Yes, like flieger, I've seen the same exact thing happen. The academy understands that no one is perfect. If you have your appointment and you drop down 1 letter grade in a class, no big deal; I.e. Had an "A" in Chemistry the first semester and dropped to a "B" the 2nd semester. They don't even mind if it happened to 2 classes. They understand grades and classes are fluid. However, fail a class, and you can pretty much kiss your appointment good by, (That's what happened to one of our state applicants). Figured everything was set, had his appointment, decided that the rest of his senior year wasn't that important, skipped a certain class pretty much the rest of the year. Teacher failed him and he lost his appointment.
I believe that the main point in the academy's eye, isn't that your GPA dropped. Their opinion is; you couldn't have gotten an appointment in the first place with any low gpa to start with. To go 4 years with excellent grades; e.g. >=3.85 gpa; and then fail a class; shows more about your "WORK ETHIC" than it does your academics. That's why they lose their appointment.
Also, on a side note: This past graduating year; a fellow athlete in my son's graduating class. Broke more state records that can be counted for track. Was offered more scholarships than you can count. We're talking the biggest schools in the country. He let his senior year pretty much slip academically because he already had his future lined up. Well, because of his crappy grades his senior year, his overall GPA dropped to a 1.95. Once it went below a 2.0, NCAA rules start kicking in and colleges get nervous. Long story short. EVERY SINGLE COLLEGE retracted ALL OF THE SCHOLARSHIP offers. Some said if he went to a Comm College and raised his grades, he could check back with them. He graduated high school with NO OFFERS at all; no money to pay for college; and his entire motivation and moral destroyed. He didn't even have the ambition to try for summer school to raise it. He is now NOT IN COLLEGE at all, and is working part time for a lawn service/tree trimming company.
So, take it for what it's worth. If you bust you butt for 4+ years; get good enough grades and such to be considered for the academy; have a good enough all around record to receive a nomination and an appointment; then you should have no problem being the type of person who can maintain the grades to keep the appointment. Don't worry that you didn't get to hold your 4.0gpa because you got a "B" in the 2nd semester. However, if you "FAIL" a class, sorry to say, but you "Probably" deserve to lose your appointment. I say "Probably" because there could be extenuating circumstances like a death in the immediate family that forced you to change schools mid year; a major medical illness or injury, or something similar. In those cases, you need to talk to your ALO and academy counselor to ensure they are aware of what happened. But for anything else, how you finish up your senior year is a direct reflection of your "Work Ethics". later... mike.....