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Supplementary Weather Product Description

The definitions for weather product status can be found in FSIMS Order 8900.1, paragraph 3-2073. These definitions technically refer to air carriers but Flight Standards has consistently used this definition for General Aviation as well. Similar definitions that may cover GA are contained in AIM section 7-1-3.

For reference the relevant FSIMS paragraph is provided below:


A. The development of new aviation weather products is an evolutionary process with distinct stages of product maturity. The growing demand for new weather products and the corresponding increase in research and development to meet that demand, along with relatively unfettered access to weather information via the public Internet, created confusion within the aviation community regarding the relationship between regulatory requirements and new weather products. Consequently, the FAA finds it necessary to differentiate between those weather products that may be used to comply with regulatory requirements and those that may only be used to improve situational awareness. To clarify the proper use of aviation weather products to meet the requirements of the regulations, the FAA developed the following definitions:

  1. Primary Weather Product. An aviation weather product that meets all the regulatory requirements and safety needs, for use in making flight-related aviation weather decisions.
  2. Supplementary Weather Product. A aviation weather product that may be used for enhanced situational awareness. If used, a supplementary weather product must only be used in conjunction with one or more primary weather products. In addition, the FAA may further restrict the use of supplementary weather products through limitations described in the product label.

NOTE: An aviation weather product produced by the Federal Government is a primary product unless designated as a supplementary product by the FAA.

B. In developing the definitions of primary and supplementary weather products, it is not the intent of the FAA to change or increase the regulatory burden upon certificate holders. Rather, the definitions are meant to eliminate confusion by differentiating between products that may be used to meet regulatory requirements and other products that may only be used to improve situational awareness.

C. All flight-related, aviation weather decisions must be based on primary weather products. Supplementary weather products augment the primary products by providing additional weather information, but may not be used as stand-alone products to meet aviation weather regulatory requirements or without the relevant primary products. When discrepancies exist between primary and supplementary products pertaining to the same weather phenomena, users must base flight-related decisions on the primary weather product. Furthermore, multiple primary products may be necessary to meet all aviation weather regulatory requirements.

D. As previously noted, the FAA may choose to restrict certain weather products to specific types of usage or classes of user. Any limitations imposed by the FAA on the use of a product will appear in the product label.