Is it possible to have the FMS powered ON without the use of GND PWR or engines running with generators switched ON?Reason I ask is normally I would setup the FMS before pushing back from the gate and I would start my engines after pushing back. Currently this doesn't seem to be possible as far as I can tell because when I disconnect the GPU prior to pushback the FMS shuts itself OFF and I will then not be able to switch it back ON before I've started at least one engine/generator or reconnected the GPU. And regardless I will have to re-program the FMS since it "forgets" everything when it shuts itself OFF.I wonder how this is done IRL?TIA for any input or tips!

Sorry but just realized I forgot to tell you in my post above that the question if related to the J41...forgot the forum is a general PROP forum :(

Well it's a little annoying but You can't do it other way, You can try push back with GPU connected but it looks silly. I got used to it, theres not that much data to enter, simply start first engine, turn on generator, start second engine and while second engine is starting enter that data to FMS, that's how I do this. I hope it will be fixed in SP2.

A little bit off topic:J41 usually don't push back, since they do not use jet bridges. Normally they are parked on remote stands, where push back is not necessary. If you really need to roll backwards you would just power back. If I remember correctly, moving the aircraft without power to the avionics after inital alignment is forbidden, because it would damage the gyros. They need 15 minutes to spin down completely.

Thanks for your input guys, I'll find a way to work around this.

I could be wrong, but thought there was another post a week or so ago that showed how to shut the avionics off, perform the engine starts and still maintain the FMC data?

OK, maybe there already is a way around this then.For now I decided to solve this "problem" by starting one engine up before p/b on those occations when I'm parked at a stand but like someone else said above more realistic for these kind of a/c of course is to be parked at a location where p/b isn't needed in the first place.