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CA.II.A.K4FAA-S-ACS-7B · Nov 2023Knowledge

Environmental factors, including weather, terrain, route selection, and obstructions.

ACS element text (the applicant demonstrates understanding of)

Environmental factors, including weather, terrain, route selection, and obstructions.

Bottom line

Marginal weather or environmental conditions is an identified hazard because it may result in the pilot A good preflight should include a review of the proposed route, possible alternate routes, terrain, and local, en route, and destination weather.

Key numbers

Key numbers for Environmental factors, including weather, terrain, route selection, and obstructions.
NumberWhat it means
at least 20 miSevere TS avoid
at least 40 mi separationBetween echoes
35,000 ft or higherHazardous TS tops
over 1,500 ft AGL terrainTV towers
more than 3,000 ft above terrainCruise altitude rule

FAA references

  1. AFH ch. 2 (p. 2-12) — FAA-H-8083-3C
  2. SEA ch. 7 (p. 7-3) — FAA-H-8083-23
  3. AWH ch. 22 (pp. 22-21–22-22) — FAA-H-8083-28A
  4. PHAK ch. 16 (p. 16-18) — FAA-H-8083-25C (2023)
  5. AIH ch. 1 (pp. 1-5–1-6) — FAA-H-8083-9B
  6. RMH ch. 3 (p. 3-7) — FAA-H-8083-2A
  7. AWH App. D (pp. D-9–D-10) — FAA-H-8083-28A
  8. AFH ch. 13 (p. 13-16) — FAA-H-8083-3C
  9. RMH ch. 5 (p. 5-2) — FAA-H-8083-2A
  10. PHAK ch. 2 (p. 2-22) — FAA-H-8083-25C (2023)
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