Windmilling engine

[AeroTech]

Hi,

I am looking for certain information (for my study), it will be very nice if you can help me (besides I don't have manuals).

For certain old aircrafts, a windmill procedure is applied after engine shutdown (not engine fire) each 30 minutes of windmill for B 727-200, or for 3 minutes at one hour intervals for B 747. This procedure allows the flow of the fuel through the fuel pump and the FCU, then this fuel is dumped. I guess this fuel will lubricate these 2 components during the windmill.
Is there any similar windmill procedure for other aircrafts (Boeing & Airbus) mainly for extended windmill?

-During windmill, what will be the engine parameters :oil temperature, oil pressure, N1 & N2 ? (if possible, may be it is difficult to remember these information during windmill, because they may vary according to weight, speed, etc ). The hydraulic pump may still deliver some hydraulic pressure? Is it sufficient to actuate the flight controls?

Thank you in advance.
Best regards.

[Rainboe]

I've flown B737 200/400, B747 100/200/400, Pratt & Whitney, CFM and Rolls Royce engines. I've never heard of this windmilling procedure! Where did you get it from?

[Speedbird48]

Aerotech,

Are you perhaps getting confused with the procedure that requires the hydraulics to be turned "on" after an engine shutdown in flight?

After you have shut down a jet engine in flight it will continue to windmill (rotate) unless it has seized. (most unlikely) Then every 30 mins the hydraulics are turned on for a short period of time to prevent the engine driven pump seizing and the fluid getting so hot that it will contaminate the rest of the system later. Also if the pump seizes it will normally shear the drive shaft.

I hope this helps.

[AeroTech]

Hi,

I've flown B737 200/400, B747 100/200/400, Pratt & Whitney, CFM and Rolls Royce engines. I've never heard of this windmilling procedure! Where did you get it from?

Regarding B 727-200, I found this procedure in the flight manual long time ago: I worked as AMT certains years (not anymore), I don't have manual now, may be 727's pilots can confirm this?
I think this procedure is used mainly during extended windmill (longer diversion time) since the trapped fuel in the engine fuel system will become hot (fuel shutoff valve is closed).
I am not saying that this procedure is valid for all aircrafts (I mentioned 2 examples 727 & 747), I am asking if this procedure is applied to other aircrafts (Boeing & Airbus).
This procedure is performed with ignition off, start levers at idle, and fuel pressure avalaible (boost pumps turned on for the failed engine).


For the B 747, the link does not provide the kind of aircraft (classics or -400) nor the type of engine (RR may be excluded since N3 is not mentioned). May be you can figure out the kind of aircraft. The procedure is perfomed if the windmilling engine is turning faster than 31% N2.
Check page 44 of the procedure in the link posted in other forum:

http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/ComAndRep/ChinaAir/APP_D.html

It will very nice and helpful if pilots can confirm (or not) the existence of this procedure in the manuals. I hope that I will get also some answers for the second part of my query posted in the first post.

Thank you.
Best regards.

[cod liver oil]

Off the top of my head,

when dry motoring B767 (JT9D-7R4 and PW4000), fuel has to be selected on to lubricate FCU/FMU.

When dry motoring A340, FADEC will take care of lubing HMU

sorry but no time to provide details

hope that helped

clo
(my first post)

[AeroTech]

Hi,

Originally posted by Speedbird48 : Are you perhaps getting confused with the procedure that requires the hydraulics to be turned "on" after an engine shutdown in flight?

After you have shutdown a jet engine in flight it will continue to windmill (rotate) unless it has seized. (most unlikely) Then every 30 mins the hydraulics are turned on for a short period of time to prevent the engine driven pump seizing and the fluid getting so hot that it will contaminate the rest of the system later. Also if the pump seizes it will normally shear the drive shaft

I don't think I am confusing the 2 procedures (fuel and hydraulic procedure). You can check the link posted above (in my previous post) for windmill procedure regarding the engine fuel system (B 747). By the way, I don't know the existence of hydraulic procedure during windmill (would you please tell me in which aircraft this procedure is applied?). I don't understand why during windmill this hydraulic procedure is applied since there is still the circulation of hydraulic (case drain hydraulic fluid) inside the pump to lubricate it, unless the hydraulic supply is shutoff (in case of engine fire) or hydraulic leakage ( total loss of hydraulic).

I hope if you (or other) can confirm the hydraulic procedure during windmill. Thanks

Best regards.

[Clarence Oveur]

You are quite right about hydraulics circulation with a windmilling engine.

The windmilling procedure of selecting fuel on for 3 min. every hour is, I believe, used by P&W.

I has been a while since I flew with the mighty JT9D, but I seem to remember just such a procedure. I haven't seen it applied by GE.

I think the manual you linked to also mentioned fuel heat, which would make it applicable to a P&W engine and not GE.

[AeroTech]

Hi,

Thank you (Clarence) for your post.

Originally posted by cod liver oil:

when dry motoring B767 (JT9D-7R4 and PW4000), fuel has to be selected on to lubricate FCU/FMU.

When dry motoring A340, FADEC will take care of lubing HMU

sorry but no time to provide details

Could you please tell me how the fuel pump and the FCU are lubricated during extended flight windmill (B767 with JT9D-7R4 or PW 4000?

How the FADEC can take care of lubing the HMU and the fuel pump on ground (dry motoring) or at flight during extended windmill?

Do you know if there is any procedure in the maintenance manual to check the fuel system (mainly the fuel pump and the FCU) after extended flight windmill (Boeing & Airbus)?

Could you please give detailed answer if you have time.

Thank you.
Best regards.

[Speedbird48]

Windmilling.

The procedure for turning the hydraulics back on for short periods was on the L-1011 the 707, Rolls and P&W engines, and probably several others.

The object being to prevent pump damage due to over heating and degradation of the fluid when it got very hot. Why screw up the hydraulic pump for a precautionary shut down and shear the drive??

I don't recall any procedure for putting the fire handle back in to circulate fuel in the FCU but then the brain has aged slightly!!

In the real "good old days" there was a procedure in the DC-7 manual when , after a runaway prop' that wouldn't feather, you pulled the fire handle (to shut off the oil supply) until the reduction gear cover "glowed", the prop' "stopped" or the prop' "departed the airplane"!! Happy days. You youngsters never had it so good but in those days we knew no different.

Speedbird48

[john_tullamarine]

If you are from Oz, Keith Hants could probably tell you a tale or two relating to missing engines ...... no idea if he frequents the sandpit as I haven't seen him in some years, now.

[AeroTech]

Hi,

Originally posted by Speedbird48

The procedure for turning the hydraulics back on for short periods was on the L-1011 the 707, Rolls and P&W engines, and probably several others.

The object being to prevent pump damage due to over heating and degradation of the fluid when it got very hot. Why screw up the hydraulic pump for a precautionary shut down and shear the drive??

I don't recall any procedure for putting the fire handle back in to circulate fuel in the FCU but then the brain has aged slightly!!

In the real "good old days" there was a procedure in the DC-7 manual when , after a runaway prop' that wouldn't feather, you pulled the fire handle (to shut off the oil supply) until the reduction gear cover "glowed", the prop' "stopped" or the prop' "departed the airplane"!! Happy days. You youngsters never had it so good but in those days we knew no different.

Thank you for your post. Unfortunately I didn't get the chance to work on these aircrafts, or even to read their manuals to see the evolution of aeronautics or aviation (which could be very useful). It seems the circulation of case drain hydraulic inside the EDP (during windmill) is an improvment for the present engines compared to old aircrafts.

I think I understand your nostalgic feeling ("good old days"), even I didn't live it. May be I will get the same feeling when I will get older, even I am not that young. My respect to all my elders (youngsters also .:p ).

Thank you.
Best regards.

[PAXboy]

Thread shift (do not want to use the word Hij@ck). Speedbird 48: or the prop' "departed the airplane"!! Happy days. That sounds a teeny bit radical. Ar you saying that the instruction was to seize the gearbox?!

If the prop felt that it was being limited in it's new lifestyle and wished to explore the rest of the universe, would it shatter? Spin off? If so, what an enormous risk of debris! Were there many examples of this?

Lastly, for the young and innocent (actually, middle aged and ignorant but let's keep moving) What is the problem with a runaway prop? Inbalance of thrust and thus pulling of the a/c line of travel?

Thanks.

[AeroTech]

Hi,

Originally posted by John_Tullamarine :

If you are from Oz, Keith Hants could probably tell you a tale or two relating to missing engines ...... no idea if he frequents the sandpit as I haven't seen him in some years, now.

I dont know if your message is sent to my attention or to Speedbird48 (So far nobody answered). I am not from Oz, I dont know its location. The town I live does not have these initials or abbreviation. But it's still good to hear the tale.

I didn't get enough information about my query, I still need the help of pilots, engineers (some are pilot & engineer), mechanics, to get mote information about windmill : it doest not take too much from your time, just take a quick look in the manual, may be you have experienced a windmill (flight or sim), or just ask your colleagues. My questions are mentioned in my first post.

Thank you.
Best regards.

[Speedbird48]

My appologies for changing the direction of a well intentioned thread but PAXboy deserves an answer. This was a form of windmilling by an uncontrollable prop".

The DC-7 had the Wright 3500 engine and a large 4 bladed prop that turned up 2900RPM for Take-Off and 2700RPM for cruise. Unfortunatly the props' had a rather nasty habit of, occaisionally, running away. By that, I mean, they would go into flat pitch, like Beta on a turbo-prop, but while in cruise!! Besides the very large amount of yaw, the ungodly noise and the dangers of structural failure as the airplane decelarated very rapidly the prop' was also liable to come off!! If that happened there was a very good chance of collecting it in the fuselage or it would take out the engine next to it as it departed. Hence the need to slow it up by fair means or foul. You had lost complete control of the prop' and it could not be feathered.

The Fire Handle was pulled to cut off the oil to the engine itself, and the reduction gearbox, which would be starved of lubrication thereby seizing it. The trick was to pull it long enough for the prop' to slow or stop without leaving the airframe and causing damage hence the wording, in the manual, that stated "Pull the Fire Handle until the Prop' slowed, the gearbox glowed or the prop' departed the airplane"!!

Thank you gentlemen, I will now seize and depart, and I am not from the fair land of Oz although I have been there many times.

Speedbird 48.

AeroTech,

To get back to your original thread I notice that you use the term \'Case Drain Fluid" in the context of it being a lubricant. This is not quite correct.

The case drain fluid is fluid that has drained from the pump case when the drive shaft seal has gone bad and is is leaking. This is normally first seen by hydraulic. or any other, fluid dripping onto the ramp after shut down from the case drain line. This line is located between the pump and the mounting flange where it is bolted to the engine and is vented to atmosphere or into the drains collector tank.

Speedbird48

[AeroTech]

Hi,

Originally posted by Speedbird48:
To get back to your original thread I notice that you use the term \'Case Drain Fluid" in the context of it being a lubricant. This is not quite correct.

I think the case drain fluid is used for lubrication and cooling. The case drain fluid circulates through the pump and then it flows to the EDP case drain filter, to the heat exchanger (where it is cooled by fuel), and finally to the reservoir. The term "case drain fluid" is used by Boeing (AMM), even the filter is called case drain filter. This is valid for the aircrafts that I know, I dont know if it is valid for the aircrafts that you mentioned before in your previous posts

Originally posted by Speedbird48:
The case drain fluid is fluid that has drained from the pump case when the drive shaft seal has gone bad and is is leaking. This is normally first seen by hydraulic. or any other, fluid dripping onto the ramp after shut down from the case drain line. This line is located between the pump and the mounting flange where it is bolted to the engine and is vented to atmosphere or into the drains collector tank.


Besides the supply line and output pressure line in the pump, there is a line called case drain line which is different than the drain line (the line that you mentioned) located in the bottom of the EDP which is used to drain hydraulic if the drive shaft seal is leaking.

Thank you.
Best regards.

[Speedbird48]

AeroTech,

You are quite correct. One of these modern "engineers" has stolen the original meaning for a Case Drain and used it for fluid that comes from the main system and is used for cooling and lubricating of the pump.

It all stems from these modern new fangled flying machines as opposed to the ancient machines of my era.

We are in fact both correct if you get the manuals out for the respective machines.

At least I found that my mind still works!!

Speedbird48.

[cod liver oil]

AeroTech,

because you wus wonderin'

Could you please tell me how the fuel pump and the FCU are lubricated during extended flight windmill (B767 with JT9D-7R4 or PW 4000?

JT9D-7R4: There is a Windmill Bypass and Shutoff Control Valve. From ATA 73-21-00, "If the condition lever is moved to the CUTOFF position fuel flow is shut off. This causes the windmill bypass and shutoff control valve to direct high pressure to close the shutoff valve. The spring end pressure of the pressure regulating valve also changes so that the valve opens to bypass additional pump flow. The reduced pressure which results prevents excessive overheating in the pump should the engine be windmilled for an extended period in shutoff".

PW4000: In the FMU, there is a windmill by-pass valve. From ATA 73-21-00, "During engine shutdown or windmilling, the MPSOV is closed and the WMBPV by-passes flow to pump interstage and maintains minimum pressure for control of engine variable geometry and valve actuators."

How the FADEC can take care of lubing the HMU and the fuel pump on ground (dry motoring) or at flight during extended windmill?

fuel pumps have to be selected 'on' when dry motoring cfm56-5a, 5b, or 5c engines. in addition, applicable c/b is pulled to open lp fuel valve. this ensures engine fuel pump and hmu are lubed during the dry spin. since mode select is in 'crank', fadec will not provide ignition (as opposed to JT9D/PW4000 where ignition breakers are pulled beforehand). sorry, i guess a blanket statement 'fadec will take care of it' leads to presumptions and i would like to retract the remark at this time he said back peddling :{

as far as extended windmilling goes, i cannot find anything in particular in airbus amm that explains how hmu lubing takes place in this scenerio.

Do you know if there is any procedure in the maintenance manual to check the fuel system (mainly the fuel pump and the FCU) after extended flight windmill (Boeing & Airbus)?

post windmilling or ifsd inspections vary from bird to bird but it seems the common denominator (provided engine exceedences have not warranted an engine change) is to determine cause of ifsd, check oil system (mag plugs & levels), and to operate engine asap or carry out engine dry out procedure.

somebody else may correct me but i find no instruction to perform specific inspections on fcu's/fmu's/mec's/hmu's or fuel pumps in any aircraft maintenance manual (post windmilling inspections). the same concern (lack there of) applies to the hydraulic pump.

hope this has helped

cod (ground op's)

[eggplantwalking]

Speedbird48
Although I didn't have a lot of time on the DC-7; however, I do remember they had the Wright R-3350 turbo compound engines (3500 CU. IN) with a rated T.O. power of 3400HP; not a Wright R-3500. Wright never manafactured a R-3500 engine. Additionally, 2700rpm was a METO power setting and not a cruise power setting. If you recall, the procedure was to set cruise rpm ( somewhere around 2100rpm depending on the weight and speed desired) and then lean the engines to peak BMEP with a subsequent drop as determined by the power chart. At 2700rpm you were not allowed to lean the engines and your fuel flow would have been unacceptable, even with the 7300 or 7800gal of fuel that could be carried. An overspeed initially caused the aircraft to accelerate and yaw away from the affected engine. The procudure was to attempt to regain governing control of the propeller with the feather button. If this failed, shut down the engine. The feather pump C/B could then be pulled for the engine and the throttle for that engine be put into reverse. While monitering the blade angle, the C/B could be closed and opened until the propeller was "reversed" into a feathered position. The procedure you describe was a "last chance" one and usually didn't work. A Northwest Airlines flight enroute to Alaska suffered a runaway that could not be corrected. The Captain reported what you described as "a cherry red engine" and the aircraft was ditched. All aboard were rescued.

[AeroTech]

Hi,

cod liver oil,

Thank you very much for your post.

Originally posted by col liver oil

fuel pumps have to be selected 'on' when dry motoring cfm56-5a, 5b, or 5c engines. in addition, applicable c/b is pulled to open lp fuel valve. this ensures engine fuel pump and hmu are lubed during the dry spin. since mode select is in 'crank', fadec will not provide ignition (as opposed to JT9D/PW4000 where ignition breakers are pulled beforehand). sorry, i guess a blanket statement 'fadec will take care of it' leads to presumptions and i would like to retract the remark at this time

I guess the procedure (CB of the lp fuel valve is pulled, fuel boost pumps ON ,etc) is applied on the ground only (as you mentioned). For FADEC engine, how the fuel pump and the HMU are lubricated during extended windmill? is it the same as JT9D/PW4000 (is the HMU fitted with bypass windmill valve)?

Thank you.
Best regards.

[Speedbird48]

Eggplantwalking,

You are quite correct. All errors are age induced and the fact that it was 04-30 probably had something to do with it??

My DC7 was a -7B and the first take-off saw #3 going crazy and the, very experienced F/E, saw 3300RPM before he hit the feather button, with little effect.

I quit and went down the street to fly DC-6's for several enjoyable years.

To go back to the original thread it appears that the newer FCU's have better cooling and lubricating systems that the older ones and I have learned something new. Or. maybe they didn't tell us too much about the earlier ones?

Thanks for the memories and my appologies to Aerotech for bending the thread.

[GotTheTshirt]

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 !!:cool:

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:D

[Bolty McBolt]

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

[AeroTech]

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]

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]

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 :confused:

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.

[Fragman88]

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





:ok:

[AeroTech]

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]

Aerotech,

PM on the way with some details:ok: