It's beefy enough IF ONLY IF you really know what you're doing. Having a beefy rig doesn't necessarily mean you can crank up your setting by pulling everything to the max. No, it's not.
First thing first that really kills your FPS is shadow, disable shadow if possible.
Next, scenery complexity, mesh setting, and tessellation factor, adjust accordingly. VFR flight, you may want to maximize mesh setting and autogen settings. IFR flight, you'll fly high above, don't mind about ground texture.