Sitting around and talking with pilot friends, you hear nonstop talk about aircraft and equipment. Eventually, someone always brings up ATC in conversation. Pilots argue among themselves more intensely than Socrates debating Plato. One question that new and even veteran pilots bring up is why, when they file an IFR flight plan, that their clearance is usually never “as filed” but includes a route change of some sort.
Since I’m a working controller, they all look at me, while I briefly state a possible reason. After the assembled pilots all nod their heads and let out an “ohhh,” some will walk away still uncertain of what was explained. Overall, it is simple, there are about eight topics, within three areas, which determine whether or not you get “cleared as filed” or if ATC re-routes you before you take off.
