It might not look that stunning, but it should run. I've been gaming on a couple-generations-old MacBook a lot recently and it works surprisingly well if you're willing to drop the settings down a bit.

The main problem with flight sim on a portable is the input method though. It's challenging to fly manually without a joystick or yoke, and proper immersion really requires a throttle too. You can get something enjoyable enough going with the mouse though.