If you want to serve in the USAF, then that is what you put down. Every year we see a few kids from SAs and ROTC ask about transferring, changing services, cross commissioning, because they put down a service they didn't want. They went a SA because that is the one they got into or their #1 school they got an AROTC but NROTC scholarship and picked school over service. If you don't want to serve on boats, don't put USNA down. If you really don't know then apply to multiple SAs. But the goal shouldn't be a SA, its the commission in the service you want to serve in. A SA is a great path, but if you you really want to be a jet jockey, USMA isn't a great pick.