Welcome to SimV, JETZ.
Sorry to here about your sim's troubles. Does this happen with any other programs, or just FS9?
Off the top of my head, you may want to try running
Memtest. I had an issue similar to yours a good while back, and it turned out to be a faulty memory module. Whenever the sim would begin to load anything "heavy", it would crash.
Have you made any hardware changes or upgrades as of late? If so, (and actually, even if not) you might also try deleting your FS9.cfg file. After deleting it, your sim will automatically rebuild a new one. This often corrects many sudden or newly developing crashes.
There could be any number of reasons for this problem, so any further information you can provide would be helpful. For example, what are your system's specs, operating system, and so on..
There are many knowledgable people here, and even if my suggestions don't help, I'm sure someone elses will.