PA.III.A.K6FAA-S-ACS-6C · Nov 2023Knowledge
Equipment issues that could cause loss of communication.
Equipment issues that could cause loss of communication.
Bottom line
For a flight in IMC, having only one radio could be considered an aircraft hazard. VHF radios are limited to line of sight transmissions, so aircraft at higher altitudes are able to transmit and receive at greater distances.
Key numbers
| Number | What it means |
|---|---|
| 118.0 MHz to 136.975 MHz | VHF band |
| One spare set of fuses, or three spare fuses of each kind required, accessible to the pilot in flight, for VFR flight at night | Night VFR fuses |
| More than 30 minutes flying time or 100 nautical miles from the nearest shore | Overwater trigger |
FAA references
- RMH ch. 3 (pp. 3-6–3-7) — FAA-H-8083-2A
- AIM 1-2-4 (Recognizing, Mitigating, and Adapting to GPS Jamming and/or Spoofing) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- PHAK ch. 14 (p. 14-22) — FAA-H-8083-25C (2023)
- 14 CFR 91.205 (Powered civil aircraft with standard U.S. airworthiness certificates: Instrument and equipment requirements.) — eCFR current as of 2026-03-05
- 14 CFR 91.511 (Communication and navigation equipment for overwater operations.) — eCFR current as of 2026-03-05
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