Go fly a plane into a mountain simply means kys as if you were to fly a plane into a mountain it would kill you
Go fly a plane into a mountain is used in a similar way as go play in traffic , go jump off a bridge, go drink bleach stick a fork in the electric socket, or new as of the year 2018 eat some Tide Pods sorry kids Tide Pods don't taste like candy they will just simply kill you
church hurt is where you experience a degree of distance, pain, or judgement from your church community. Essentially, you are just unable to “find your place”. This is prevalent in the Christian community, but can be extended to other religions.
Now that I am an adult I am beginning to heal from the church hurt that was inflicted on me as a child.