Judging by the look of anticipation on Flandre's face I believe that is an A-10 thunderbolt II she's in and she just discovered the GAU-8 Avenger cannon.
Lieutenant General, ma'am! *Salutes* The Okuu Squadron will escort you on your bombing run. The target is Youkai Mountain. In case of contingencies, two of your escorts will be armed with nuclear payloads. You are clear for take off! Good luck!
Looking at the text next to Flandre's arm, maybe the plane's actually an F-15? (Although not that interesting as plane looks go...How about a P-38 or a JAS-39?)
In order to see fighter planes at the closest range possible, the artist is currently studying hard to join the Japan Air Self-Defense Force. When he participated in a boot camp for new recruits called "a defense course," he was allowed to sit in the cockpit of an F-15J. He was so excited at the time that his mind went blank and all he could say was, "...!! Wow...great... This is amazing!!"
