Couple Quirky Panel Issues

[Guest jase439]

1. The L ENG OIL PRES and R ENG OIL PRES lights seem to get into a state where they become "stuck ON" regardless of Oil Temperature or Pressure.2. More questionable is that these gauges seem to have nothing to do with Oil Pressure at all. Low Oil Pressure will not trigger their illumination, but low Oil Temperature will (< 30C).3. Periodically the A/T DISC annunciator will come on and remain on regardless of A/T switch position. The EICAS warning will go off and on in synchronisity with the A/T switch, but the red annunciator stays on (and consequently the Master Caution light is permanently illuminated as well). I seem to be having this problem after restarting the aircraft for a second or third time (usually in a layover scenario) - almost always after having previously landed the aircraft in which I disconnected the autopilot and A/T on final approach.Anyway, these are minor annoyances. If I unload and reload the panel, both problems (#1 and #3) go away.I've been surfing through old posts on a couple of these, but didn't come up with anything conclusive. Has anything been learned on these items or do they simply remain "known anomalies"?J

[Guest Ian_Riddell]

>>1. The L ENG OIL PRES and R ENG OIL PRES lights seem to get >into a state where they become "stuck ON" regardless of Oil >Temperature or Pressure. >>2. More questionable is that these gauges seem to have >nothing to do with Oil Pressure at all. Hi Jase.I had a quick look at my training notes and came up with some interesting facts which may help with the diagnosis of this problem."L ENG OIL PRES" and "R ENG OIL PRES" messages are generated by an oil pressure switch on each engine. The switches open at 15psi (px ok)and close at 10 psi (low px). The level of EICAS warning is dependent on whether the aircraft is certified under FAA or CAA rules.Pressure "indications" on the other hand are provided by completely independent pressure sensor-transmitters. The lower red line limit for oil pressure is set at 10psi. However the yellow upper band limit varies between 13 and 34 psi depending on N2 speed (60% to 110%). If PIC is modelled to this complexity, I'm wondering if your observations allowing for switch hysteresis and these programmed indication variations?>Low Oil Pressure >will not trigger their illumination, but low Oil Temperature >will (< 30C).No doubt oil temperature will influence pressure in the real world, but to what extent, I can't say (I'll have to leave this to the experts ;-)).Hope this helps.Cheers.Ian.

[Guest jase439]

Hi Ian,The logic in PIC does not appear to be this sophisticated (at least with regard to the OIL PRES annunciators above the autobrake). The "yellow zone" on the Oil Temperature readout is pegged at 30C and the OIL PRES annunciators will illuminate whenever the temperature falls into this region regardless of oil pressure.To prove this point, I adjusted the Temperature scalar in the AIR file so that the oil temperature would never drop below 30C (above the Oil Temp's yellow zone). The OIL PRES annunciators never illuminated - even at 0 PSI and 0% N2.My guess is that the OIL PRES logic is simply polling an internally calculated variable calculated by FS (which may or may not include the logic you describe) - only the wrong variable (temperature instead of pressure) seems to be queried here.J