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.
Orginally posted by Barit1