Ai passing below a Bridge impossible?

[jollyjack]

I tried to get a player plane to dive auto-piloted via a way-pointed river route to pass underneath a railway bridge, the 2 waypoints before and after the bridge set about 2m above the water surface.

How ever the plane keeps passing the Bridge at some 100 m ABOVE IT. (Tried the bridge as entity too). Has this to do with calculated ground levels?

I set the ground level for the waypoints before and after the bridge but 2meters higher. Maybe that's wrong? Some other tricks for that?

[Gambit21]

Can’t be done.

[unreasonable]

It is their ground avoidance kicking in, which over-rides waypoint settings.  I found the same thing when trying to get AI to make a very low strafing run.