I have found that no matter what altitude I fly under most bridges including the GG in San Fran, a weird thing happens just as I fly under at 80 ft alt.
The plane gear extends.
A kind of visual “slap the water” thing happens, the plane bounces down to 20 ft alt.
Surely this is a bug. The SAME glitch occurs if I strike the objects intentionally.
What I suspect is that although bridges are rendered as if they are 3D objects, they exist only as height maps within the MSFS model, and so the sim has been programmed to hack around the faked world model.
I wonder if this is a bridge thing liked you mentioned. I noticed today during the Denmark bush trip that the Great Belt Bridge roadway appears just under the water, so it looks like the cars are driving submerged from 2000ft.
I think it’s a problem with the collision detection system which only has one object you can collide with which is the current terrain and “decor” height. The thing is though I flew right through that building in Shanghai, which had a circular hole in the building.
Yes it’s bad modelling. Lots of bridges did this, until recently. We even set up a special topic, to report bridges that allow flying under. Most bridges got repaired with the SU-5… but not everything… London Tower Bridge won’t allow it either.
NOTE: just tested it with ICON… it has issues indeed. When you approach, you see the shadow of the “wand” in the water…