A prime example of this is at night. In the midwest United States, one can be at 41,000 ft over Springfield, MO and be able to see the lights of St. Louis, Kansas City, Tulsa, Oklahoma City, Wichita and maybe even Omaha and Memphis. Easily 100+ miles away. A house fire will stick out like a sore thumb a looooong way away.

You sure about all that? OKC is nearly 300 miles away from Springfield, I think your estimates are perhaps a bit generous.

In FSX we all know we can limit or visibility to simulate real life fog and haze.But, how is it really in real life, when at high flightlevels, what is a "usual" maximum visibility when having clear weater? Can it get up to 200miles?I'm locking mine at 100miles and clouds at 110miles, which gives me nice clouds coverage for the visible area, or so I believe :( What do you use and what is IRL?

Hi Word Not Allowed,Back "in the day" before we had METARs here in the U.S. (called a “Surface Aviation Observation” then) visibility was reported in distances greater than 10sm. In Indiana, normally (from what I remember) max reported visibility would not exceed 20sm. We had a discussion one day about reported visibility during one of my classes at Purdue (University) and I can remember the prof. saying how mountain peaks were used "out West" in Colorado etc. to determine what the visibility was. So it was not uncommon to see an observer from a certain airport (before all this stuff became automated and max reported visibility now is 10sm) report surface visibility as high as 90sm because the observer could see "such and such" peak.I have my ASE max surf. vis at 100 and max upper vis. at 200sm (which I think consistent from my RW experience) w/ FSX cloud draw to 110mi. How these settings play out in FSX compared to RW… I can’t say for sure as I do not currently fly RW. On a recent flight at 30,000ft from WABB (in Biak, Indonesia) to RPMD (Davao City, Philippines) I could see the tips of some peaks to the SW above a cloud layer… without knowing my exact position (a flight using just dead reckoning and NDBs) and the exact geography I had no idea what peaks I was looking at (could barely see btw)… but the “view” seemed reasonable enough.Hope that helps.