http://www.simviation.com/fsxmisc1.htm Download number 3 from the top.
This file gets placed into your FSX folder. Flights/Other and the you replace the .FLT
There is a detailed Readme folder in the download.
Basically what this does is, when you load ANY aircraft in Free flight the craft will start with ALL systems down. You start at the battery and work your way through startup.
Nice this is it does not apply to missions meaning you wont drop out of the sky when you load a mission where the craft is in the air.
Nice feature, hope it is what you are looking for