Apparently I'm crashing in the offline mode as well. Had this problem a short while back also since the last patch.
Been a while between flying for me.
Is this a case of me needing to totally reinstall AH?
Is there an easy way to do this?
Do I need to completely delete the files first?
Any help is appreciated
A complete re-install wouldn't hurt. It would get you back to a clean install....if done right

Goto start/programs/accessories/windows explorer. When that opens navigate to the aces high folder, and save the "settings" folder to your desktop ( this is so you can drop it back in and all of your head positions and stick settings are the same).
Close out those windows and goto start/settings/control panel and click on "add and remove software". Once the screen populates, use it to Remove Aces High. After it is uninstalled, be sure the desktop icon was removed(if not just drop it in the recycle bin). Download the latest version of the game and install it.
Once installed, the game will try to set its self to your computer. Try it with ut making any changes. This is where the Dxdiag report can come in handy. Many here can look at it and let you know the best setting to set your game to for optimum play.
Good Luck