During daytime collision avoidance scanning, how should eye movements be limited?

• A. Not exceed 20 degrees and view each sector at least 0.5 seconds
• B. Not exceed 10 degrees and view each sector at least 1 second
• C. Move eyes rapidly across the sky with no fixed sector duration
• D. Keep eyes fixed on one sector until it is clear of traffic

Answer: (B)

During daytime collision avoidance scanning, you use a deliberate, steady pattern with small eye movements to cover the sky without missing traffic. Limit the glance to about ten degrees at a time, and spend at least one second on each sector. This cadence gives your eyes enough time to detect potential aircraft and recognize relative motion against the background, while the small steps ensure you don’t skip portions of the sky.

If you sweep too wide a angle, you risk leapfrogging over possible targets; if you shorten the sector dwell time to a half second, you may not notice aircraft that are only briefly visible or that require momentary attention to detect movement. Moving eyes rapidly with no fixed duration makes the scan unfocused and easy to miss. Keeping the gaze fixed on one sector ignores aircraft that could be approaching from other directions.