A bit of risk analysis is called for here.
I for one strongly believe that in the current climate of terrorism and its threat to aviation, the threat of a terrorist hijack is far more likely, than an inadvertent weapon discharge. However, non lethal weapons such as stun guns are I believe, being studied. Even so, I would openly welcome a trained sky marshal with a lethal fire arm, on to my aircraft and to any aircraft where I might be a passenger. Let’s face it, if a September 11th situation should ever arise again, a sky marshal would certainly level the playing field with the terrorist(s). With the use of special training and weapons, the chances of a terrorist gaining access to the flight deck would be virtually nil. The way that I see it is that the very worst situation that could ever happen would be that the sky marshal is killed, his weapon used on the crew, terrorists then crash aircraft into a building - Well, this would have been the same situation with the same number of people killed, had the sky marshal been on board or not.