Man, the Grand Coulee Airport is a rather small airfield. Nethertheless it costed me a lot of nerves.
The runway is tangentially located along the slope of the Columbia river. Due to the elevation model this led to an irregular lateral inclination of the runway.
The aircrafts were not able to stay in place, the runway decals either disappeared in the ground or floated meters above the runway, the buildings partially plugged into the slope.
I I tried to adjust the decals to the runway, nope.
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I tried to cover the whole area with an __airport__runway ground: Didn’t look good and was not really a satisfying solution.
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I tried to fix the elevation model by converting it to a higher level: No success to eliminate the inclination.
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I even tried to modify the elevation image by painting pixels by pixels to flatten the area. The conversion result was a scenery with several horrible spikes into the air.
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Finally let’s stop these disappointing attempts: Send the bulldozers out and level the whole airfield.
This is an insignificant deviation from reality, but you’ll get a working airport.
The method was to switch off the autoheight in the TSC and set all related objects to a fixed height.
Now we have a nearly flat airport with a newly formed steep slope behind the hangars.
This is a solution I can live with. Only a road passing the steep slope is a graphic error, but I accepted that.
Phew, good job of the bulldozers.