I had luck with minor fixes at reducing CDTs since SU5, and 18.14 the sim was unplayable. With the successful minor fixes (thanks to the forum) I was able to load up and fly, but still averaging about two an hour the last couple of days. Best luck I found at the time was turning off live weather, live traffic, and multiplayer in the (general options-data tab) and limited my card to 50 fps in the nvidia control panel. That said, I was able to fly, but still getting CDTs in game and at initial load of the airport.
I did a clean install of the game, and still CDTs.
Yesterday, I reduced my graphics card by 150 hz, and I have been playing the game with all settings on, and havent had a hiccup or CDT since.
Hope this helps.