"Powell's question—"Is this real-world or exercise?"—is heard nearly verbatim over and over on the tapes as troops funnel onto the ops floor and are briefed about the hijacking. Powell, like almost everyone in the room, first assumes the phone call is from the simulations team on hand to send "inputs"—simulated scenarios—into play for the day's training exercise. Boston's request for fighter jets is not as prescient as it might seem. Standard hijack protocol calls for fighters to be launched—"scrambled"—merely to establish a presence in the air. The pilots are trained to trail the hijacked plane at a distance of about five miles, out of sight, following it until, presumably, it lands. If necessary, they can show themselves, flying up close to establish visual contact, and, if the situation demands, maneuver to force the plane to land. At this point, certainly, the notion of actually firing anything at a passenger jet hasn't crossed anyone's mind."