EUs may report in the remarks section significant or unusual variations in the sky condition (e.g., CLD LYR AT 400 FT ON APCH RWY 23 RPRTD BY PIREPS) that could affect flying operations. This belongs to which remark category?

• A. Supplementary Data for an Inactive or Parallel Runway.
• B. Supplementary RVR data.
• C. Representative visibility markers.
• D. Control Tower Visibility Aids.

Answer: (A)

The main idea is that remarks can carry supplementary data about weather that could impact operations on runways that are inactive or parallel to the active one. When there’s a significant or unusual sky-condition variation—like a cloud layer at 400 feet on the approach—that could affect guidance or safety for pilots using other runways, it’s documented in the supplementary data for an inactive or parallel runway so crews and controllers are aware. This category is specifically for conveying such weather nuances that aren’t part of the standard main observation but are relevant to operations on related runways. The other categories address different kinds of data (RVR specifics, general visibility markers, or visibility aids), not this type of sky-condition remark.