PA.III.B.K4FAA-S-ACS-6C · Nov 2023Knowledge
Use of automated weather and airport information.
Use of automated weather and airport information.
Bottom line
ASOS is a weather reporting system that provides surface observations every minute via digitized voice broadcasts and printed reports. At uncontrolled airports with ASOS/AWOS ground-to-air broadcast capability, the one-minute updated airport weather should be available within approximately 25 NM of the airport below 10,000 feet.
Key numbers
| Number | What it means |
|---|---|
| every minute | ASOS update |
| approximately 25 NM below 10,000 feet, at uncontrolled ASOS/AWOS airports with ground-to-air broadcast capability | Broadcast range |
FAA references
- IFH Glossary (p. G-3) — FAA-H-8083-15B
- AIM 4-3-27 (Operations at Uncontrolled Airports With Automated Surface Observing System (ASOS)/Automated Weather Observing System (AWOS)) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- PHAK ch. 13 (p. 13-2) — FAA-H-8083-25C (2023)
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