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AA.I.B.K7FAA-S-ACS-11A · Nov 2023Knowledge

Clean wing concept; deicing and anti-icing procedures, including use of appropriate dei...

ACS element text (the applicant demonstrates understanding of)

Clean wing concept; deicing and anti-icing procedures, including use of appropriate deice fluid, holdover tables, calculating hold-over times, and pre-takeoff contamination checks.

Bottom line

The applicant demonstrates understanding of: Clean wing concept; deicing and anti-icing procedures, including use of appropriate deice fluid, hold- over tables, calculating hold-over times, and pre-takeoff contamination checks.

Key numbers

Key numbers for Clean wing concept; deicing and anti-icing procedures, including use of appropriate dei...
NumberWhat it means
40 percentDrag increase
rotation speed less than 110 knotsFluid limit
approximately 10 minutesHoldover example

FAA references

  1. AC 20-117, para. 4a — AC No: 20-117
  2. AC 91-74, para. 7-1 — AC No: 91-74A
  3. AC 20-117, paras. 4f, 4g — AC No: 20-117
  4. 14 CFR 91.527 (Operating in icing conditions.) — eCFR current as of 2026-03-05
  5. AC 91-74 Appendix 3 — AC No: 91-74A
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