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CA.IV.E.K1FAA-S-ACS-7B · Nov 2023Knowledge

Effects of atmospheric conditions, including wind, on takeoff and climb performance.

ACS element text (the applicant demonstrates understanding of)

Effects of atmospheric conditions, including wind, on takeoff and climb performance.

Bottom line

High density altitude reduces aircraft performance: it reduces normal horsepower output and propeller efficiency, increases runway length requirements for takeoffs and landings, and decreases rate of climb. A heavier gross weight results in a longer takeoff run and shallower climb.

Key numbers

Key numbers for Effects of atmospheric conditions, including wind, on takeoff and climb performance.
NumberWhat it means
70 percent of lift-off airspeed by runway midpoint, or abortHalfway check
broadcast at airports 2,000 feet elevation and higher when temperature reaches a predetermined levelDA advisory
1,500 to 2,000 feet per minute on the leeward side of mountain passesLeeward downdrafts

FAA references

  1. AIM 7-6-7 (Mountain Flying) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
  2. PHAK ch. 5 (p. 5-42) — FAA-H-8083-25C (2023)
  3. AIM 7-6-8 (Use of Runway Half-way Signs at Unimproved Airports) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
  4. PHAK ch. 11 (p. 11-5) — FAA-H-8083-25C (2023)
  5. AFH ch. 9 (p. 9-12) — FAA-H-8083-3C
  6. RMH ch. 3 (p. 3-7) — FAA-H-8083-2A
  7. RMH ch. 3 (p. 3-6) — FAA-H-8083-2A
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