Tottigol - Drill for 'Eng Chip'
The real issue here is that when the engine is turned to idle not only does the load on that engine increase but more critically the generator load on the engine that you want to keep will fall dramatically and may fall as low as the 3% threshold at which point the generator is taken off line by the GMU.
This is obviously an undesirable situation if you then shut down the engine with the chip as you will then have no gennies. It took 3 years of detective work to find that little gem and yes we checked it in the real aircraft and that's exactly what happens. Quite how two electrical systems that are supposed to be isolated can behave in that way I am not sure and I have yet to find an explanation but I'll keep trying. The trick with the Bus Tie neatly circumvents this problem but the RFM leaves you in the dark as to why you need to use it.
Not all the sims behave as they should so you can't use your FSTD to verify that this point. Check it next time you shut down on the real aircraft.
G.
PS. Now back in harness at Sesto