AA.VI.C.K5FAA-S-ACS-11A · Nov 2023Knowledge
Ground-based and satellite-based navigation systems (orientation, course determination,...
Ground-based and satellite-based navigation systems (orientation, course determination, equipment, tests and regulations, interference, appropriate use of navigation data, signal integrity).
Bottom line
In situations where the loss of RAIM capability is predicted to occur, the flight must rely on other approved equipment, delay departure, or cancel the flight.
Key numbers
| Number | What it means |
|---|---|
| minimum of four satellites above the mask angle | GPS satellites |
| typically less than 100 feet, from equipment characteristics and geometric factors | GPS error |
| plus or minus 4 degrees, using an FAA-operated or approved test signal | Ground VOR check |
FAA references
- AC 90-100, paras. 4d, 4e, 4f, 4h, 4i, 4k — AC No: 90-100A
- IFH ch. 9 (pp. 9-26–9-27) — FAA-H-8083-15B
- IFH ch. 9 (p. 9-31) — FAA-H-8083-15B
- 14 CFR 91.171 (VOR equipment check for IFR operations.) — eCFR current as of 2026-03-05
- 14 CFR 91.227 (Automatic Dependent Surveillance-Broadcast (ADS-B) Out equipment performance requirements.) — eCFR current as of 2026-03-05
- AC 90-100 Appendix 3 — AC No: 90-100A
- 14 CFR 91.411 (Altimeter system and altitude reporting equipment tests and inspections.) — eCFR current as of 2026-03-05
- AC 90-100 Appendix 1 — AC No: 90-100A
- AFH ch. 5, Human Factors (p. 5-2) — FAA-H-8083-3C
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