Help with terrain

Am currently modifying WBMU(Mulu) for P3DV4. The stock bgl is giving airport elevation of 1200feet which is not accurate in real life. I have adjust the elevation to 87.68feet as per charts. I drew the polygon over the terminal etc and flatten mask class map and exclude autogen. It seems to work however i have an odd looking triangle terrain which is obstructing any approach now. I might be doing it wrong would appreciate if any of you guys could give input.


View attachment 50138
Could you show an image of this? The attachment isn't working.

It's probably because you need to merge the airport's terrain poly with the surrounding polygons. You can make a series of polygons adjusting each vertex's height to that of the surrounding scenery.

In ADE you can right click "Move aircraft to this point" and the "set elevation to aircrafts" on the vertex
Hello I have found a building msitaker myself : I havn't bult first the flattern polypon ! The mistake didn't comes , when I have build it first an then on it the airport.
greetings from GER