Nixa,
   The things mentioned before all apply.  If you are in a pt boat and have loaded torpedoes and rockets, you must be in the #1 position to fire your torpedoes.  To fire the rockets, you go to the #7 position, then hit  O to open the rocket launcher, then use your trigger to fire a rocket.  Use your joystick to elevate or lower the launcher for distance.  I believe a salvo of one is default for these positions, but you can change that by typing in your text  .salvo # and hit enter.  You will see your command in the text buffer after you hit enter in orange text I believe.
 Also, when you change your salvo # in planes, it will stay at that salvo # until you change it back.  Not sure if it does the same in vehicles, but I imagine it does.  If you need any help in the game and see me on "1ijac", feel free to holler at me and I would be happy to give you some help.  I fly for the Rooks.  Welcome to Aces High!    

one-eye