Visual Scanning is very important to keep yourself from being involved in a midair collision. The FAA talks about it, but it is a difficult thing to illustrate. But luckily there is a way to dramatically show how your eyes can play tricks on you so that you can lose sight of (or never find in the first place!) an aircraft that is heading your way. We’ll get to that in a moment. First….

What the FAA Says About Visual Scanning

Scanning the sky for other aircraft is a very important factor in avoiding midair collisions, and it should cover all areas of the sky visible from the cockpit. Most of us are instinctively alert for potential head-on encounters with another aircraft. Actually, a study of fifty mid-air collisions revealed that only 8% were head-on. However, 42% were collisions between aircraft heading in the same direction. So, compared with opposite-direction traffic, your chances of having a midair are over five times greater with an aircraft you are overtaking or one that is overtaking you. It is necessary for you to develop and practice a technique that allows the efficient scanning of the surrounding airspace and the monitoring of cockpit instrumentation as well. You can accomplish this by performing a series of short, regularly spaced eye movements that bring successive areas of the sky into the central (foveal) visual field. To scan effectively, scan from right to left or left to right. Begin scanning at the top of the visual field in front of you and then move your eyes inward toward the bottom. Use a stop-turn-stop type eye motion. The duration of each stop should be at least one second but not longer than two to three seconds.

To see and identify objects under conditions of low ambient illumination, avoid looking directly at an object for more than 2 to 3 seconds (because it will bleach out). Instead, use the off-center viewing that consists of searching movements of the eyes (10 degrees above, below, or to either side) to locate an object, and small eye move- ments to keep the object in sight. By switching your eyes from one off-center point to another every  two to three seconds, you will continue to detect the object in the peripheral field of vision. The reason for using off-center viewing has to do with the location of rods in the periphery of the retina for night or low-intensity night vision (peripheral), and their absence in the center of the retina (fovea). Pilots should practice this off-center scanning technique to improve safety during night flights.

Now for a Dramatic (OK, sort of dramatic) Illustration of the Effect

Drivers have the same kind of issues. Motorcyclists have the problem in spades since they have to be very concerned with vehicle drivers who may not see them easily because of size and at the same time have less of a personal stake a potential accident.  The Motorcycle Safety Foundation has a page that shows how focusing on one small area can cause you to loose sight of other targets that may be right in front of you. Check out the link below…

Motion Induced Blindness