In Hatchet, what does Brian think about in the plane？How does he feel about this topic and why？

In the book Hatchet, thirteen-year old Brian Robeson is the only passenger on a tiny plane bound for the northern woods of Canada. At first, he thinks it’s interesting to be flying in the small plane, and stares at the control panel in wonder. The pilot gives him a great opportunity by letting him have control of the plane.  
Soon, however, Brian’s thoughts turn to his parents, who are getting a divorce. He feels very angry at the lawyers, and pretty much at everybody, for trying to tell him how he’s supposed to feel and how the divorce will affect his life. Brian begins to think about something that he refers to as “the secret,” though we have no idea at this point what it is.
While thinking about these things, Brian feels as though he’s going to cry, but he attempts to hold his tears back. He’s ashamed and nervous about his feelings, and doesn’t want the pilot to see him crying. The thoughts of the divorce lead to thoughts of his parents, who are not in agreement about the whole thing, leading us to believe that Brian feels torn between them and split in two.
His father has no idea why his mother wants the divorce and is torn up about it, while his mother wants to comfort him. We learn that she’s unaware that Brian knows “the secret,” but we feel that it might have something to do with the divorce. There is a sense that Brian feels like he must protect both of his parents from the secret and the fact that he knows it. For a thirteen-year old boy, he is under an immense amount of pressure.