Questions concerning engine maintenance
Thread Starter
Joined: Jun 2005
Posts: 182
Likes: 2
From: USA
Questions concerning engine maintenance
Hi,
This is my first post. I have some questions related to the maintenance after certain abnormal flight conditions:
1-What's the maintenance procedure regarding the engine oil system, after in flight engine shutdown and extended windmill [mainly for quadjet, trijet or ETOPS (twin)]?
-What's the maintenance procedure regarding lubrication system after oil loss?
-Are engines limited (in time) for the windmill because of the low oil pressure?
-Is oil viscosity a problem for engine lubrication after extended windmill (oil may get cold soaked after this long period of windmill)?
-What's the maintenance procedure regarding the oil system during in flight engine fire.
2-What's the maintenance procedure regarding the fuel system after extended windmill (engine shutdown, not engine fire)? since the fuel is shutoff, and the fuel fuel pump and the fuel metering valve (FCU, MEC, HMU) are not lubricated by fuel during extended windmill (at the opposite the maintenance manual recommends to lubricate these 2 components during short time of the ground dry motoring by opening the fuel spar valve, fuel boost pump ON, etc...)
-Are the engines limited (in time) because of the fuel is shutoff after extended windmill? since the the fuel pump and the the fuel metering valve are not lubricated.
Thank you for your answers.
Best regards.
This is my first post. I have some questions related to the maintenance after certain abnormal flight conditions:
1-What's the maintenance procedure regarding the engine oil system, after in flight engine shutdown and extended windmill [mainly for quadjet, trijet or ETOPS (twin)]?
-What's the maintenance procedure regarding lubrication system after oil loss?
-Are engines limited (in time) for the windmill because of the low oil pressure?
-Is oil viscosity a problem for engine lubrication after extended windmill (oil may get cold soaked after this long period of windmill)?
-What's the maintenance procedure regarding the oil system during in flight engine fire.
2-What's the maintenance procedure regarding the fuel system after extended windmill (engine shutdown, not engine fire)? since the fuel is shutoff, and the fuel fuel pump and the fuel metering valve (FCU, MEC, HMU) are not lubricated by fuel during extended windmill (at the opposite the maintenance manual recommends to lubricate these 2 components during short time of the ground dry motoring by opening the fuel spar valve, fuel boost pump ON, etc...)
-Are the engines limited (in time) because of the fuel is shutoff after extended windmill? since the the fuel pump and the the fuel metering valve are not lubricated.
Thank you for your answers.
Best regards.
Joined: Dec 1998
Posts: 3,038
Likes: 52
From: .
From the 744 with RB211 MM
Procedure for windmilling
SUBTASK 71-00-00-716-038-D00
(1)
If the engine turned for less than 30 minutes with or without oil pressure, examine the engine as follows:
(a)
Do a check of the engine oil level (PAGEBLOCK 12-13-03/301 Config 1).
(b)
If the level is low, dry motor the engine for 30 seconds (PAGEBLOCK 71-00-00/201).
(c)
Do a check of the engine oil level and fill if it is necessary (PAGEBLOCK 12-13-03/301 Config 1).
SUBTASK 71-00-00-206-009-D00
(2)
If the engine turned for more than 30 minutes without a total decrease in oil pressure, examine the engine as follows:
(a)
Examine the magnetic chip detectors (PAGEBLOCK 79-00-00/601).
(b)
Dry motor the engine for 30 seconds (PAGEBLOCK 71-00-00/201).
(c)
Do a check of the engine oil level and fill if it is necessary (PAGEBLOCK 12-13-03/301 Config 1).
SUBTASK 71-00-00-206-010-D00
(3)
If the engine turned for more than 30 minutes with a total decrease of oil pressure, examine the engine as follows:
(a)
Examine the magnetic chip detectors (PAGEBLOCK 79-00-00/601).
(b)
Dry motor the engine for 30 seconds (PAGEBLOCK 71-00-00/201).
(c)
Examine the magnetic chip detectors (PAGEBLOCK 79-00-00/601).
(d)
Do a check of the engine oil level and fill if it is necessary (PAGEBLOCK 12-13-03/301 Config 1).
(e)
Start the engine and operate at ground idle for 5 minutes (PAGEBLOCK 71-00-00/201).
(f)
Examine the magnetic chip detectors (PAGEBLOCK 79-00-00/601).
(g)
If the engine is satisfactory, continue it in operation.
(h)
Examine the magnetic chip detectors after the subsequent flight or in less than 10 hours.
(i)
Inspect the starter magnetic chip detector (PAGEBLOCK 80-11-01/601) and change the starter oil (PAGEBLOCK 12-22-02/301).
Procedure for windmilling
SUBTASK 71-00-00-716-038-D00
(1)
If the engine turned for less than 30 minutes with or without oil pressure, examine the engine as follows:
(a)
Do a check of the engine oil level (PAGEBLOCK 12-13-03/301 Config 1).
(b)
If the level is low, dry motor the engine for 30 seconds (PAGEBLOCK 71-00-00/201).
(c)
Do a check of the engine oil level and fill if it is necessary (PAGEBLOCK 12-13-03/301 Config 1).
SUBTASK 71-00-00-206-009-D00
(2)
If the engine turned for more than 30 minutes without a total decrease in oil pressure, examine the engine as follows:
(a)
Examine the magnetic chip detectors (PAGEBLOCK 79-00-00/601).
(b)
Dry motor the engine for 30 seconds (PAGEBLOCK 71-00-00/201).
(c)
Do a check of the engine oil level and fill if it is necessary (PAGEBLOCK 12-13-03/301 Config 1).
SUBTASK 71-00-00-206-010-D00
(3)
If the engine turned for more than 30 minutes with a total decrease of oil pressure, examine the engine as follows:
(a)
Examine the magnetic chip detectors (PAGEBLOCK 79-00-00/601).
(b)
Dry motor the engine for 30 seconds (PAGEBLOCK 71-00-00/201).
(c)
Examine the magnetic chip detectors (PAGEBLOCK 79-00-00/601).
(d)
Do a check of the engine oil level and fill if it is necessary (PAGEBLOCK 12-13-03/301 Config 1).
(e)
Start the engine and operate at ground idle for 5 minutes (PAGEBLOCK 71-00-00/201).
(f)
Examine the magnetic chip detectors (PAGEBLOCK 79-00-00/601).
(g)
If the engine is satisfactory, continue it in operation.
(h)
Examine the magnetic chip detectors after the subsequent flight or in less than 10 hours.
(i)
Inspect the starter magnetic chip detector (PAGEBLOCK 80-11-01/601) and change the starter oil (PAGEBLOCK 12-22-02/301).
Joined: Feb 2005
Posts: 4,581
Likes: 0
From: flyover country USA
Although your question is general, the answers will certainly be specific to the engine type because of design differences. The MM quotes by spannersatcx are good practice in any event, but check the MM for your specific aircraft/engine model.
For example -
Most fuel system designs I am familiar with ARE fully lubricated (by recirculating trapped fuel) during windmilling, and thus have no time limitations in windmilling. Once again, your mileage may vary.
For example -
-Are the engines limited (in time) because of the fuel is shutoff after extended windmill? since the the fuel pump and the the fuel metering valve are not lubricated.
Thread Starter
Joined: Jun 2005
Posts: 182
Likes: 2
From: USA
Hi all,
First I thank Spannersatcx and Barit1 for their posts.
Orginally posted by Barit1
Although your question is general, the answers will certainly be specific to the engine type because of design differences. The MM quotes by spannersatcx are good practice in any event, but check the MM for your specific aircraft/engine model.
My question is not specified to a certain kind of engine, it could be :GE, RR, and P&W engines installed in Boeing or Airbus aircrafts. I don't have AMM, I am studying now (making kind of reseach for my study, I worked as AMT before (not anymore). You will not find these technical information in school or libraries (No AMM, CMM, or AFM,..)
The MM of the RB211 (B744) don't mention the problem of of the lubrication of the fuel pump and the fuel metering valve (FCU, MEC, or HMU. I don't know why: is it because there is a windmill procedure that must be applied in flight in case of windmill for 3 minutes at one hours intervals if shutdown engine is windmilling faster than 31% N2? (this procedure consist move the start lever to idle, with fuel pressure available and engine ignition off). I get this information from a post (from operations manual) of someone from another forum but the flight manual don't mention the kind of engine nor of aircraft (just mention 747 aircraft
without the dash number: 100, 200,......or 400.
If the engine fuel components are lubricated by recirculating the trapped fuel (as mentioned by Barit1), the fuel may become hot (not cooled) after a certain short time, because the fuel is not renewed. I think (just a guess) that's why the fuel must be dumped during windmill (B727 each 30 minutes during 30 secondes I think, B747 3 minutes each hour windmill). I don't know about other aircrafts, I hope if someone can check in flight operations manual for this kind of windmill procedure (As I said I don't have manuals). I also read in other forum that the engine (I think CFM56) in A 340 is limited to 8 to 10 hours of windmill. I don't know why: is it because of the low oil pressure or the poor lubrication of engine fuel components during extended windmill?
Thank for your help and answers in advance.
Best regards.
First I thank Spannersatcx and Barit1 for their posts.
Orginally posted by Barit1
Although your question is general, the answers will certainly be specific to the engine type because of design differences. The MM quotes by spannersatcx are good practice in any event, but check the MM for your specific aircraft/engine model.
My question is not specified to a certain kind of engine, it could be :GE, RR, and P&W engines installed in Boeing or Airbus aircrafts. I don't have AMM, I am studying now (making kind of reseach for my study, I worked as AMT before (not anymore). You will not find these technical information in school or libraries (No AMM, CMM, or AFM,..)
The MM of the RB211 (B744) don't mention the problem of of the lubrication of the fuel pump and the fuel metering valve (FCU, MEC, or HMU. I don't know why: is it because there is a windmill procedure that must be applied in flight in case of windmill for 3 minutes at one hours intervals if shutdown engine is windmilling faster than 31% N2? (this procedure consist move the start lever to idle, with fuel pressure available and engine ignition off). I get this information from a post (from operations manual) of someone from another forum but the flight manual don't mention the kind of engine nor of aircraft (just mention 747 aircraft
without the dash number: 100, 200,......or 400.
If the engine fuel components are lubricated by recirculating the trapped fuel (as mentioned by Barit1), the fuel may become hot (not cooled) after a certain short time, because the fuel is not renewed. I think (just a guess) that's why the fuel must be dumped during windmill (B727 each 30 minutes during 30 secondes I think, B747 3 minutes each hour windmill). I don't know about other aircrafts, I hope if someone can check in flight operations manual for this kind of windmill procedure (As I said I don't have manuals). I also read in other forum that the engine (I think CFM56) in A 340 is limited to 8 to 10 hours of windmill. I don't know why: is it because of the low oil pressure or the poor lubrication of engine fuel components during extended windmill?
Thank for your help and answers in advance.
Best regards.
Orginally posted by Barit1
