First off, you have a pretty darn good story here bud. The only critiques would be on the little things. Grammar, punctuation, and the like. Just minor things, mind!
The forest was silent, deathly silent. Trees stood all around, big trees, tall as titans and wider then a leman russ, the forest was massive and extended far further then the eye could see,. A mouse scampered away at the high pitched whine approaching from the east. The Valkyrie appeared over the horizon, black smoke trailing form it’s engines.
This is a good opening line. The first line is where you want to grab their attention. Wording is good. I'd drop the comma and do the whole "..." thing. You know: "The forest was silent....deathly silent." as opposed to the comma. Commas have a tendency to be either our friends or our greatest of enemies! When using descriptives (is that even a bloody word? LOL) make sure they flow right and don't meander too long. Don't be afraid to break up a descriptive line into more than one. A sentence that just goes on and on with commas is hard to read and has a tendency lose the reader.
Trees stood all around, big trees, tall as titans and wider then a leman russ, the forest was massive and extended far further then the eye could see,.
Trees stood all around. They were giants; tall as titans and wider than (spell correction)
a Leman Russ battle tank. (period here to keep the sentence from running on)
The forest was massive, extending further than the eye could see. (Bit of a punctuation problem here. You'll also notice that I dropped and for a comma and changed the tense of extend. This makes the sentence flow better. The word "and" is often used too much by writers ((I do it myself lol)) and is sometimes better left out in place for something else).
When you break up the sentence, not only does it read easier but it allows you to put more into it. You have the beginnings of a good grasp on descriptive but you could flesh it out a bit. When you write, picture the scene in your mind and go from there. The trees/forest for example. Don't just stop at the size. Leaf color, trunk shape/color, etc. All of these things give us the reader a clearer picture of things in our mind as we read along.
A mouse scampered away at the high pitched whine approaching from the east. The Valkyrie appeared over the horizon, black smoke trailing form it’s engines.
I like this. This is what I was talking about above. It's the little things that help make the story. However, flesh it out a little more. "The high pitched whine of approaching engines smashed the serenity that once filled the peaceful forest; the sound sending wildlife scurrying for cover, scampering away in search of safety. Thick, black smoke belched from the damaged engines of the injured Valkryrie, leaving a trail of greasy smoke as it appeared over the horizon."
“May day! May day! Valkyrie RAD-STARS-Bravo going down, some sort of engine trouble. Losing altitude, repeat RAD-STARS-Bravo is going down. Coordinates as follows: AF18374 by PK96723 repeat coordinates as fol…*static*”
Here's a point I'd like to point out (ugg...that my grasp of the english language sucks lol). Never be ashamed to keep it simple. In the mayday sentence I would have lost the long coordinates. This can be said about other things too. When someone gives longitude and latitude I start to wander. Remember, you want to keep the reader engrossed (so much so that they'll try to take the desktop to the bathroom because they can't look away). In order to do that, you need to keep the story moving. While this isn't a large point here in your story, I figured I'd mention it anyways. We don't need the serial number plastered on the bottom of the pilot's chair...just how many bolt rounds he took while flying too low over a warzone heh heh heh.
The Valkyrie suddenly lost it’s remaining engine power and crashed into the forest, crushing trees like they were egg shells. With a sickening Snap the aft wing broke off and hit a tree detonating the rocket pods anchored there. The resulting explosion flipped the Valkyrie over it skidded to a halt 5km from the place it entered the forest at.
Here is another place where going into a little more detail would be good. "The sound of angry rattling punctuated by the low thrumming of waning power were the only warnings the pilot had before engines finally gave up. With no power to keep it aloft, the Valkryie crashed into the forest, crushing trees like they were egg shells. With a sickening snap, the aft wing broke off and hit a tree; detonating the rocket pods anchored there. The resulting explosion flipped the Valkyrie end over end; sending it skidding to a halt 5km from the place it entered the forest."
A few key things you need to look for. First, once you get a piece finished, spell/grammar check it. Works has a spell/grammer check function. That would help a lot. Second, punctuation. The big thing I see is you need to sort it out. Things like "it's" when you're using it as a possessive can be sorted with grammar check. Remember, you only need an apostrophe when it's "it is". For possessives, you just use "its". Like: "The dog broke its bowl." Also, you seem to be skipping periods for some reason in some places. Those can be fixed with a good proof-reading though. The third point is proof-reading. Don't just do it once. Read it over twice, go get something to drink, hit the head; anything to give your eyes and brain a quick rest. After your break, come back and proof-read it again. You really want to do it at least three times. Sure, between spell/grammar check and proof-reading you still might miss something. That's why I advise going back over the story the next day and looking at it again. You might find tidbits here and there that need editing.
All in all, you have a very good story here bud. I shall be reading all of it this weekend when I have more time to do so
! Just look to the simple things and get them sorted out!
Good luck and good gaming,