Game use Anisotropic filtering?
 

does it use anisotropic filtering (and will it make a difference, since it is a flight sim?)

It is not at all important in CloD. I notice it in Il-2 1946 on concrete taxiways. The white paint stripes are sharper and are visible for longer distance when Aniso is increased. Such airbases are the only places where it would make a significant visible difference in a flight sim, AFAIK.

I've switched back and forth while sitting on the ground parked. I really didn't notice any difference in the scenery so just leave it off until they release a few more patches.

It bloomin' well is!

The jaggies look horrible.

Anti-aliasing deals with jaggies.

...yes....that's what I was sayying.

I have used 8xAF (forced in the driver) previously to get rid of the texture-edge lines in the sea, about 2 betas ago, but not since. To simplify its use, AF works on colour edges similarly to how AA smooth’s the edges of objects, which is particularly important in race simulators where you’re looking down a long piece of track with white lines on the edges. It has a somewhat limited benefit in flight sims though, but also doesn’t generally impact performance as much as AA.