The flight deck is where you decide what armament you’ll be carrying on the mission. You only choose a load-out for your own flight; you have no control over what the other flights take. Left-click on the arrows to cycle through the armament options. Your options are limited to the type weapons typical of the model of plane you’re flying.
If you are flying CAP or a fighter sweep, chances are good that your commanding officer will not allow you to carry bombs. The unnecessary extra weight would decrease your effective range. Extra fuel tanks also add weight, but the overall effect is an increase in range. Left-click on the Accept button take the displayed load-out and start the mission.
At this point, you are presented with your preflight checklist, which is really the Difficulty Level Menu. There are several Realism Options for flight, described below, each of which affects the way the game plays. All of these options default to the easier setting, and changing any of them raises the overall Difficulty Level. A higher Difficulty Level makes the game harder, but also increases your final score. When you are happy with the Difficulty Level, left-click on the total to signal “thumbs up” to the flight crew. When they pull the tarp, get ready to fly.