do not know the cause of EGT that is too high, do the steps that follow:
(a) Borescope inspect the HP compressor Ref. AMM 72-00-00-200-016 .
(b) Borescope inspect the combustion chamber Ref. AMM 72-00-00-200-013 .
(c) Borescope inspect the HPT blades .
1 Borescope inspect the stage 1 HPT blades Ref. AMM 72-00-00-200-014 .
2 Borescope inspect the stage 2 HPT blades Ref. AMM 72-00-00-200-015 .
(d) Borescope inspect the LP turbine Ref. AMM 72-00-00-200-012 .
(8) Examine the EGT margin as follows:
PRE SBE 72-0483
(a) Do a 360 degree borescope inspection of the stage 1 HPT duct segments Ref.
AMM 72-00-00-200-014 if one or more of the conditions that follow are true:
1 EGT margin is less than 45 deg.C (113 deg.F) and the engine has accumulated more than
6000 hours or more than 3500 cycles.
2 EGT margin is less than 10 deg.C (50 deg.F).
3 EGT margin is not available.
END OF PRE SBE 72-0483
POST SBE 72-0483
(b) Do a 360 degree borescope inspection of the stage 1 HPT duct segments Ref.
AMM 72-00-00-200-014 if one or more of the conditions that follow are true:
1 EGT margin is less than 10 deg.C (50 deg.F).
2 EGT margin is not available.
NOTE: If a 360 degree borescope inspection of the stage 1 HPT duct segments has been
done within 300 hours and the engine is not on a reduced BSI interval for stage 1
HPT duct segment distress, then this borescope inspection is not necessary.
END OF POST SBE 72-0483
(9) If you do not know the cause of EGT that is too high, do a functional test of the EGT harness and
junction box Ref. AMM 77-21-43-700-010 .
Subtask 77-00-00-810-247-A
F. Do the steps that follow to find the cause of EGT overtemperature if the overtemperature was in area B
with six or more EGT overtemperature events or if overtemperature was in area C with one or more EGT
overtemperature events.
NOTE: You can ferry-fly a non revenue engine with overtemperature to a maintenance base, but a visual
inspection and a hot section borescope inspection Ref. AMM 72-00-00-200-013 thru Ref.
AMM 72-00-00-200-015 must show no visual damage. This condition is permitted for only one engine
per aircraft.
(1) Remove the engine from service and complete the following tasks:
(a) Complete the hot section borescope inspection.
(b) Metallurgical analysis of the stage 1 and 2 HPT blades.
NOTE: If the stage 2 HPT blades are rejected for overtemperature, the stage 3 Low Pressure
Turbine (LPT) blades must have a metallurgical analysis.
Subtask 77-00-00-810-248-A
G. Do the steps that follow to find the cause of EGT overtemperature if the overtemperature was in area D
with any number of EGT overtemperature events.
(1) No action is necessary. Return the engine to service.
5. Close-up
Subtask 77-00-00-860-110-A
A. Put the aircraft back to its initial configuration.
(1) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
Ref. AMM 31-60-00-860-002 .
(2) De-energize the aircraft electrical circuits
Ref. AMM 24-41-00-862-002 . [Rev.6 from Feb 2017] 2026.04.04 04:37:50 UTC