See and Avoid
The “see and avoid” method of collision avoidance is used as the primary means
of separation between aircraft operating under visual flight rules. Just as it
sounds, this method involves looking for air traffic and maneuvering as
While your eyes are able to see a wide area at once, only a small area in the
center of the visual field is sharply focused. As a result, pilot’s use a visual
scanning technique in order to examine each area of sky for other
An airplane is visible ten times further away if you are looking directly at it.
Visual scanning technique involves systematically looking at every portion of
To accomplish this, use short and regularly spaced eye movements. Examine about
ten degrees of sky at a time, and stay focused on each ten degree portion of the
sky for at least one second. This allows your mind enough time to examine what
your eyes are focused on.
Since other aircraft might be climbing or descending, scan above and below the
horizon, as well as at your own altitude.
As a general rule, you keep your eyes focused no more than 4 to 5 seconds on
anything inside the airplane for every 16 seconds spent scanning outside the
airplane. In other words, you eyes should be focused inside the airplane no more
than 1/4 to 1/3 of the time.
Whenever you are practicing maneuvers, visually scan the entire area for traffic
prior to beginning a maneuver.
When you see another aircraft, notice its altitude relative to yours. If an
aircraft appears to be above the horizon, it is probably on a higher flight
path. An aircraft below the horizon is probably at a lower altitude. However,
just because an aircraft is currently at a different altitude does not
necessarily mean it will stay there. Remember to watch for aircraft which could
be climbing or descending.
Also watch the aircraft’s relative motion. If an aircraft appears to have no
motion relative to your airplane, it is likely flying directly toward you.
Because of this lack of relative motion and the aerodynamic design of aircraft,
an aircraft approaching head on is more difficult to see.
High Hazard Areas
Be aware of areas that are more congested. Most mid air collisions occur during
times of good weather, usually near a high traffic area. Examples of high hazard
areas include navigational aids, airports, along federal airways, and in areas
used for pilot training.
It is recommended to execute gentle banks when climbing or descending in a high
hazard area. This allows you to better see areas that may be blocked by
portions of your own airplane. The FAA recommends gentle banks when
climbing or descending along a federal airway. These airways are primarily
used by aircraft under instrument flight rules, where air traffic control radar
coverage is not available. Pilot's of VFR aircraft can use them, as well,
at their own discretion. If you choose to do so, these gentle banks are
recommended because you may be climbing or descending through several airplanes
along your same route of flight.
Obstructions to Visibility
Keep a clean windshield. It’s hard to spot other aircraft during the flight if
you are looking through a windshield that is dirty or covered in smashed bugs.
Other obstructions to visibility include portions of the airplane itself. It is
fine to occasionally perform gentle banks left and right in order to allow you
to scan areas blocked by portions of the airplane.
Organize materials needed during the flight beforehand, and make note of radio
frequencies to be used. This will reduce the amount of time spent looking inside
the airplane during the flight.
Scanning for Traffic at Night
Your eyes are contain two different types of light receptors, called cones and
rods. The cones do a good job of providing sharp detail and good color
depth. However, cones require bright light for their operation. Rods
are adapted to work in low light conditions, but provide little detail or color
Cones are concentrated in the center of your visual field, providing the sharp,
high color area of vision you use in bright light conditions. The rods are
distributed elsewhere in the eye, providing you a peripheral and night vision.
As a result of this distribution of cones and rods, the area you see most
clearly with during the day becomes more or less blind at night. In low
light conditions, we become more reliant on our peripheral vision.
When scanning for traffic at night, you have a harder time seeing objects you
are looking at directly. To most effectively scan for traffic at night,
use your peripheral vision. This method of scanning is called off center