Part of the manner in which the third person omniscient style helps understand much of Brian is through the telling of both a physical and emotional frame of reference.  The narration style helps allow us to understand the harrowing conditions that Brian has to face and endure.  Yet, it also probes into the emotional depth of Brian and where he is at all points in his experience.  We understand his detached nature at the start of the novel and how it elevates into fear when the pilot suffers the heart attack.  The third person style allows us to understand how frustrated Brian felt at the tornado ruining his home, but also how difficult "The Secret" was for him to carry.  In being able to relay both the physical experience of his predicament and the emotions that accompany it, the reader develops a more whole vision of what it means to be Brian Robeson.