Which statement best describes how on-site weather observations are used during an investigation?

• A. They are used to determine the pilot's training status.
• B. They replace METAR data entirely.
• C. They are used to identify unrelated regulatory violations.
• D. They corroborate other weather data and help understand conditions at the crash site.

Answer: (D)

On-site weather observations provide location-specific, real-time information that helps investigators understand the actual conditions at the crash site. By comparing what’s observed on the ground with METARs, PIREPs, radar, and other weather data, investigators can verify wind speed and direction, visibility, precipitation, cloud cover, temperature, and potential icing that were present at the scene. This corroboration is crucial because conditions at the site may differ from airport reports due to proximity to terrain, microclimates, or timing differences. Understanding these conditions as they existed at the crash site helps determine weather-related factors that could have influenced the flight path, performance, or survivability. They are not used to assess pilot training, do not replace METAR data, and do not identify unrelated regulatory violations.