Trent700 Core Ice Removal.
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Trent700 Core Ice Removal.
Could somebody in the know please explain what the procedure is when “ Manual De-icing” is required when the Trent 700 experiences ENGINE CORE icing in Freezing Fog conditions. I am referring to the procedure that is required to be carried out by maintenance.
Secondly why does a bore scope need to be carried out after 10 flights if total taxi time exceeds 45 mins but not 60 when the core ice shedding procedure is not carried out.
Secondly why does a bore scope need to be carried out after 10 flights if total taxi time exceeds 45 mins but not 60 when the core ice shedding procedure is not carried out.
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MM procedure to manually de-ice Trent core
Ground operation in freezing fog.
NOTE:
For this procedure, freezing fog is specified as moisture that can be seen which limits the view to less than 3280 ft (1000 m) when the OAT is less than 34°F (1°C).
NOTE:
The selection of engine anti-ice to ON does not stop the buildup of ice in the engine core inlet.
(a)
If you must operate the engine in freezing fog, obey these instructions.
1)
You must not operate the engine for longer than a total of 45 minutes, in one or a number of shorter operations (unless the engine core inlet is de-iced during that period).
NOTE:
If you do the procedure to de-ice the engine core inlet during the 45 minute limit of operation, the 45 minute period starts again (from the end of the de-ice procedure).
2)
If the aircraft landed in these conditions, you must include the time period from when the aircraft landed until shutdown in the count.
3)
You must monitor and record the length of time of each engine operation in these conditions.
4)
You must add the length of each engine operation together and record the total time of operation in these conditions.
5)
You must do one of the core inlet de-icing procedures (see below) before the end of each 45 minutes of total operation.
NOTE:
Rolls Royce recommends that the aircraft is put back into operation with each engine core sufficiently de-iced for a minimum of 35 minutes operation (in freezing fog). It is recommended that you increase the engine speed, for the applicable time period, in the last 10 minutes of the ground test/operation. Alternatively, manually de-ice the engine core inlet after shutdown Manually De-Ice the Engine Core Inlet, TASK 12-33-03-600-801.
(b)
The engine core inlet de-icing procedures.
1)
The OAT is above (warmer) or equal to 21°F (-6°C), increase the engine(s) to 50 percent N1 for 60 seconds.
NOTE:
This procedure will safely release the ice from the core inlet components. Record in the applicable log that this de-ice procedure has been done.
2)
If you cannot do the procedure above, (or the engine has been operated for longer than the 45 minute limit), stop the engine and manually de-ice the engine core inlet Manually De-Ice the Engine Core Inlet, TASK 12-33-03-600-801.
NOTE:
Record in the applicable log that this de-ice procedure has been done.
(c)
When all ground tests/operations are completed, do the steps that follow:
1)
Calculate the time that remains available to the flight crew for departure in freezing fog conditions.
2)
Give the time that remains as a maximum time limit to the flight crew
Manually De-Ice the Engine Core Inlet
A.
General
(1)
This task gives the instructions to remove ice from the variable inlet guide vanes (VIGVs) and the inlet area of the egnine core for a static engine. A locally made cover is put on the engine exhaust only. Air from an air start unit is then supplied to the engine core through an opening/adapter in the cover.
(2)
The function of the cover is to make sure that the warm air supply (into the aft of the engine) goes forward through the engine core. This air transmits the heat to the VIGVs and the inlet area of the engine core. It is permitted to have some leakage of air, but if there is too much leakage, it will increase the time that is necessary to complete the procedure.
(3)
It is important that the type of cover that you use can operate without damage up to a temperature of 180°C (356 °F). It must also have an adapter installed to it that will connect to the air supply hose from an COM-2475 air start unit .
NOTE:
A locally made cover to this specified is referred to task of the Procedure to Dry the Engine, TASK 71-00-03-600-813-R00.
(4)
It is recommended that you do not point the aircraft into a strong wind during this procedure. A strong wind can have a bad effect on the flow of warm air from the aft of the engine.
Pull some CB's then
Install the exhaust sleeve cover:
(a)
Make an exhaust sleeve cover with an adapter to connect the air supply hose from the COM-2475 air start unit .
(b)
Get access to the core engine exhaust sleeve.
(c)
Install the exhaust sleeve cover on the exhaust sleeve.
(d)
Install the adapter on the cover.
(e)
Move the COM-2475 air start unit to the rear of the engine and attach the air supply hose to the adapter on the nozzle cover.
SUBTASK 12-33-03-660-001
CAUTION:
THE HOT AIR SUPPLY SHOULD ONLY BE SWITCHED ON WHEN THE EXHAUST NOZZLE COVER IS CORRECTLY INSTALLED TO INJECT HOT AIR INTO THE CORE ENGINE. COMPONENTS IN THE BYPASS DUCT ARE NOT TEMPERATURE CAPABLE TO 160°C (320°F). MAKE SURE THE HOT AIR IS NOT DIRECTED AT ANY COMPONENTS OUTSIDE THE CORE COMPONENTS. IF THE HOT AIR IS DIRECTED TO THE OUTSIDE COMPONENTS, IT CAN CAUSE DAMAGE TO THE COMPONENTS.
(2)
Do these steps to de-ice the core engine inlet area and the VIGVs:
(a)
Operate the COM-2475 air start unit and put warm air through the engine.
NOTE:
The air supply should be between 140-160 pounds/minute (63.50- 72.57 kilograms/minute) at approximately 10 psi (68.95 KPa) and 160 °C (320 °F). If you use a low flow rate or low temperature, it will require a longer time to de-ice the core engine inlet and the VIGVs.
(b)
Operate the COM-2475 air start unit until all the ice has been removed from the VIGVs.
NOTE:
A minimum time of 40-60 minutes will be necessary to complete this procedure. The actual time will be a function of ambient air temperature and the level of accumulated ice.
(c)
Stop the COM-2475 air start unit .
(d)
Put a COM-4316 6 mm flexible olympus borescope through the gaps in the LP compressor and examine the surfaces of the VIGVs.
NOTE:
The VIGV's can be examined from the front of the engine through the fan with a flexible borescope. It is not necessary to open the thrust reversers and have access to the borescope ports.
(e)
Make sure that the surfaces of the VIGVs are free of ice.
(f)
Use a G00219 cloth or G00116 sponge to remove any residual water.
(g)
If the VIGVs are not completely clear of ice, remove the COM-4316 6 mm flexible olympus borescope and reapply the hot air again.
(h)
If the VIGV's are completely clear of ice, remove the COM-4316 6 mm flexible olympus borescope and put the airplane back to its usual condition.
1)
Remove all tools, G00219 cloth or G00116 sponge from the engine.
NOTE:
For this procedure, freezing fog is specified as moisture that can be seen which limits the view to less than 3280 ft (1000 m) when the OAT is less than 34°F (1°C).
NOTE:
The selection of engine anti-ice to ON does not stop the buildup of ice in the engine core inlet.
(a)
If you must operate the engine in freezing fog, obey these instructions.
1)
You must not operate the engine for longer than a total of 45 minutes, in one or a number of shorter operations (unless the engine core inlet is de-iced during that period).
NOTE:
If you do the procedure to de-ice the engine core inlet during the 45 minute limit of operation, the 45 minute period starts again (from the end of the de-ice procedure).
2)
If the aircraft landed in these conditions, you must include the time period from when the aircraft landed until shutdown in the count.
3)
You must monitor and record the length of time of each engine operation in these conditions.
4)
You must add the length of each engine operation together and record the total time of operation in these conditions.
5)
You must do one of the core inlet de-icing procedures (see below) before the end of each 45 minutes of total operation.
NOTE:
Rolls Royce recommends that the aircraft is put back into operation with each engine core sufficiently de-iced for a minimum of 35 minutes operation (in freezing fog). It is recommended that you increase the engine speed, for the applicable time period, in the last 10 minutes of the ground test/operation. Alternatively, manually de-ice the engine core inlet after shutdown Manually De-Ice the Engine Core Inlet, TASK 12-33-03-600-801.
(b)
The engine core inlet de-icing procedures.
1)
The OAT is above (warmer) or equal to 21°F (-6°C), increase the engine(s) to 50 percent N1 for 60 seconds.
NOTE:
This procedure will safely release the ice from the core inlet components. Record in the applicable log that this de-ice procedure has been done.
2)
If you cannot do the procedure above, (or the engine has been operated for longer than the 45 minute limit), stop the engine and manually de-ice the engine core inlet Manually De-Ice the Engine Core Inlet, TASK 12-33-03-600-801.
NOTE:
Record in the applicable log that this de-ice procedure has been done.
(c)
When all ground tests/operations are completed, do the steps that follow:
1)
Calculate the time that remains available to the flight crew for departure in freezing fog conditions.
2)
Give the time that remains as a maximum time limit to the flight crew
Manually De-Ice the Engine Core Inlet
A.
General
(1)
This task gives the instructions to remove ice from the variable inlet guide vanes (VIGVs) and the inlet area of the egnine core for a static engine. A locally made cover is put on the engine exhaust only. Air from an air start unit is then supplied to the engine core through an opening/adapter in the cover.
(2)
The function of the cover is to make sure that the warm air supply (into the aft of the engine) goes forward through the engine core. This air transmits the heat to the VIGVs and the inlet area of the engine core. It is permitted to have some leakage of air, but if there is too much leakage, it will increase the time that is necessary to complete the procedure.
(3)
It is important that the type of cover that you use can operate without damage up to a temperature of 180°C (356 °F). It must also have an adapter installed to it that will connect to the air supply hose from an COM-2475 air start unit .
NOTE:
A locally made cover to this specified is referred to task of the Procedure to Dry the Engine, TASK 71-00-03-600-813-R00.
(4)
It is recommended that you do not point the aircraft into a strong wind during this procedure. A strong wind can have a bad effect on the flow of warm air from the aft of the engine.
Pull some CB's then
Install the exhaust sleeve cover:
(a)
Make an exhaust sleeve cover with an adapter to connect the air supply hose from the COM-2475 air start unit .
(b)
Get access to the core engine exhaust sleeve.
(c)
Install the exhaust sleeve cover on the exhaust sleeve.
(d)
Install the adapter on the cover.
(e)
Move the COM-2475 air start unit to the rear of the engine and attach the air supply hose to the adapter on the nozzle cover.
SUBTASK 12-33-03-660-001
CAUTION:
THE HOT AIR SUPPLY SHOULD ONLY BE SWITCHED ON WHEN THE EXHAUST NOZZLE COVER IS CORRECTLY INSTALLED TO INJECT HOT AIR INTO THE CORE ENGINE. COMPONENTS IN THE BYPASS DUCT ARE NOT TEMPERATURE CAPABLE TO 160°C (320°F). MAKE SURE THE HOT AIR IS NOT DIRECTED AT ANY COMPONENTS OUTSIDE THE CORE COMPONENTS. IF THE HOT AIR IS DIRECTED TO THE OUTSIDE COMPONENTS, IT CAN CAUSE DAMAGE TO THE COMPONENTS.
(2)
Do these steps to de-ice the core engine inlet area and the VIGVs:
(a)
Operate the COM-2475 air start unit and put warm air through the engine.
NOTE:
The air supply should be between 140-160 pounds/minute (63.50- 72.57 kilograms/minute) at approximately 10 psi (68.95 KPa) and 160 °C (320 °F). If you use a low flow rate or low temperature, it will require a longer time to de-ice the core engine inlet and the VIGVs.
(b)
Operate the COM-2475 air start unit until all the ice has been removed from the VIGVs.
NOTE:
A minimum time of 40-60 minutes will be necessary to complete this procedure. The actual time will be a function of ambient air temperature and the level of accumulated ice.
(c)
Stop the COM-2475 air start unit .
(d)
Put a COM-4316 6 mm flexible olympus borescope through the gaps in the LP compressor and examine the surfaces of the VIGVs.
NOTE:
The VIGV's can be examined from the front of the engine through the fan with a flexible borescope. It is not necessary to open the thrust reversers and have access to the borescope ports.
(e)
Make sure that the surfaces of the VIGVs are free of ice.
(f)
Use a G00219 cloth or G00116 sponge to remove any residual water.
(g)
If the VIGVs are not completely clear of ice, remove the COM-4316 6 mm flexible olympus borescope and reapply the hot air again.
(h)
If the VIGV's are completely clear of ice, remove the COM-4316 6 mm flexible olympus borescope and put the airplane back to its usual condition.
1)
Remove all tools, G00219 cloth or G00116 sponge from the engine.
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Spanners,
Is the start of timing for taxi out stated anywhere? Or should i simply assume that the aggregate resumes at starting of the first engine?
From the AMM you've posted it seems that if i fail to do the ice shed between the 35-45 min aggregate, then its a mandatory return to gate for a manual de-ice. Am i straight on this?
Thanks mate, see you on the line
Mach
Thanks for the post- good question.
In reference to your last question/sentence- is this an airline specific procedure? Just asking as it seems to go against the AMM above and neither have i come across it in our FCOM
HJ
Is the start of timing for taxi out stated anywhere? Or should i simply assume that the aggregate resumes at starting of the first engine?
From the AMM you've posted it seems that if i fail to do the ice shed between the 35-45 min aggregate, then its a mandatory return to gate for a manual de-ice. Am i straight on this?
Thanks mate, see you on the line
Mach
Thanks for the post- good question.
In reference to your last question/sentence- is this an airline specific procedure? Just asking as it seems to go against the AMM above and neither have i come across it in our FCOM
HJ
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Core Ice Removal
The second question refers to the Trent800(B777) as per OMB recommended by Boeing and RR. However it appears that both the 700&800 have the same problem. So Herc Jerk when you refer to the FCOM I assume your talking Airbus. However several customers have apparently requested to be able to take off upto 60 mins total taxi time without carrying out the core ice shedding procedure. Apparently this is ok provided a borescope is carried out within 10 flights.
