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Meaning of the AUTO modifier

Remote Pilot (Part 107) practice question 15 of 18 on Weather / Sources. ACS element UA.III.A.K4 · difficulty: recall. Want to answer it in a timed quiz? Use the Remote Pilot (Part 107) practice mode.

Question bank updated 2026-09-22

QUESTIONWhat does the modifier AUTO indicate when it appears in a METAR or SPECI?

  1. AThe report was automatically corrected after an error
  2. BThe report came from an automated source
  3. CAn observer enhanced an automated observation
Show the answer and explanation

Correct answer: B. The report came from an automated source

  • A — incorrect A corrected report sent to replace an earlier erroneous one is identified by the modifier COR, not AUTO.
  • B — correct The study guide states that if the notation AUTO is listed in the METAR/SPECI, the report came from an automated source.
  • C — incorrect AUTO indicates a fully automated source; it does not signal that a weather observer updated or enhanced the observation.

BACKGROUND

Automated weather sources such as the Automated Weather Observing System (AWOS) and the Automated Surface Observing System (ASOS) play a major role in gathering surface observations. The information for a surface observation may come from a person, an automated station, or an automated station that is updated or enhanced by a weather observer. The modifier field of a METAR or SPECI denotes whether the report came from an automated source or was corrected. AUTO means the report came from an automated source, while COR identifies a corrected report replacing an earlier one that contained an error.

STUDY TIP

Distinguish the two modifiers: AUTO says who made the observation (a machine); COR says the report is a correction. Both appear right after the date/time group.

KEY POINTS

  • AWOS and ASOS are automated sources that feed surface observations.
  • AUTO in a METAR/SPECI means the report came from an automated source.
  • COR identifies a corrected report replacing an earlier erroneous one.

SOURCES

  • remote_pilot_study_guide.txt, Chapter 3a "Surface Aviation Weather Observations" and "Aviation Routine Weather Report (METAR)", item 4 Modifier
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MORE ON WEATHER / SOURCES

SkyDrill is not affiliated with the FAA. This is an original practice item based on 14 CFR part 107, 14 CFR part 89, and the FAA Remote Pilot – Small UAS Study Guide (FAA-G-8082-22). Regulations and handbooks are revised; confirm details against the current edition.