I don't think that it can hurt to send an email telling Admissions that he recently earned his private pilots license. It may give a small boost to the Application. For what its worth, I view the pilots license as a demonstration of maturity, goal setting and achievement rather than some special skill. The Navy doesn't really care if someone can fly an airplane going into USNA ---in fact, some flight instructors view it as an obstacle because you may may have to unlearn bad habits and learn the Navy way. I earned my pilot's license in High School, and do believe it helped me a little in my early NFO training, as I was already acclimated and comfortable in the air, and could concentrate on navigation and other tasks rather than the wow factor of flying.