No other planes

I've put the setting on full and flown around a bit but I never see any AI planes coming into land or taking off. This is at Manchester aiport in the UK which is normally busy. When I increase the setting to max I see a lot more vehicles and planes parked at the aiport but nothing in the air or taxing.

Is this normal?

I can't say much but can take a shot at it...

may be you also require the flight plans to be installed....