Post-incident investigation needed

[downscc 1,327]

1 hour ago, Travon999 said:

During the descent I got oil temp warnings for engines 3 and 4 and had to shutdown both of them. I managed to land safely though...but at my origin airport for this last flight, my oil levels were 19.

You are not understanding the problem.  Your high oil temp is due to low fuel in those tanks and probably has nothing to do with oil levels.  Maybe you are not switching to tank to engine mode?

[TravonNicholls 1]

10 minutes ago, Captain Kevin said:

So don't fly there. Problem solved.

😂😂😂😂agreed!

 

 

 

Travon Nicholls

[TravonNicholls 1]

11 minutes ago, downscc said:

You are not understanding the problem.  Your high oil temp is due to low fuel in those tanks and probably has nothing to do with oil levels.  Maybe you are not switching to tank to engine mode?

I am switching to Tank/Engine mode though. The fuel levels weren't low.

[Qavion2 39]

Quote

You are not understanding the problem.  Your high oil temp is due to low fuel in those tanks and probably has nothing to do with oil levels.  Maybe you are not switching to tank to engine mode?

Dan, if the engines are running, I don't see how low fuel quantities would affect oil cooling. Low-ish fuel quantities are only going to affect hydraulic fluid cooling.

Cheers

JHW

[JRBarrett 3,070]

42 minutes ago, Qavion2 said:

Dan, if the engines are running, I don't see how low fuel quantities would affect oil cooling. Low-ish fuel quantities are only going to affect hydraulic fluid cooling.

Cheers

JHW

Exactly. The oil cooler is supplied by the primary engine fuel line - if THAT runs dry, the engine is going to flame out in any case.

I have never worked on the large GE/RR/PW engines used on the 747 - the largest engines I have experience with are the RR BR715 and GE CF34. But on these smaller engines, the fuel/oil cooler has a thermostatic valve to bypass the oil around the cooler when the oil is very cold, (such as when initially starting the engine on a very cold day). I assume the bigger engines use a similar bypass valve.

If the valve got stuck in the bypass position when the oil is warm, I could see how that could cause high oil temps. I don't know if the PMDG engine simulation is sufficiently detailed to have that particular failure mode though...

[Alaaar 34]

Well it seems like fun ........ :)