Windmilling engine
Join Date: Jan 2001
Location: Dunstable, Beds UK
Posts: 545
Likes: 0
Received 0 Likes
on
0 Posts
Speedbird,
Yes we had same procedure for runaways on the DC6.
I also went to a DC3 that had the same problem on T/O out of Birmingham. Front bearing broke up and oil debris bloocked the coarse pitch oil line. The last RPM the crew saw was 3000 + !
They landed back on and the whole of the front of the engine was bright blue !!
The DC procedure was first of all try to feather but after 3,000 rpm the feathering pump bows out. Then you did the low and slow which was suppose the reduce the RPM to a point where the feathering pump regained interest. Finally shut the oil off to freeze the bearings ( tuning away from the offending engine !)
Incidentally the hydraulic pumps mentioned above are swash plate type with no demand ( After engine shut down) go to zero pitch and do not produce pressure
Yes we had same procedure for runaways on the DC6.
I also went to a DC3 that had the same problem on T/O out of Birmingham. Front bearing broke up and oil debris bloocked the coarse pitch oil line. The last RPM the crew saw was 3000 + !
They landed back on and the whole of the front of the engine was bright blue !!
The DC procedure was first of all try to feather but after 3,000 rpm the feathering pump bows out. Then you did the low and slow which was suppose the reduce the RPM to a point where the feathering pump regained interest. Finally shut the oil off to freeze the bearings ( tuning away from the offending engine !)
Incidentally the hydraulic pumps mentioned above are swash plate type with no demand ( After engine shut down) go to zero pitch and do not produce pressure
Join Date: Jul 2005
Location: OZ
Posts: 580
Likes: 0
Received 0 Likes
on
0 Posts
AeroTech..to add to the topic.
Off the top of my head..
The windmilling procedure you ask about is P&W centric as "cod liver oil" accurately describes the need to lube the pump fcu/fmu during a dry motor on the ground.
In the case of wind milling the oil pump is also turning the oil is not getting hot due to no combustion there for cooling the fuel (in fuel oil heat exchangers) which is already at a lower pressure do to wind mill bypass valves in the ffr/fmu/hmu/fcu etc
The fuel on for extended wind milling procedure must be for early jt9d-3a etc and 727s perhaps due to the FP 12 pressure (control fuel for vanes and valves) which will always regulate to its designed pressure approx 800 psi. and is only at a lower pressure due to N2 rpm ie 800 psi at 15% N2 and above ( I think)
Hope this helps
Off the top of my head..
The windmilling procedure you ask about is P&W centric as "cod liver oil" accurately describes the need to lube the pump fcu/fmu during a dry motor on the ground.
In the case of wind milling the oil pump is also turning the oil is not getting hot due to no combustion there for cooling the fuel (in fuel oil heat exchangers) which is already at a lower pressure do to wind mill bypass valves in the ffr/fmu/hmu/fcu etc
The fuel on for extended wind milling procedure must be for early jt9d-3a etc and 727s perhaps due to the FP 12 pressure (control fuel for vanes and valves) which will always regulate to its designed pressure approx 800 psi. and is only at a lower pressure due to N2 rpm ie 800 psi at 15% N2 and above ( I think)
Hope this helps
Thread Starter
Join Date: Jun 2005
Location: USA
Posts: 179
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
Bolty McBolt, thank you for your post.
1-So far, nobody posted information regarding engine parameters (oil temperature and pressure, N1 & N2) during windmill (it seems it is difficult to remember such parameters during real windmill since it is rare, or at sim. It will be very helpful if someone have DFDR data during windmill :like the case the Air Transat, Gimly glider, BA 747 flying through vulcano ash, or other cases. I don't know if during such case (total loss of electricity) aircraft data (engine included) are recorded or not?
2-I would like also information (if possible) about windmilling engine during ferry flights.
Does low oil pressure and oil viscosity affect the lubrication of engine during extended windmill?
3-In the same context of windmilling engines (all engines), what components (besides the main flight control like aileron, etc) are provided by the RAT : both electric components and secondary flight control?(we suppose that the RAT provide hydraulic and electric power).
Thank you for your help.
Best regards.
Bolty McBolt, thank you for your post.
1-So far, nobody posted information regarding engine parameters (oil temperature and pressure, N1 & N2) during windmill (it seems it is difficult to remember such parameters during real windmill since it is rare, or at sim. It will be very helpful if someone have DFDR data during windmill :like the case the Air Transat, Gimly glider, BA 747 flying through vulcano ash, or other cases. I don't know if during such case (total loss of electricity) aircraft data (engine included) are recorded or not?
2-I would like also information (if possible) about windmilling engine during ferry flights.
Does low oil pressure and oil viscosity affect the lubrication of engine during extended windmill?
3-In the same context of windmilling engines (all engines), what components (besides the main flight control like aileron, etc) are provided by the RAT : both electric components and secondary flight control?(we suppose that the RAT provide hydraulic and electric power).
Thank you for your help.
Best regards.
Join Date: Jul 2005
Location: OZ
Posts: 580
Likes: 0
Received 0 Likes
on
0 Posts
HI
AeroTech
I have Only 3 questions.. WHY WHY WHY???
In the modern aircraft/airline ONE of the most important KPIs are measured by in flight shut downs... AS in the most UNdesireable thing to happen to an airline or Engine manufacturer...
There are very few things that cause a pilot to shut down an engine..(perhaps more but i can't think of them at this second)
1 Low oil pressure
2 Engine Vibration
3 Out of fuel to cause engine to shut down...
The 3 things above cause many ground inspections when the aircraft finally meets mother earth again.
You never mention the cause of the wind milling???
What does it matter as the engine has been shut down in flight..= no goood/US out of oil dead useless etc etc etc
Why would anyone care about the parameters of a dead engine??IT is dead not producing thrust...
AS far as your Questions about a Ram Air Turbine...
Which aircraft..What about it? And why was it deployed??
I will be happy to enlighten you with all correct answers from AMMs but not until you ask the rifght questions..
Please don't take offence at my tone for this is a fault of many a tech crew..Not giving the correct info/ situation about an inflight defect
Regards
Bolty
AeroTech
I have Only 3 questions.. WHY WHY WHY???
In the modern aircraft/airline ONE of the most important KPIs are measured by in flight shut downs... AS in the most UNdesireable thing to happen to an airline or Engine manufacturer...
There are very few things that cause a pilot to shut down an engine..(perhaps more but i can't think of them at this second)
1 Low oil pressure
2 Engine Vibration
3 Out of fuel to cause engine to shut down...
The 3 things above cause many ground inspections when the aircraft finally meets mother earth again.
You never mention the cause of the wind milling???
What does it matter as the engine has been shut down in flight..= no goood/US out of oil dead useless etc etc etc
Why would anyone care about the parameters of a dead engine??IT is dead not producing thrust...
AS far as your Questions about a Ram Air Turbine...
Which aircraft..What about it? And why was it deployed??
I will be happy to enlighten you with all correct answers from AMMs but not until you ask the rifght questions..
Please don't take offence at my tone for this is a fault of many a tech crew..Not giving the correct info/ situation about an inflight defect
Regards
Bolty
Thread Starter
Join Date: Jun 2005
Location: USA
Posts: 179
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
Bolty (thank you for your post),
I was wondering about windmilling engine, which means no shafts seizure: any kind of engine shutdown. The cause may be low oil pressure, high oil temperature, high EGT, engine vibration, engine surge, or even start valve open in flight for certain engines
(this is precautionary engine shutdown, kind of voluntary shutdown). Engine flame-out (kind of involuntary engine shutdown) caused by fuel (out of fuel), flying through volcanic ash or severe weather conditions (heavy hail/rain, strong turbulence), or even after engine fire (shafts turning). So the cause does not matter (at least for me): as I said in my first post, I am doing kind of research (for my study).
So I care about a shut-off engine parameters (in flight), any information available are very helpful even from DFDR data.
I was wondering about the automatic use of the RAT (that's why I said all engines windmilling, or even with manual but with all engines flame-out) and the components that are provided by hydraulic and electric components (besides the main flight controls: rudder, aileron, elevator). The raison I asked this, because I was thinking about the landing : may be flaps up, no reversers, no spoilers, and may be no brakes (I am not sure if these components are provided or no by hydraulic, because the power of the RAT seems limited mainly at landing).
Also the battery supplies electricty to certain important flight instruments, does the RAT provide electricity to other flight instruments, or other devices? If yes, what intruments or devices?
I was wondering mostly about any Boeing and Airbus aircrafts fitted with RAT (preferably the recents, but other aircrafts are welcome).
I hope these information will facilitate my questions, please Bolty
or other don't hesitate if you want more clarifications (I think it is clear now
unless Bolty want to give me hard time, I had enough of it with the RAT 
. By the way I have a whole of bunch of questions, but I try to post them separately for less confusion.
I get a second tought to your previous answer concerning the cooling and the lubrication of the fuel pump and the HMU (I am sorry, but I still have some interrogations
The fuel cools engine oil (when engine is operative) because the fuel is renewed (it is consumed) and the fuel is colder than the oil.
During windmill the fuel is trapped, and the oil is circulating in closed circuit (not renewed). When the oil is getting hot because it cools the fuel, how the oil is cooled mainly during extended windmill ( may be up to 207 minutes like in 777, I don't know if it is still the maximum diversion time; or may be more for quadjets since they are allowed to continue the flight in case of 1 engine shutdown). For certain engine like CFM56, the fuel goes through the IDG oil/fuel heat exchanger first, then the fuel/oil heat exchanger: i don't know if the fuel get colder (may be the opposite?) when it flows through the IDG oil/fuel cooler? because IDG is turning and the IDG oil is circulating in closed circuit even though the generator is tripped off (I think the IDG is not disconnected in case engine shutdown, may be even in case of engine fire, correct me if I am wrong).
Another interrogation: if the fuel is cooled by oil in the fuel/oil heat exchanger during the windmill, the fuel could be also cooled by oil during dry motoring. So why the AMM recommends to perform a cooling and lubricating procedure for the fuel pump and the HMU during dry motoring? even though the dry motoring lasts few minutes but the windmill may last hours.
Thank you for reading my long post, I hope it is not boring ( feedback appreciated)
Best regards.
Bolty (thank you for your post),
I was wondering about windmilling engine, which means no shafts seizure: any kind of engine shutdown. The cause may be low oil pressure, high oil temperature, high EGT, engine vibration, engine surge, or even start valve open in flight for certain engines
(this is precautionary engine shutdown, kind of voluntary shutdown). Engine flame-out (kind of involuntary engine shutdown) caused by fuel (out of fuel), flying through volcanic ash or severe weather conditions (heavy hail/rain, strong turbulence), or even after engine fire (shafts turning). So the cause does not matter (at least for me): as I said in my first post, I am doing kind of research (for my study).
So I care about a shut-off engine parameters (in flight), any information available are very helpful even from DFDR data.
I was wondering about the automatic use of the RAT (that's why I said all engines windmilling, or even with manual but with all engines flame-out) and the components that are provided by hydraulic and electric components (besides the main flight controls: rudder, aileron, elevator). The raison I asked this, because I was thinking about the landing : may be flaps up, no reversers, no spoilers, and may be no brakes (I am not sure if these components are provided or no by hydraulic, because the power of the RAT seems limited mainly at landing).
Also the battery supplies electricty to certain important flight instruments, does the RAT provide electricity to other flight instruments, or other devices? If yes, what intruments or devices?
I was wondering mostly about any Boeing and Airbus aircrafts fitted with RAT (preferably the recents, but other aircrafts are welcome).
I hope these information will facilitate my questions, please Bolty
or other don't hesitate if you want more clarifications (I think it is clear now
unless Bolty want to give me hard time, I had enough of it with the RAT . By the way I have a whole of bunch of questions, but I try to post them separately for less confusion.I get a second tought to your previous answer concerning the cooling and the lubrication of the fuel pump and the HMU (I am sorry, but I still have some interrogations
The fuel cools engine oil (when engine is operative) because the fuel is renewed (it is consumed) and the fuel is colder than the oil.
During windmill the fuel is trapped, and the oil is circulating in closed circuit (not renewed). When the oil is getting hot because it cools the fuel, how the oil is cooled mainly during extended windmill ( may be up to 207 minutes like in 777, I don't know if it is still the maximum diversion time; or may be more for quadjets since they are allowed to continue the flight in case of 1 engine shutdown). For certain engine like CFM56, the fuel goes through the IDG oil/fuel heat exchanger first, then the fuel/oil heat exchanger: i don't know if the fuel get colder (may be the opposite?) when it flows through the IDG oil/fuel cooler? because IDG is turning and the IDG oil is circulating in closed circuit even though the generator is tripped off (I think the IDG is not disconnected in case engine shutdown, may be even in case of engine fire, correct me if I am wrong).
Another interrogation: if the fuel is cooled by oil in the fuel/oil heat exchanger during the windmill, the fuel could be also cooled by oil during dry motoring. So why the AMM recommends to perform a cooling and lubricating procedure for the fuel pump and the HMU during dry motoring? even though the dry motoring lasts few minutes but the windmill may last hours.
Thank you for reading my long post, I hope it is not boring ( feedback appreciated)
Best regards.
Join Date: Nov 2002
Location: Australia
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
Bolty McB,
I've only done one extended IFSD, on an RB211. HP Fuel through a failed pump seal poured all the oil out of the breather with predictable results (overheat, low press etc). Engine windmilled for approx 4 hrs, ADP hydraulic pump operated perfectly, EDP cooling same (switch selection to enable case drain cooling of pump). Engine changed, inspected and back to service in no time. Thanks Boeing & RR!
The technical knowledge displayed on this thread boggles my remaining braincell, but I feel I must enlighten you on the RAT, nonmally fitted to aircraft whose manufacturers have omitted to fit enough engines.
The definition of a RAT is " An unpreposessing creature of unlimited low cunning, capable of survival in hostile environments, but can be savage when threatened or cornered'.
The smaller, less agressive cousin is the MOUSE, 'A timid inoffensive creature, capable of living in close proximity to other species with limited impact.'
There is normally only one RAT on an aircraft. He occupies the Left hand seat.
The MOUSE occupies the right hand seat, devoting his time to actively plotting and encouraging the premature retirement/downfall/demise of the RAT, so that he may assume his justified seat.
Hope that's cleared it up!
The best way to have extra generators, Hyd. pumps etc. is to have them self powered, a couple of RB211's might be nice in the middle of the Pacific.......................
Good luck with the project
I've only done one extended IFSD, on an RB211. HP Fuel through a failed pump seal poured all the oil out of the breather with predictable results (overheat, low press etc). Engine windmilled for approx 4 hrs, ADP hydraulic pump operated perfectly, EDP cooling same (switch selection to enable case drain cooling of pump). Engine changed, inspected and back to service in no time. Thanks Boeing & RR!
The technical knowledge displayed on this thread boggles my remaining braincell, but I feel I must enlighten you on the RAT, nonmally fitted to aircraft whose manufacturers have omitted to fit enough engines.
The definition of a RAT is " An unpreposessing creature of unlimited low cunning, capable of survival in hostile environments, but can be savage when threatened or cornered'.
The smaller, less agressive cousin is the MOUSE, 'A timid inoffensive creature, capable of living in close proximity to other species with limited impact.'
There is normally only one RAT on an aircraft. He occupies the Left hand seat.
The MOUSE occupies the right hand seat, devoting his time to actively plotting and encouraging the premature retirement/downfall/demise of the RAT, so that he may assume his justified seat.
Hope that's cleared it up!
The best way to have extra generators, Hyd. pumps etc. is to have them self powered, a couple of RB211's might be nice in the middle of the Pacific.......................
Good luck with the project
Thread Starter
Join Date: Jun 2005
Location: USA
Posts: 179
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
Fragman88, thank you for your post
quote:
--------------------------------------------------------------------------------
I've only done one extended IFSD, on an RB211. HP Fuel through a failed pump seal poured all the oil out of the breather with predictable results (overheat, low press etc). Engine windmilled for approx 4 hrs, ADP hydraulic pump operated perfectly, EDP cooling same (switch selection to enable case drain cooling of pump). Engine changed, inspected and back to service in no time. Thanks Boeing & RR!
--------------------------------------------------------------------------------
I am not familiar with the RB211 and the hydraulic system of the aircraft you was flying. Can you please explain me the anomaly of the engine and the EDP cooling in details, I didn't inderstand your statement : switch selection to enable case drain cooling of pump?.
What is the air source that provides the ADP?( normal mode and standby mode?). I don't know if the standby mode exists: I am wondering if the failed engine is not providing air normally to the ADP, can this pump still be provided by the operating engines or the APU (normally or alternatively)?
In the failed engine (during windmill), probably the IDG was not online? should the EDP (if operative) still providing 3000 PSI, but with low hydraulic flow rate? (I don't know if my statement is right or wrong for the RB211 windmilling engine? what do you think?
Do you still remember N1, N2, N3 of the windmilling engine and the operating engines?
Thank you.
Best regards.
Fragman88, thank you for your post
quote:
--------------------------------------------------------------------------------
I've only done one extended IFSD, on an RB211. HP Fuel through a failed pump seal poured all the oil out of the breather with predictable results (overheat, low press etc). Engine windmilled for approx 4 hrs, ADP hydraulic pump operated perfectly, EDP cooling same (switch selection to enable case drain cooling of pump). Engine changed, inspected and back to service in no time. Thanks Boeing & RR!
--------------------------------------------------------------------------------
I am not familiar with the RB211 and the hydraulic system of the aircraft you was flying. Can you please explain me the anomaly of the engine and the EDP cooling in details, I didn't inderstand your statement : switch selection to enable case drain cooling of pump?.
What is the air source that provides the ADP?( normal mode and standby mode?). I don't know if the standby mode exists: I am wondering if the failed engine is not providing air normally to the ADP, can this pump still be provided by the operating engines or the APU (normally or alternatively)?
In the failed engine (during windmill), probably the IDG was not online? should the EDP (if operative) still providing 3000 PSI, but with low hydraulic flow rate? (I don't know if my statement is right or wrong for the RB211 windmilling engine? what do you think?
Do you still remember N1, N2, N3 of the windmilling engine and the operating engines?
Thank you.
Best regards.
