Welcom to the Joy of Being a SL pilot sadly the only safe place to fly is protected watterways. Overland sky os Flooded with trash.
Sadly the area of sky that is clear is full of banlines if you clime up over banline hight you run into the Skyboxes. (which are easy to stear around but, you will allways find Full parsles or people who have controll issues and 0 second security orbs. (and dont give me that privacy trash it takes me 2 seconds to fly threw your tiny parsle and trust me I have no intrest in being a Peeping tom listeringe eydrops hurt)
what linden lab Needs to do is declare a No build area in the skys over the mainland 250 to 400 meters to give aircraft a Safe place in the skys