IR.I.C.K3aFAA-S-ACS-8C · Nov 2023Knowledge
a. Time, climb and descent rates, course, distance, heading, true airspeed, and grounds...
Calculating: a. Time, climb and descent rates, course, distance, heading, true airspeed, and groundspeed
Bottom line
Dead reckoning is navigation solely by means of computations based on time, airspeed, distance, and direction. The products derived from these variables, when adjusted by wind speed and velocity, are heading and GS. GS, heading, and time for any flight can be determined by using the wind triangle.
Key numbers
| Number | What it means |
|---|---|
| planned descent in thousands of feet × 3, plus distance for speed reductions, for a straight-in VFR approach without factoring wind | TOD rule |
| 1 mile per 10 knots of head/tail wind at cruise altitude | Wind adjust |
| 1 NM wide per degree at 60 NM from the station | Radial width |
| not to exceed 90 degrees | Max intercept |
FAA references
- PHAK ch. 16 (p. 16-13) — FAA-H-8083-25C (2023)
- AFH ch. 16 (pp. 16-17–16-18) — FAA-H-8083-3C
- PHAK ch. 16 (p. 16-27) — FAA-H-8083-25C (2023)
- PHAK ch. 16 (p. 16-9) — FAA-H-8083-25C (2023)
- PHAK ch. 16 (p. 16-12) — FAA-H-8083-25C (2023)
- AFH ch. 3 (p. 3-23) — FAA-H-8083-3C
- 14 CFR 91.181 (Course to be flown.) — eCFR current as of 2026-03-05
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