This sim is flyable with a "Low Specs PC"

[RE77ACTION]

You could even get an extra FPS by setting your model detail to medium. It makes the 'wire frame' of the planes less complex and thus visually less smooth. But I personally find the degradation of graphics minor. I even think I like it better because model detail on high makes the planes too 'plastic' for my taste. But hey, probably lots will disagree...