Apprentice
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777/GE OIL Service

Wed Apr 24, 2013 4:17 am

Does anybody can help with reason(s) behind awful B/GE design for oil servicing in B777?
Holding servicing panel open with left arm to keep it from closing even in a no-winds condition while pouring oil little by little to avoid spillage into oil tank scupper-with-holes which swallows oil in small quantitiess is almost a nightmare. After a long 8+ hours flt, you would need 3 - 4 qts for each engine and this will take some 15 to 20 precious min from ETOPS check's allocated time.
May we expect B/GE will find the long path from easy to easy servicing like once idg manufactures did?
Was Working Toghether philosophy also aplied to oil servicing?

Thanks
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MeCe
Posts: 170
Joined: Sun Oct 04, 2009 9:19 am

RE: 777/GE OIL Service

Wed Apr 24, 2013 9:57 pm

Completely agree.

It takes quite much more time comparing cfm engines. And should be careful not to spill oil  

777 is nice plane but has some weird issues like oil servicing
 
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jetmech
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RE: 777/GE OIL Service

Thu Apr 25, 2013 1:49 am

Quoting Apprentice (Thread starter):
Quoting MeCe (Reply 1):

The worst offender in my books was A342's and A343's. After an eight hour flight, each engine would need on average 3 or 4 quarts of oil. The outboard engines were a pain because they were so high up.

I remember that the oil inlet was only just big enough to take a steady but moderate stream of oil, which we used to pour directly from the can. The spatial relationship between the oil service door and oil tank inlet however, was definitely designed with use of an oil pouring spout in mind.

I eventually worked out a set of angles and timing such that I could simultaneously get the can through the door, twist it upside down, and get it to sit on the scupper by itself whilst the oil poured into the tank. Interestingly, the following business jets have a central replenishment system for the individual engine mounted oil tanks.

http://www.smartcockpit.com/aircraft-ressources/G550-Engine_Oil.html
http://www.smartcockpit.com/aircraft-ressources/CL605-POWER_PLANT.html
http://www.smartcockpit.com/plane/BOMBARDIER/GLOBALEXPRESS-XRS.html

I don’t personally know of any commercial types with such an arrangement, though I do vaguely remember a remote oil replenishment system for #2 engine on DC-10’s / MD-11’s. On the 747, there is a centralised hydraulic fluid replenishment system in the wheel well that goes to all four hydraulic reservoirs located in the aft section of the engine struts, so making a similar system for engine oil is certainly feasible.

I suspect however, that such systems aren’t seen on commercial types, because a direct visual inspection of the oil quantity by a mechanic is the best way to ensure safety, especially for ETOPS flights. In fact, with the last company I worked for, different mechanics would check the LH and RH engine and IDG oils on ETOPS flights for this exact reason.

Regards, JetMech

[Edited 2013-04-24 19:31:29]
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
Apprentice
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Posts: 211
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RE: 777/GE OIL Service

Thu Apr 25, 2013 3:57 am

Quoting jetmech (Reply 2):

There is (was) one such commercial plane: TU-154. It has a refill conection in aft fuselage to refill at the same time 3 engines and APU. Respective checks valve would close oil flow to each engine/apu when fill out.
Agree with A340, one tech were allocated only for oil servicing and a normal flight was one in which you needed 16qts!
CFM56 scupper, last version, is the same used by GE90. Somewhere I was told it is a french SNECMA's design. I'm not sure and I have no comments..  

Brgds/ Apprentice
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MeCe
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Joined: Sun Oct 04, 2009 9:19 am

RE: 777/GE OIL Service

Thu Apr 25, 2013 5:32 pm

Quoting jetmech (Reply 2):
I suspect however, that such systems aren’t seen on commercial types, because a direct visual inspection of the oil quantity by a mechanic is the best way to ensure safety, especially for ETOPS flights




Yes you are correct, Oil quantity and condition should be visually checked. Additionally 777 AMM states oil quantity should visually verified for servicing and consumption calculation instead of eicas indication. So that It is logical not to have remote port...
 
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jetmech
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RE: 777/GE OIL Service

Fri Apr 26, 2013 2:44 am

Quoting MeCe (Reply 4):

Makes sense.

I was actually wondering why direct visual checks of the hydraulic reservoirs is never carried out, given that hydraulic oil is another fluid essential for flight. I suppose the reason is that an engine, even if new and in good condition, can be expected to consume a significant amount of oil during a flight due to the nature of how the bearing cavities are sealed and the non-perfect nature of the de-aeration process.

Hydraulics on the other hand are a sealed system, and given the pressure at which they operate at, even a very minor leak would quickly render the system useless, thus, direct physical inspection is superfluous. If the hydraulic fluid level is too low, you will know straight away as components driven off that system would fail to respond to control inputs.

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .

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