IR.II.C.K2FAA-S-ACS-8C · Nov 2023Knowledge
IFR airworthiness, including aircraft inspection requirements and required equipment fo...
IFR airworthiness, including aircraft inspection requirements and required equipment for IFR flight.
Bottom line
Airworthiness Directives (AD) must be complied with within the required time limit, and the fact of compliance, the date of compliance, and the method of compliance must be recorded in the aircraft’s maintenance records.
Key numbers
| Number | What it means |
|---|---|
| Within 24 months, for IFR in controlled airspace | Altimeter check |
| Every 30 days, when using VOR for IFR | VOR check |
| No more than 10 hours, to reach an inspection location | 100-hour grace |
| Within the last 12 months | ELT inspection |
FAA references
- PHAK ch. 9 (pp. 9-8–9-9) — FAA-H-8083-25C (2023)
- AFH ch. 2 (pp. 2-2–2-4) — FAA-H-8083-3C
- AFH Glossary (p. G-2) — FAA-H-8083-3C
- 14 CFR 91.205 (Powered civil aircraft with standard U.S. airworthiness certificates: Instrument and equipment requirements.) — eCFR current as of 2026-03-05
- IFH ch. 9 (p. 9-26) — FAA-H-8083-15B
- AFH ch. 1 (p. 1-4) — FAA-H-8083-3C
- PHAK ch. 9 (p. 9-8) — FAA-H-8083-25C (2023)
- 14 CFR 91.327 (Aircraft issued a special airworthiness certificate in the light-sport category: Operating limitations.) — eCFR current as of 2026-03-05
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