Oh, and one more thing...if your plane gets diverted to a destination where you are required to have a license to possess the gun, and you do not have that state's license, and are forced to claim your luggage...DO NOT try to check your firearm with the airline in the morning. There have been cases in Illinois, New Jersey, and New York where people have been arrested for this.
Instead, collect your luggage, get a rental car, and drive to a neighboring state where you are 'legal' to possess the firearm. (Obviously change your airline plans accordingly.)