In addition to the basic training requirements listed in Dogs of War, a pilot will require at a minimum: Drive and appropriate speciality; enough Academics for a bachelor's degree (at least. Higher ranking officers will require Expression and additional Academics to represent War College), and at least some survival and intimidation (resist intimidation) to represent SERE school. You are also very, very likely to be unable to take any physical or mental flaws. Combat Pilots are the top half of one percent and they know it.
For someone beyond a butterbar, you may also want to look at various skills and merits to represent leadership responsibilities of higher rank.
Edit: This is for a serving officer, or one who was released for sleeping with someone else's wife or a member of his flight team; or perhaps for an inappropriate or too visible tattoo. Someone who was discharged for a Section 8 (Mental) or Physical problem could well not meet the requirements anymore, particularly morality or flaws). Note that unless the pilot committed a felony equivalent, they are likely just 'not renewed for their slot' or otherwise given an honorable discharge. (Or a discharge that becomes honorable if they are not charged with a crime for six months after separation.