Most of the weather information that flight crews
receive is issued to them prior to the start of each flight
segment, but the weather used for inflight planning and
execution of an instrument approach is normally
obtained en route via government sources, company
frequency, or Aircraft Communications Addressing and
Reporting System (ACARS).
Air carriers and operators certificated under the
provisions of Part 119 (Certification: Air Carriers
and Commercial Operators) are required to use the
aeronautical weather information systems defined
in the OpsSpecs issued to that certificate holder by
the FAA. These systems may use basic FAA/National
Weather Service (NWS) weather services, contractor
or operator-proprietary weather services and/or
Enhanced Weather Information System (EWINS)
when approved in the OpsSpecs. As an integral part
of EWINS approval, the procedures for collecting,
producing, and disseminating aeronautical weather
information, as well as the crewmember and dispatcher
training to support the use of system
weather products, must be accepted or approved.
Operators not certificated under the provisions of Part
119 are encouraged to use FAA/NWS products through
Automated Flight Service Stations (AFSSs), Direct
User Access Terminal System (DUATS), and/or Flight
Information Services Data Link (FISDL). Refer to the
Aeronautical Information Manual (AIM) for more
information regarding AFSSs, DUATS, and FISDL.
The suite of available aviation weather product types is
expanding with the development of new sensor systems,
algorithms, and forecast models. The FAA and
NWS, supported by the National Center for
Atmospheric Research and the Forecast Systems
Laboratory, develop and implement new aviation weather product types through a comprehensive process
known as the Aviation Weather Technology Transfer
process. This process ensures that user needs and
technical and operational readiness requirements are
met as experimental product types mature to operational
The development of enhanced communications capabilities,
most notably the Internet, has allowed pilots
access to an ever-increasing range of weather service
providers and proprietary products. It is not the intent
of the FAA to limit operator use of this weather information.
However, pilots and operators should be aware
that weather services provided by entities other than
the FAA, NWS, or their contractors (such as the
DUATS and FISDL providers) may not meet
FAA/NWS quality control standards. Therefore, operators
and pilots contemplating use of such services
should consider the following in determining the suitability
of that service or product. In many cases, this
may be accomplished by provider disclosure or a
description of services or products:
Is the service or product applicable for aviation use?
Does the weather product or service provide
information that is usable in aeronautical decision-
Does the product or service fail to provide data
necessary to make critical aeronautical weather
Does the service provide data/products produced by
approved aviation weather information sources?
Are these data or this product modified?
If so, is the modification process described, and is
the final product in a configuration that supports
aeronautical weather decision-making?
Are the weather products professionally developed and
produced and/or quality-controlled by a qualified aviation
Does the providerís quality assurance plan include the
capability to monitor generated products and contain a
procedure to correct deficiencies as they are discovered?
Is the product output consistent with original data
Are education and training materials sufficient to enable
users to use the new product effectively?
Are the following key elements of the product intuitive
and easy for the user to interpret?
Method for displaying and decoding the
Location/mapping of the data.
Is the product suitable for use? Consider potential pilot
misunderstandings due to:
Complexity of the product.
Nonstandard display (colors, labels).
Incorrect mapping/display of data.
Incorrect overlay of weather data with other data
(terrain, navigational aids (NAVAIDs), waypoints,
Inappropriate display of missing data.
Missing or inaccurate time/date stamp on
Pilots and operators should be cautious when using
unfamiliar products, or products not supported by technical
specifications that satisfy the considerations noted
NOTE: When in doubt, use FAA/NWS products
with the consultation of an FAA AFSS specialist.