Moderators: richierich, ua900, PanAm_DC10, hOMSaR
seb146 wrote:I figured it was something normal. I don't recall ever seeing that but it probably is a thing on many engines. Thank you!
AA737-823 wrote:I don't see it much from the GEs and PWs I've been around. Granted, each manufacturer has their own approach to venting. But still.
AA737-823 wrote:I find it is MOST noticeable on the Rolls Royce products.
You can see it very distinctly on the A350s, and also the RR powered A380 and 787.
It was fairly common to see it on old RB211's, too, on both the 747 and 757.
I don't see it much from the GEs and PWs I've been around. Granted, each manufacturer has their own approach to venting. But still.
AA737-823 wrote:Granted, each manufacturer has their own approach to venting. But still.
fr8mech wrote:Our B744 AMM says the CF6 vents directly into the exhaust.
atav757 wrote:On the CFMs, GEs, and PWs, there’s that huge hole at the back of the exhaust and the oil is burnt off that way.
jetmech wrote:AA737-823 wrote:Granted, each manufacturer has their own approach to venting. But still.fr8mech wrote:Our B744 AMM says the CF6 vents directly into the exhaust.atav757 wrote:On the CFMs, GEs, and PWs, there’s that huge hole at the back of the exhaust and the oil is burnt off that way.
I always see quite a bit of coked up oil residue on the inside of the exhaust cones of CFM56's. This is on A340's which seem to consume quite a lot of oil so there might not be as much coking on a 737 for example.
Regards, JetMech
LH707330 wrote:I've seen this on the 340s from some of the back seat rows, that little pipe has a grayish tint on the inside. Anybody know why the CFM56-5C burns so much oil? I've heard the -7s on the 737s burn a decent amount as well.
Apprentice wrote:Continuing:: High eng oil consumption may have another reasons, like bad sealing between Gear Boxes and Agregates transmissions.
jetmech wrote:LH707330 wrote:I've seen this on the 340s from some of the back seat rows, that little pipe has a grayish tint on the inside. Anybody know why the CFM56-5C burns so much oil? I've heard the -7s on the 737s burn a decent amount as well.Apprentice wrote:Continuing:: High eng oil consumption may have another reasons, like bad sealing between Gear Boxes and Agregates transmissions.
I was told that part of the reason CFM 56's on the A340 consumed so much oil was due to the fact they worked so hard.
Regards, JetMech
LH707330 wrote:From what you saw, was it mostly a per-flight amount that they consumed, or was it per flight hour, i.e. lots of consumption at cruise as well?
jetmech wrote:LH707330 wrote:From what you saw, was it mostly a per-flight amount that they consumed, or was it per flight hour, i.e. lots of consumption at cruise as well?
I put the oil in them after a flight and 3-4 quarts was a pretty standard uplift. I have no idea when during a flight consumption was highest.
Regards, JetMech
LH707330 wrote:3-4 quarts total, or per engine?
jetmech wrote:LH707330 wrote:3-4 quarts total, or per engine?
Per engine. If an engine took a fifth or even sixth quart it was not uncommon.
Regards, Simon