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IR.II.B.K3FAA-S-ACS-8C · Nov 2023Knowledge

b. Area navigation (RNAV), global positioning system (GPS), Wide Area Augmentation Syst...

ACS element text (the applicant demonstrates understanding of)

b. Area navigation (RNAV), global positioning system (GPS), Wide Area Augmentation System (WAAS), flight management system (FMS), autopilot Use of an electronic flight bag (EFB), if used.

Bottom line

WAAS is a satellite-based augmentation system (SBAS) included under GNSS. An EFB may be used in flight in lieu of paper reference material at the decision of the aircraft operator and the pilot in command.

Key numbers

Key numbers for b. Area navigation (RNAV), global positioning system (GPS), Wide Area Augmentation Syst...
NumberWhat it means
at or above FL 240FL 240 rule
notify ATC immediatelyFailure action

FAA references

  1. AC 90-105 Appendix J — AC No: 90-105A
  2. AC 91-78 ch. 20 , Electronic Aeronautical Chart Display. — AC No: 91-78A
  3. 14 CFR 91.205 (Powered civil aircraft with standard U.S. airworthiness certificates: Instrument and equipment requirements.) — eCFR current as of 2026-03-05
  4. RMH Glossary — FAA-H-8083-2A
  5. AC 90-100, para. 4m — AC No: 90-100A
  6. RMH ch. 7 (pp. 7-3–7-4) — FAA-H-8083-2A
  7. AFH ch. 13 (p. 13-8) — FAA-H-8083-3C
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