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AI.II.B.K4FAA-S-ACS-25 · Nov 2023Knowledge

Visual scanning procedure and the importance of peripheral vision.

ACS element text (the applicant demonstrates understanding of)

Visual scanning procedure and the importance of peripheral vision.

Bottom line

Effective scanning is accomplished with a series of short, regularly-spaced eye movements that bring successive areas of the sky into the central visual field.

Key numbers

Key numbers for Visual scanning procedure and the importance of peripheral vision.
NumberWhat it means
10 degrees per eye movementMax scan step
1 second per areaMin dwell
10 to 15 degreesFocus arc
5 to 10 degrees wide, center of visual fieldNight blind spot
12.5 secondsAvoid time

FAA references

  1. AFH ch. 1 (pp. 1-10–1-11) — FAA-H-8083-3C
  2. AC 90-48, paras. 8.1.4, 8.1.5, 8.1.6, 8.1.7 — AC No: 90-48E
  3. AC 90-48 ch. 4 — AC No: 90-48E
  4. PHAK ch. 17 (p. 17-23) — FAA-H-8083-25C (2023)
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