Welcome to the forums @x_leyter
When asking for downloads to resources, please do so sparingly - 1 thread with several requests is better than one thread per request, as this can flood other threads out of view.
Moving this into the Modelling section!
Flip the normal of the (collision) polygon that you're having problems with to solve this.
GTA camera will clip through anything that isn't facing the camera. As the camera is looking at the back-side of the normal, it's ignored by the camera.
It looks like the thread is growing a little old. If you find yourself still having this issue can you please create a new thread and elaborate on your question.
Moving this into the scripting section for you.
Unfortunately, MTA does not support custom handlings for aircraft, but changing their speed and such can be done to a certain degree through scripting.
There's a Github issue on this: https://github.com/multitheftauto/mtasa-blue/issues/2426
Hey @MRBl4Cks, we have a server manual on our wiki that helps you configure your server. If you're still looking for assistance please create a new thread in the Server Support section. The thread you're replying to is starting to show its age.