Back in the late 1990's/early 2000's, my office was across the street from Boeing Field in Seattle. It also directly under the flight path for SeaTac airport. Now, it was far enough from SeaTac that the aircraft were usually high enough as to not be too noisy or bothersome, but there were exceptions. The most notable exception was a Northwest 747 headed for Japan - when takeoff's were to the north, it would go over so low and so loud that it rattled the windows. I don't remember now if it was a daily or just several times per week - but I do remember it went over right about 2pm. Before long I just stopped looking out the window to see what was going on - if it suddenly got noisy and it was about 2pm, I knew it was Northwest...