>> i want to go back to our panel, bring in mary schiavo, former inspector general for the department of transportation, david gallo of the woods hull ocean graphic institution and cnn aviation analyst les abend. les a fire on board, how serious is that, as a pilot how big a concern is that for you and do you do? >> it's got to be the worst scenario on an airplane. >> really? >> yeah. because you have no control over the situation for the most part except to be able to attempt to extinguish the fire. if it happened in the forward cargo department like seemed to be simulated there, you would start a whole process of arming bottles, freon bottles and deploying those bottles into the cargo compartments. you would select which one, assuming the forward. >> that's done electronically? >> it's done electronically through switches. but you would manually have to go through that process to do it. there's a couple of freon bottles. starting the process shuts down fans all sorts of things so it