petic537

Possilbe bug - ENG OIL TEMP

Recommended Posts

I have found possible bug. Engine oil temperature jumped from 219 °C to 63 °C in a second during fuel cutoff. I think that could be a bug...

1) I activated "ENG 1 OIL TEMPERATURE" failure.

2) I got "ENG 1 OIL TEMP" warning on EICAS. Oil temp was 219 °C.

3) I moved fuel control to "CUTOFF" and in that moment oil temperature jumped from 219 °C to 63 °C in less then one second.

 

 

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Sounds unlikely, but perhaps not completely impossible (depending on what caused the problem).

What kind of engine was it? Were there any other abnormalities with the engine?
 

Share this post


Link to post
Share on other sites
6 hours ago, petic537 said:

oil temperature jumped from 219 °C to 63 °C in a second

This makes no sense to me. Shouldn't it be the reverse of what is written?

Share this post


Link to post
Share on other sites

Well you enabled a failure, who is to say the failure isn't with the sensors?  Hence, the problematic and flaky reading.  What you're seeing may actually be the clue that points to sensor failure.  Who knows?  Just throwing it out.

Mark Trainer

 

Share this post


Link to post
Share on other sites

So it's basically instantaneous (fuel flow goes to zero, temperature goes back to normal).

Some technical info: The engine EEC processes oil temperature sensor information and sends it to EICAS. Each channel in the EEC, "A" or "B", receives data from one of two oil sensors (or one of 2 sensor elements in one oil pressure sensing unit). When a fuel lever is put to cutoff, some circuits in the EEC are reset, but I don't know if the oil processing circuits are reset (I know on the real RB211, the EGT indications blank for a second or two just after the fuel cutoff levers are moved to cutoff, but I'm not sure about the oil temperature). 

OIL TEMP mesages can be caused by high oil temperature or a disagreement between the temperatures sensed by the two oil temperature sensors.

Abnormal readings can be caused by high electrical resistance. Perhaps turning off the engine caused the engine to move backwards suddenly, shaking the wiring and removing the high resistance? :tongue:

Anyway, perhaps you can submit a ticket and find out if the PMDG team intended to program it this way.

Cheers

JHW

Share this post


Link to post
Share on other sites

I see the final report is out on the Singapore Airlines (777) fire...  Not an oil temperature problem, but (initially) oil quantity problems.... 

https://www.mot.gov.sg/uploadedFiles/Ministry_of_Transport/Content_Blocks/About_MOT/Air_Transport/AAIB/CAS122 - B777-300ER Registration 9V-SWB Engine Fire 27 Jun 16 Final Report.pdf

Heavy reading.. .Strong coffee advised :laugh:

Basically, the main oil/fuel heat exchanger failed, putting fuel into the oil system. This caused the oil in the oil tank to have reduced density. The float in the tank sank to the bottom as a result, giving a low "oil" reading.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now