Gentlemen:


Captain Sim wrote on Apr 13^th, 2020 at 4:15pm:

What/when exactly we should change in the code? Thanks.

I guess it depends on what you want it to do.  If your focus is solely on normal operations (no abnormals or emergency procedures) you could probably hard-code the temps to rise from ambient temps at engine start to stabilize 125* to 145* and just stay there until engine shutdown.  Number are an estimate -- I'll pay more attention to trends on my next rotation but, the global airline situation being what it is, that may be some time in the future yet.

Regarding abnormals or emergencies, you may still be able to get away with a hard coded trend.  In 12 years of flying these engines (PW, that is) I have never had a high oil temp issue.  Waiting to advance the power until the temp rises out of the yellow is normal in winter; waiting for takeoff power until 50*c is also normal; but no high temp issues.  It is such an unlikely occurrence that there isn't even an EICAS message for oil temperature, only X ENG OIL PRESS for pressure.

Regarding the oil temperature reading -- the system takes the readout (as I understand it) on the return line from the engine to the reservoir.  This is on the opposite "side" of the system from the fuel/oil heat exchanger.  Thus, any variance you would want to program into the oil temp would be most directly related to engine power and engine power alone.  That said, running the engine at full rated power for 5 minutes should not be enough to cause an oil overtemp...

Hope this helps.  As I am not a programmer, I'm not really sure how to help translate RW behavior into code. 

Cheers,

Jason