In mountainous areas of you fly solo and select final you spawn inside a mountai and crash on exit. Also when you stop the engine on the super decathlon the prop disappears.
This is a known issue and the developers are aware of this.
As for the spawning on final issue, I think its known as well, but I’m not entirely sure. Will look a little further.
EDIT: The spawning issue is also known. I’m not sure how detailed I can go into in regards to the issue, but just wanted to let you know that its known.