Back when I was a student pilot, I developed a habit during the preflight inspection of stepping back and pausing to get an overall visual impression of the control surfaces on the airplane. It started after I had noticed that one of the ailerons on a Cherokee I was about to take out for a solo flight didn’t look quite right. From a distance, it was easy to see that while the aileron on one side was in alignment, the other aileron was sagging significantly.
My little habit was vindicated recently when the National Transportation Safety Board added its considerable weight to the notion that DC-8 flight crews need to get a good visual impression of elevator control surface positions during walkaround inspections. This was an outgrowth of its investigation into the February 16, 2000, crash of a four-engine DC-8 cargo jet. Misalignment of the left and right elevator and control tab surfaces with respect to one another might have been spotted during the walkaround inspection, preventing the accident.