AI.II.B.K5FAA-S-ACS-25 · Nov 2023Knowledge
Aircraft blind spots and clearing procedures.
Aircraft blind spots and clearing procedures.
Bottom line
The see and avoid concept requires vigilance at all times by each person operating an aircraft, whether the operation is conducted under IFR or VFR. Appropriate clearing procedures should precede the execution of all turns. Blind spots are caused by fixed aircraft structures such as doorposts and wings; high-wing airplanes have restricted visibility above, while low-wing airplanes have limited visibility below.
Key numbers
| Number | What it means |
|---|---|
| Each scanning eye movement should not exceed 10 degrees. | Scan movement |
| Each area observed in the scan should be observed for at least 1 second to enable detection. | Scan dwell |
| At night, the night-blind spot involves an area between 5 and 10 degrees wide in the center of the visual field. | Night blind spot |
| Off-center viewing requires looking approximately 10 degrees above, below, or to either side of an object. | Off-center view |
| Pilots should always clear the area with two 90° clearing turns before ground reference maneuvers. | Clearing turns |
FAA references
- AFH ch. 1 (pp. 1-10–1-11) — FAA-H-8083-3C
- AIM 4-4-15 (Use of Visual Clearing Procedures and Scanning Techniques) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- AC 90-48 ch. 4 — AC No: 90-48E
- AFH ch. 7 (pp. 7-1–7-2) — FAA-H-8083-3C
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