I thought it was stored in the SPB file, a block of binary data. However that file doesn’t get saved while sitting on the runway with no destination. So maybe that’s the flight plan or progress data. I saved again right after take off and get a small SPB file (1kb), the ones saved with bush flights are 41kb on average for Alaska, 56kb on average for France, odd.
I tried swapping out the FLT.FSSAVE file between two saves with different weather, yet that didn’t do anything. No clue what that is for. Those files are always 8,244 bytes and mostly empty, just some unicode names.
Bush flight saves include a Weather.WPR file, yet those are presets.
It’s magic! Unless it simply doesn’t get saved (anymore).
To test that, the weather has to change first.
Anyway reloading my test file, flight plan is gone, altitude setting is gone, AP off, but the weather is still the same. Will check tomorrow what it looks like 