Runways disappear??

[Davejey]

Just constructed an airport using AFW;- From the cockpit, spot and tower views and from the air, I can see runways, grassed and concrete polygon areas and taxiways, but when I look
'top down view' the runways disappear.
I have kept the runways clear of everything, have flattend and excluded complete area of airport. Everything are in their own default layers. I would appreciate any help, hints, ideas.
Thanks, Davejey

[Davejey]

Solved this problem- (runways and taxiways disappeared when I used "fixed texture" in a polygon) - so experimenting .... I clicked on "invisible runway" in the polygon menu and the runway and taxiways no longer disappear!