Hi, I'm looking to get a good PC to be able to run FSX smoothly with some addons, will these specs be good enough; 

Processor: AMD Athlon X4 880K 4GHz (4.4GHz Overclock, 4 cores)
Graphics Card: NVIDIA GeForce GTX 1050 Ti 4GB
Memory: 16GB of DDR3 Memory running at 1600MHz
Storage: 1TB Hard Drive 
Power 500W

Thanks 

It will struggle http://valid.x86.fr/bench/e3ryel/4, but FSX is an old 2006 program so your processor is much faster than the system requirements originally set up for FSX in 2006.  It should run the default scenery/aircraft with no problems.  Add-ons with a lot of eye-candy may cause some reduction of FPS but still it should run it okay.  It's just not an i7 7700K so be careful with the sliders and stay conservative (you will still get good graphics in any case).  AVSIM has a great hardware forum where many of our hardware experts reside and they will be able to help you more.

Best regards,

Jim