IR.VI.A.K3FAA-S-ACS-8C · Nov 2023Knowledge
Ground-based and satellite-based navigation systems used for a non-precision approach.
Ground-based and satellite-based navigation systems used for a non-precision approach.
Bottom line
Conventional non-precision approaches include Localizer (LOC) only and VOR approaches, while NPA RNAV approaches include LNAV and Localizer Performance (LP). GPS is a satellite-based radio positioning, navigation, and time-transfer system.
Key numbers
| Number | What it means |
|---|---|
| minimum of four satellites above the mask angle | GPS satellites |
| as low as 250 feet above the ground in IMC | Dive and drive |
| approximately 50 ft above the landing runway threshold | CDFA end point |
| since the beginning of the 6th month before that use | NPA recency |
FAA references
- AC 120-108 ch. 4 List of Tables — AC No: 120-108A
- AFH Glossary (p. G-7) — FAA-H-8083-3C
- IFH ch. 9 (pp. 9-26–9-27) — FAA-H-8083-15B
- IFH ch. 9 (p. 9-32) — FAA-H-8083-15B
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