Passengers should be armed IF certain criteria are met. They have to pass the FBI background check required to obtain a CHL. They have to train and have a minimum of 100 hours advanced range training with a minimum score of 90 percent. Then they will obtain an upgraded CHL that allows them to be armed while flying. They will dress in a manner that conceals their weapon at all times. They will not advise any passengers they are armed. IOW, they will be like the literally millions of people you come in contact with on a daily basis, armed without your having any clue. Perhaps if bad guys knew at any given moment there are many many many thousands of additional individuals trained and capable of eliminating them flying anywhere and everywhere, perhaps more than one on any given flight, they would decide to not fly.