IR.V.A.K2FAA-S-ACS-8C · Nov 2023Knowledge
Satellite-based navigation (orientation, course determination, equipment, tests, regula...
Satellite-based navigation (orientation, course determination, equipment, tests, regulations, interference, appropriate use of databases, Receiver Autonomous Integrity Monitoring (RAIM), and Wide Area Augmentation System (WAAS)), including procedures for intercepting and tracking courses and arcs.
Bottom line
RAIM verifies the usability of the received GPS signals and warns the pilot of any malfunction in the navigation system, and it is required for IFR-certified GPS units. Without RAIM capability, the pilot has no assurance of the accuracy of the GPS position. The WAAS is designed to improve the accuracy, integrity, and availability of GPS signals.
Key numbers
| Number | What it means |
|---|---|
| Minimum of 4 satellites for an accurate three-dimensional GPS position | 3D position |
| 5 satellites in view, or 4 satellites plus a barometric altimeter (baro-aiding), to detect an integrity anomaly | RAIM detect |
| 6 satellites in view, or 5 with baro-aiding, to isolate and remove a corrupt satellite signal | RAIM isolate |
FAA references
- PHAK Glossary (p. G-25) — FAA-H-8083-25C (2023)
- PHAK ch. 16 (p. 16-31) — FAA-H-8083-25C (2023)
- IFH ch. 9 (p. 9-32) — FAA-H-8083-15B
- IFH ch. 9 (p. 9-26) — FAA-H-8083-15B
- RMH ch. 7 (p. 7-2) — FAA-H-8083-2A
- IPH ch. 1 (p. 1-30) — FAA-H-8083-16B
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