I checked out your story. Overall it was quiyr good. One minor change I'd suggest is starting off with the drop off. Jump right into the airplane suddenly coming under heavy fire--bullets tearing through the cabin, some guy's head turning into red mist, the sudden sensation of falling then the strange, easy calm of free fall as the narrator parachutes to the drop zone.
Other than that, I'd recommend researching military jargon, and having the characters throw around some authentic acronymns. (The US Army seems to have an acronymn for just about everything.) Don't go so heavy as to lose readers who aren't familiar with those terms, but I think dropping a few in would be good for the story.
Nice work. Good luck!
