Note that this list is not comprehensive. I picked out a few examples of each kind of error or problem I found. Of course, not everything is a black-and-white issue; this is not a list of things you have
to fix, but take each under advisement.
I'm going to do something to illustrate a point. Here are the first words of all your narrative sentences for the first scene:
a, the, the, I, I, pneumatic, the, the, an, a, a, the, she, I, I, below, a, a, I, a, I, Zephyr, I, she, I
Except for that one "below," you have very repetitive sentence beginnings. Now, some words like "a" and "the" are so mundane that they pass by without notice, so it's not so much that the words themselves are repetitive; it's more that the sentence structures are. They all start with the subject. It gets to feel like a list of actions and doesn't flow very well.
>I swallowed and met her eyes. “Which means… we have to land.” Zephyr nodded. “Crap.”//
It's a little ambiguous who says this dialogue.
>left, a broad river valley at the north end, and an immense forest along the left//
It's a little odd that you're mixing types of directions.
You're probably giving more of a description of the map than you need. How many of these details are actually going to be important to the story? If a lot of them, then how many will be important soon? It's better to introduce information as it's needed instead of pushing a bunch of it at once and hoping the reader will remember it later.