FlyCurrentFLYCURRENT
AI.II.I.K11FAA-S-ACS-25 · Nov 2023Knowledge

Planned calculations versus actual results and required corrections.

ACS element text (the applicant demonstrates understanding of)

Planned calculations versus actual results and required corrections.

Bottom line

While descending, the pilot can check the progress periodically, and estimating using round numbers keeps the calculation simple. In all cases, the pilot should check progress during the descent and continue to adjust as necessary.

Key numbers

Key numbers for Planned calculations versus actual results and required corrections.
NumberWhat it means
1 mile per 10 knots of wind at cruise altitudeWind adjust
approximately 120 miles from the airport when 35,000 feet above airport elevationExample TOD
25,000 feet at 75 miles out; 20,000 feet at 60 milesProgress check
1,000 feet per minute, usually acceptable until reaching the desired pathImmediate descent

FAA references

  1. AFH ch. 16 (pp. 16-18–16-19) — FAA-H-8083-3C
  2. PHAK ch. 2 (p. 2-26) — FAA-H-8083-25C (2023)
  3. RMH ch. 3 (p. 3-4) — FAA-H-8083-2A
Members lesson

Build understanding you can use

Unlock the full lesson and continue studying this element.

  • Full teaching sections: What it is; Key points; Rules and numbers; How it is done
  • Check your understanding with answers you can reveal
  • Common mistakes paired with the FAA facts that correct them
View membership options