W DOC AIRBUS | AMM A320F

Abnormal Operation and Emergency Procedures [CFMI]


TASK 71-00-00-869-001-A
Abnormal Operation and Emergency Procedures


CAUTION: DO NOT PERMIT THE ENGINE TO BE OPERATED AT A TEMPERATURE ABOVE THE EGT LIMIT. ALSO DO NOT OPERATE THE ENGINE AGAIN AND AGAIN AT HIGH EGT LEVELS. DOING SO WILL CAUSE THE ENGINE TO DETERIORATE BEFORE THE USUAL TIME. WRITE HOT STARTS AND OVERTEMPERATURE CONDITIONS IN THE AIRCRAFT LOG.
1. Reason for the Job
These procedures show conditions that can be found during engine operation and the emergency action that must be taken to stop the abnormal condition. To correct the cause of the abnormal condition refer to Trouble Shooting Manual.
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TASK 29-10-00-710-001-A
Operational Check of Hydraulic Fire Shut Off Valves and Associated Indicating System
TASK 71-00-00-710-001-A
Dry Motoring Check
TASK 71-00-00-710-002-A
Wet Motoring Check
TASK 71-00-00-710-003-A
Engine Automatic Start
TASK 72-00-00-200-002-A
Procedure After Engine Fire or Use of Fire-Extinguishing Agents
TASK 72-00-00-200-003-A
Procedure After the Engine has Exceeded the Operational Limits
3. Job Set-up
Subtask 71-00-00-869-086-A ** ON A/C NOT FOR ALL
A. Not Applicable
4. Procedure
Subtask 71-00-00-869-075-A ** ON A/C NOT FOR ALL
A. Do these procedures as necessary
   (1) Hot Start during the Manual Start Procedure
     (a) A possible hot start can be identified by an unusually fast EGT increase after engine light-off. The EGT will most likely go higher than the limits if the start is not aborted in time. A hot start can be anticipated and aborted before the 725 deg.C (1337 deg.F) limit is gone beyond.
     (b) Hot starts can be caused by the conditions which follow:
       1 A compressor stall.
       2 A low starter air pressure. This can cause the N2 to be less than the amount needed to provide sufficient compressor air flow.
       3 A faulty starter valve. This can prevent correct starter operation.
       4 The starter is stopped too soon.
       5 The incomplete purging of the fuel remaining in the combustion chamber after an earlier start try.
       6 Foreign Object Damage (FOD). This can prevent sufficient engine acceleration and airflow.
       7 A faulty pressurizing valve (hung open). This can cause fuel to puddle in the combustion chamber before light-off.
       8 Incorrect scheduling of the variable stator vanes (VSV).
     (c) Hot start procedure
       1 If the EGT goes near the limits, use the procedure that follows:
         a On the ENG panel 115VU:
  • Set the ENG/MASTER 1(2) switch to OFF.
  • Set the ENG/MODE/CRANK/NORM/IGN/START selector switch to CRANK (dry motor the engine for 30 seconds) (Ref. AMM TASK 71-00-00-710-001).
         b On the overhead CTL & IND panel 22VU:
  • Release the ENG/MAN START/1(2) pushbutton switch (the ON legend of this pushbutton switch goes off).
         c On the ENG panel 115VU:
  • Set the ENG/MODE/CRANK/NORM/IGN/START selector switch to NORM.
       2 If the fuel flow during the first start try before light-off was more than 460 pph (209 kg/h), or the maximum motoring speed you were able to reach was less than 20 percent N2, do this before a restart try:
  • If the fuel flow was high, do a wet motoring to make sure the flow value was correct (Ref. AMM TASK 71-00-00-710-002).
  • If the motoring speed was low, make sure the starter air pressure is correct. Also make sure that the starter valve operates normally, and the engine core turns freely.
   (2) Hung Start during Manual Start Procedure
     (a) Hung start
       1 A hung start can be identified by a light-off followed by an unusually slow acceleration and an rpm that stabilizes at less than idle.
       2 A hung start can also be caused by fuel scheduling that is too lean or too rich. A lean hung start can be identified by a low fuel flow and EGT in low proportion to the fuel flow.
       3 A rich hung start can be identified by high fuel flow and an EGT increase that may turn into an overtemperature condition, and is most likely caused by a compressor stall.
     (b) Hung start causes
       1 The starter air pressure is too low to accelerate the engine to a self-sustaining speed.
       2 FOD to the compressor.
       3 A faulty starter valve.
       4 A faulty pressurizing valve that is not opening at the scheduled fuel pressure setting.
       5 Incorrect scheduling of the HP compressor IGV and the variable stators.
       6 Turbine section damage.
     (c) Hung start procedure
       1 A hung start can possibly be corrected by doing one of the steps that follow:
         a For lean hung starts, increase the starter air pressure or windmill N2 speed.
         b If a hung start cannot be corrected by the recommended procedure, use the Auto Start procedure as there is automatic cross channel/fault selection (Ref. AMM TASK 71-00-00-710-003).
       2 Write the values that follow in the aircraft log: The starter air pressure.
         a The starting fuel flow.
         b The maximum N2 speed.
         c The maximum EGT.
NOTE: If the fuel flow indication before the light-off was less than 300 pph (136 kg/h), or if the maximum motoring speed was less than 20 percent N2, a corrective action will probably be needed.
   (3) Overtemperature during Manual Start Procedure
     (a) Do not permit the EGT to go higher than the 725 deg.C (1337 deg.F) limit during starting . All temperatures that are more than this are overtemperatures .
     (b) Write the length of time an overtemperature lasts, and temperature reached in the Aircraft Log. See (Ref. AMM TASK 72-00-00-200-003) for unscheduled inspection after engine overtemperature.
     (c) Do a General Visual Inspection of the surrounding aircraft structure (pylon, wing lower skin, flap, flap track fairing) for signs of damage.
   (4) Unsatisfactory Starts during the Automatic Start Procedure
     (a) The unsatisfactory start conditions found using Auto Start, can be the same as those found using manual start.
     (b) The Auto Start system has equipment that collects input on problems. The equipment will automatically resequence the applicable control circuit to correct the unsatisfactory condition.
     (c) Usually, the FADEC system is resequenced after a total of 4 cycles. If the problem is not corrected after resequencing, the applicable diagnostic indications will be shown on the flight deck screen.
     (d) The FADEC system will automatically do the items that follow when a stall indication or overtemperature occur. It will also do these items when the starter air pressure is below 20 psi (1.4 bar) , or a hung start occurs.
       1 Stall indication or overtemperature
CAUTION: IF THE ENGINE STALLS OR HAS OVERTEMPERATURE AGAIN AND AGAIN, THE MALFUNCTION MUST BE CORRECTED.
         a A stall can be identified by an unusual change in the core speed acceleration.
         b It can also be identified by an unusually high EGT increase when compared to core speed.
         c An overtemperature happens when the engine EGT is more than 725 deg.C (1337 deg.F).
         d For either a stall or an overtemperature, the FADEC system will do the items that follow:
  • Fuel is shut off for 7 seconds.
  • Starter and ignition stay ON.
  • At the end of the 7 seconds, the fuel is turned back on but, the fuel schedule is reduced 7 percent.
  • If another stall or overtemperature occurs, the FADEC system repeats the sequence and reduces the fuel schedule by 7 percent more. The total amount that the fuel schedule has been reduced at this point is 14 percent.
  • If a stall or overtemperature occurs a third time, the FADEC system will repeat the sequence and reduce the fuel schedule 7 percent more. The total amount that the fuel schedule has been reduced at this point is 21 percent.
  • If a stall or overtemperature occurs a fourth time, the start will automatically be aborted and the applicable message will be indicated on the flight deck screen.
       2 Starter air pressure is below 20 psi (1.4 bar)
         a Low starter air pressure can be identified by a reduced N2 acceleration rate at 18-19 percent.
         b If the acceleration is below the threshold, but all of the other indications are in line with the limits, the start will continue.
         c If the acceleration is below the threshold and a stall or overtemperature is indicated, the start will be automatically aborted if in auto start mode.
         d The fuel will not be turned on if the starter air pressure is too low to motor the core to 22 percent N2, the start will be automatically aborted if in auto start mode.
       3 Hung start
         a If a rich hung start is detected (i.e. high fuel flow and rapid EGT rise), the ECU automatically applies a 7% fuel flow reduction
         b If a lean hung start is detected (i.e. low fuel flow and low EGT):
  • If engine acceleration ceases and there has been no reduction in the acceleration fuel schedule and there is no stall or overtemperature indication, the operator must abort the start.
  • If engine acceleration ceases and there has been a previous reduction in the acceleration fuel schedule and there is no stall or overtemperature indication, FADEC will automatically increase the acceleration fuel schedule to accomplish acceleration to idle.
       4 There is no fan speed (N1) indication
         a When the core has reached idle, and there is no N1 indication, a warning is sent to the flight deck. The operator must shut down the engine ; if on auto start mode the start will be automaticaly aborted if limits are exceeded.
NOTE: The FADEC system has been programmed with starter limits. If the sequences get close to any of these limits they will be taken into account before another start sequence or stall recovery is tried.
   (5) Unsatisfactory Operation above Idle
     (a) N1 and/or N2 transitory overspeed.
CAUTION: ALL OVERSPEED CONDITIONS MUST BE CORRECTED. ENGINE DAMAGE CAN BE CAUSED.
       1 Any fan speed (N1) of more than 102 percent or any core speed (N2) of more than 105 percent are overspeeds. The throttle must be retarded to prevent the engine speed from going higher than these limits.
     (b) Engine stalls
CAUTION: BE CAREFUL WHEN CONTINUING TO OPERATE AN ENGINE THAT HAS HAD A SEVERE COMPRESSOR STALL. IT CAN STALL AGAIN AND CAUSE MORE ENGINE DAMAGE.
CAUTION: IF THE EGT IS HIGH OR IT INCREASES FAST DURING A SLOW THROTTLE ADVANCE, SHUT DOWN THE ENGINE AND DO NOT CONTINUE OPERATION.
CAUTION: IF VIBRATION INCREASES OVER PREVIOUS LEVELS, SHUT DOWN THE ENGINE AND DO NOT CONTINUE OPERATION.
CAUTION: ALL STALLS MUST BE CORRECTED.
       1 Engine stalls are caused by the aerodynamic disruption of the normally smooth airflow through the compressor stages. This disruption can be caused by any of the items that follow:
       2 Foreign objects being ingested into the engine or FOD.
         a Cracked compressor blades.
         b Incorrect scheduling of the VSV.
       3 A stall can be identified by the items that follow:
         a Abnormal engine noises.
         b Loud bangs with flame coming from the engine inlet.
         c Performance parameters that are not stable.
         d Very slow or no throttle response.
       4 Compressor stalls can cause:
         a Fatigue cracks in the compressor blades.
         b They can also cause severe thermal deterioration of the hot section parts.
         c This damage can cause the engine performance to deteriorate or the engine to fail after a severe stall.
       5 Usually, the effects of stalls take time to appear and will make it harder to determine which specific stall has caused the damage.
       6 The effects of the stalls collect until they affect the engine durability, reliability, and operating cost.
       7 Make sure that you know the operational conditions that occurted at the time of the stall. This will help in fault isolation.
       8 When an engine stalls during acceleration or deceleration, the stall can be because of slow or sticking VSV operation. If a stall occurs during these conditions, and operating conditions permit it, the procedure that follows is recommended:
         a Retard the throttle to idle. This will clear the stall.
         b Monitor the EGT and N2 while they decrease.
         c Advance the throttle slowly to find out if the stall will occur again.
         d Monitor the N1, N2, vibration, fuel flow, and EGT.
         e If the stall does not occur again and the N2 and EGT indications are normal, continue engine operation.
         f Shut down the engine if the stall occurs again or does not clear properly.
     (c) Engine flameout
       1 An engine flameout, can be identified by an immediate decrease in EGT, N2, fuel flow, and oil pressure. This will be closely followed by a decrease in N1.
       2 The FADEC system has a flameout detector that automatically starts the ignition when it senses a flameout.
       3 If an engine light-off does not occur, a complete start sequence must be initiated.
       4 Use the procedure that follows when the cause of the flameout is not known:
         a Put the throttle control levers of the engines 1 and 2 to the idle stop position (zero on the graduated sector).
       5 Another start may be tried if the engine indications before the flameout, and the examination after the flameout, do not show an engine malfunction or failure.
     (d) Oil system malfunction
CAUTION: BE CAREFUL WHEN OPERATING AN ENGINE WITH OIL PRESSURE THAT IS OVER OR UNDER THE NORMAL PRESSURE RANGE. ENGINE DAMAGE CAN RESULT.
       1 During cold conditions, it is permitted to go over 45 psi (3.1 bar) during starts.
       2 It is also permitted to go over 90 psi (6.2 bar) at takeoff before the engine warms up.
       3 If oil pressure is more than 90 psi (6.2 bar) during steady-state operation, it is usually an indication of an engine malfunction. Unless all other parameters are normal and it is definitely a known pressure indication error.
       4 Examine the cause of any oil pressure fluctuation, or when the pressure varies more or less than 5 psi (0.3 bar) from a steady-state operating pressure.
       5 Operating an engine with the oil pressure less than the minimum is not permitted.
       6 Oil system malfunctions, and the effects of the malfunctions, must be corrected.
     (e) Scavenge oil overtemperature
CAUTION: OIL TEMPERATURES THAT ARE MORE THAN THE NORMAL STEADY-STATE TEMPERATURES CAN INDICATE A SYSTEM MALFUNCTION. MONITOR THIS CONDITION CLOSELY OR ENGINE DAMAGE CAN BE CAUSED.
       1 The supply oil temperature limit for continuous operation is 140 deg.C (284 deg.F).
       2 Transient operation to but not over 155 deg.C (311 deg.F) is permitted for not more than 15 minutes.
       3 Temperatures above 140 deg.C (284 deg.F) must be written in the Aircraft Log.
     (f) Engine overtemperature
       1 Obey the EGT limits in (Ref. AMM TASK 72-00-00-200-003). Any temperatures more than these are overtemperatures.
       2 Write the length of time an overtemperature lasts, and the temperature reached, in the Aircraft Log. See (Ref. AMM TASK 72-00-00-200-003) for unscheduled inspections after engine overtemperature.
     (g) Internal engine fire
CAUTION: TRY TO EXTINGUISH INTERNAL FIRES BY MOTORING THE ENGINE FIRST. USE FIRE EXTINGUISHING AGENTS ONLY WHEN MOTORING DOES NOT WORK. IF EXTINGUISHING AGENTS ARE USED, A MAJOR INSPECTION CAN BE NECESSARY.
       1 An internal engine fire (post-shutdown burning), can be identified by a failure of the EGT to go down after placing ENG MASTER 1(2) control switch in the OFF position. If an internal engine fire occurs during ground operation, use the procedure that follows:
       2 On the ENG panel 115VU:
  • Set the ENG/MODE/CRANK/NORM/IGN/START selector switch to CRANK.
    On the overhead CTL & IND panel 22VU:
  • Push the ENG/MAN START/1(2) pushbutton switch.
NOTE: Dry motor the engine until all indications of a fire have been removed.
NOTE: The start valve will automatically reopens when N2 is below 20 percent.
     (h) External engine fire
       1 The warnings below operate when there is an external engine fire:
         a On the overhead panel 1WD:
  • The ENG 1(2) FIRE pushbutton switch comes on.
         b The continuous repetitive chime operates.
         c The MASTER WARN lights come on.
         d On the upper ECAM display unit:
  • A message and the applicable procedure come into view.
         e On the ENG panel 115VU:
  • The applicable FIRE legend comes on.
       2 When there is an external engine fire, do this procedure:
         a Put the throttle control levers of the engines 1 and 2 in the idle stop position (zero on the graduated sector).
         b On the ENG panel 115VU:
  • Set the ENG/MASTER 1(2) switch to OFF.
         c On the panel 1WD, push the ENG 1(2) FIRE pushbutton switch:
NOTE: After operation of the ENG1(2) FIRE pushbutton switch, do the operational test of the hydraulic fire shut-off valves (Ref. AMM TASK 29-10-00-710-001).
  • The SQUIB legends of the applicable AGENT 1 and AGENT 2 pushbutton switches come on.
  • The audio warning stops.
         d On the panel 1WD, push the AGENT 1 and 2 pushbutton switches:
  • After not many seconds, the DISCH legends of this pushbutton switches comes on.
         e Open the fan cowl doors and if the fire is not completely extinguished, extinguish the fire with the ground fire extinguishers.
         f If fire occurs in FAN zone with fan cowl doors opened, use the fire extinguishers that are on the ground, when permitted to do so by the approved person.
NOTE: The aircraft fire extinguishers do not have an effect with the cowls open or removed.
         g Replace the nacelle fire extinguisher bottles if they are used.
         h Do the procedure (Ref. AMM TASK 72-00-00-200-002).
         i Examine the engine and the nacelle for fire damage:
  • Repair or replace the nacelle if it is necessary.
  • Repair or replace the engine if it is necessary.
         j Find and correct the cause of the fire warning.
[Rev.10 from 2021] 2026.04.01 02:21:38 UTC