Which of the following is NOT an acceptable source of weather data for flight planning?

The choice of the Agricultural Weather Center (AWC) as an unacceptable source of weather data for flight planning stems from the primary focus of this organization. The AWC is primarily dedicated to providing weather information that is specifically tailored to the agricultural community. This includes forecasts and analyses that are crucial for farming and agricultural activities, rather than the specialized meteorological data needed for aviation purposes.

In contrast, the other sources listed—Aviation Digital Data Service (ADDS), National Weather Service (NWS), and Flight Service Station (FSS)—are well-established entities that provide comprehensive weather information relevant to aviation. The ADDS offers a variety of aviation weather products, the NWS provides critical weather alerts and forecasts that affect air travel, and FSS serves as a direct source for pilots to obtain updated weather briefings necessary for safe flight planning. Thus, while AWC may provide useful weather data in a general context, it is not reliable for making aviation-specific decisions that require precise and relevant meteorological information.