Here’s something odd:
I noticed that my last crash whilst flying, happened at exactly one hour into a flight. Today I loaded up the sim and just left it running in the desktop (windowed) on the main menu page. At exactly 1 hour, it crashed. That’s without me touching anything, I just left the PC sitting in the background with the menu running, doing other things with the flight sim music in the background. I noticed the music fell silent, noted the clock, exactly 1 hour had passed since I started the sim.
So why on earth would the sim just close at an hour???