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AIM 

airspace, the briefer will advise you to check data as soon as practical after entering foreign airspace, unless you 

advise that you have the international cautionary advisory. 

d.  Outlook Briefing. 

You should request an Outlook Briefing whenever your proposed time of departure is 

six or more hours from the time of the briefing. The briefer will provide available forecast data applicable to the 

proposed flight. This type of briefing is provided for planning purposes only. You should obtain a Standard or 

Abbreviated Briefing prior to departure in order to obtain such items as adverse conditions, current conditions, 

updated forecasts, winds aloft and NOTAMs, etc. 

e. 

When filing a flight plan only, you will be asked if you require the latest information on adverse conditions 

pertinent to the route of flight. 

f. 

Inflight Briefing. You are encouraged to conduct a self

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briefing using online resources or obtain your 

preflight briefing by telephone or in person (Alaska only) before departure. In those cases where you need to 

obtain a preflight briefing or an update to a previous briefing by radio, you should contact the nearest FSS to 

obtain this information. After communications have been established, advise the specialist of the type briefing 

you require and provide appropriate background information. You will be provided information as specified in 

the above paragraphs, depending on the type of briefing requested. En Route advisories tailored to the phase of 

flight that begins after climb

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out and ends with descent to land are provided upon pilot request. Besides Flight 

Service, there are other resources available to the pilot in flight, including: 

Automatic Dependent Surveillance

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Broadcast (ADS

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B)

. Free traffic, weather, and flight information are 

available on ADS

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B In receivers that can receive data over 978 MHz (UAT) broadcasts. These services are 

available across the nation to aircraft owners who equip with ADS

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B In, with further advances coming from 

airborne and runway traffic awareness. Even search

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and

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rescue operations benefit from accurate ADS

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B 

tracking. 

Flight Information Services

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Broadcast (FIS

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B). 

FIS

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B is a free service; but is only available to aircraft that can 

receive data over 978 MHz (UAT). FIS

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B automatically transmits a wide range of weather products with national 

and regional focus to all equipped aircraft. Having current weather and aeronautical information in the cockpit 

helps pilots plan more safe and efficient flight paths, as well as make strategic decisions during flight to avoid 

potentially hazardous weather. 

Pilots are encouraged to provide a continuous exchange of information on weather, winds, turbulence, flight 

visibility, icing, etc., between pilots and inflight specialists. Pilots should report good weather as well as bad, and 

confirm expected conditions as well as unexpected. Remember that weather conditions can change rapidly and 

that a “go or no go” decision, as mentioned in paragraph 7

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4b2, should be assessed at all phases of flight. 

g. 

Following any briefing, feel free to ask for any information that you or the briefer may have missed or are 

not understood. This way, the briefer is able to present the information in a logical sequence, and lessens the 

chance of important items being overlooked. 

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6.  Inflight Aviation Weather Advisories 

a. 

Inflight Aviation Weather Advisories are forecasts to advise en route aircraft of development of potentially 

hazardous weather. Inflight aviation weather advisories in the conterminous U.S. are issued by the Aviation 

Weather Center (AWC) in Kansas City, MO, as well as 20 Center Weather Service Units (CWSU) associated with 

ARTCCs. AWC also issues advisories for portions of the Gulf of Mexico, Atlantic and Pacific Oceans, which 

are under the control of ARTCCs with Oceanic flight information regions (FIRs). The Weather Forecast Office 

(WFO) in Honolulu issues advisories for the Hawaiian Islands and a large portion of the Pacific Ocean. In Alaska, 

the Alaska Aviation Weather Unit (AAWU) issues inflight aviation weather advisories along with the Anchorage 

CWSU. All heights are referenced MSL, except in the case of ceilings (CIG) which indicate AGL. 

Meteorology 

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