APU Switch

[English Rebel]

Pete

I'm using APU Start from the drop down list in Buttons + Switches for a physical switch to start the APU. However when looking at the APU panel in FSX the switch goes from STOP to RUN then back to STOP. The APU ON light is illuminated but there is no amperage in the display. I can move the switch to START with my mouse and the APU starts okay. Does FSX not handle the APU start function correctly or do I need to use a different action?

Thanks

Alan

[Pete Dowson]

I'm using APU Start from the drop down list in Buttons + Switches for a physical switch to start the APU. However when looking at the APU panel in FSX the switch goes from STOP to RUN then back to STOP. The APU ON light is illuminated but there is no amperage in the display. I can move the switch to START with my mouse and the APU starts okay. Does FSX not handle the APU start function correctly or do I need to use a different action?

Sorry, I don't know. Maybe you have to keep sending APU Start until it starts, a bit like the spring-loaded prop starter (on the Magneto switches).

Is this the default FSX 737? The real APU switch has 3 positions, with the "start" position spring loaded against it. The opposite "off" position latches. I don't think I've ever used the FSX APU.

[LATER]

After checking, the "APU Starter" and "APU Off switch" assignments in FSX appear to do exctly the same. Since all FSUIPC does is send the same thing, it will obviously have the same results.

Whether the on-screen switch is used, or the FS control, the APU does actually start and stop with these controls. This you can verify by monitoring the APU RPM percentage at offset 0B54 as a FLT32. And when it is running the APU Generator switch does provide a good voltage as seen in offset 0B5C (another FLT32).

But the APU EGT dial on the default FS Overhead doesn't do anything, and the switch doesn't show the actual status of the APU either. I think the overhead in the default 737 is merely cosmetic, it does very little to show you what is going on.

Regards

Pete

[English Rebel]

Pete

I'm using the default Lear45. The strange thing is, if I keep turning the FSX panel switch on and off a few times and then turn my physical APU RUN switch to on, then the APU starts and amperage is displayed but it doesn't work every time. When this happens the FSX APU switch does in fact move from OFF to START then back to RUN (just like it does when you use your mouse to start it), as opposed to what normally happens -- going from OFF to RUN and then back to the OFF position. I thought at first that it was my switch being "out of sync" with FSX but not so. By the way, I use APU OFF for my master APU switch and when I turn the master off, then the APU does in fact shut down.

Thanks

Alan

[Pete Dowson]

I'm using the default Lear45

I get the same for that -- the APU Starter control definitely starts it according to the internal variables as supplied by Simconnect. I think it's just the local gauges which are rubbish.

then the APU starts and amperage is displayed

There's no SimConnect variable for that, so I suspect it's a local value only in the gauge, not in the actual simulation. The simulation supplies RPM and generator voltage -- the latter only after the generator is turned on of course. You shouldn't get any amps either without the generator.

Regards

Pete