thankd for pics Rich and Alex.Found what I want but cant reproduce at other airports.Default London Heathrow EGLL - weather 'fogged in' ,1200 hrs summer or winter. ,3nm from touchdown(9LorR & 27L or R) - all lights are on (just visible). [Good old FS98 - one could adjust the level of Fog]JFK 31R had good strobes but no runway lights.KSFO runway 28L, similar to L/HEAStansted EGSS runway 5 - as L/HEAParis Charles de Gaulle LFPG - end lights only.other major world airports had varying degrees of lighting.Summing up - FS 9 engine has somewhere inside it, what determins when the lights are on and how much is switched on during restricted visibility.Is this the real world?I have the runway lighting program ' rwytxi.zip' by "jyarddog" but I'm still trying to work it.Dont think the lights have enough intensity for restrited visbility.David (Opa) Marshall has ,I believe, spoken of it in an earlier forum post.Hope this promotes further discussion 'cos aircraft and runway lighting seems to be one of the many topics in the forum.Clear skies,