great Story, But..
American officers don't re-up, nor do they have contracts. If they are not on Active Duty nor in the Reserves or National Guard, they are still subject to be recalled to active duty during a declared war. Many old officers and NCO's would probably be volunteering to take over recruiting duty or serve in some administrative position to free up Soldiers, Marines, Air Force, and Navy ratings to fill combat or military support positions.
American military use the NATO phonetic system to identify (Alpha, Bravo, etc.) L is not pronounced ell, but Lima. If an artillery battery is split into separate positions, each gun must be initially given firing information. If firing on a grid location, the grid is identified by eight places (ie, 3249 2796).
As a civilian pilot, the term "flat spin" scares the pıss out of me. A "flat spin" is nearly uncontrollable unless you are at a high enough altitude to do some tricky maneuvering. The idea that a flat spin is controllable to stop at 180° to your original heading is mind-blowing. But if you have a VTOL aircraft, some sort of mass changing or anti-gravity capability and nearly unlimited power - I guess it's just science fiction.
There are some homofone issues and what looks like spell-check errors, but those could be eliminated by a good beta-readers team.
I hope there's a third book (or novella) to connect this to the Odyssey series.