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ACRO E-mail Archive Thread: [Acro] Re: Section 91.303

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ACRO E-mail Archive Thread: [Acro] Re: Section 91.303


Thread: [Acro] Re: Section 91.303

Message: [Acro] Re: Section 91.303

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From: Flyinverted at

Date: Sun, 17 Mar 2002 03:46:55 UTC


Aeronautical Charts used to be produced by NOAA (National Oceanic and 
Atmospheric Administration). That job now belongs to the FAA under their 
National Aeronautical Charting Office.

The yellow depicted areas on the sectionals are Category 1 and 2  Large 
Cities and Towns as defined by the NOAA according to population density. By 
the NOAA definitions these would be considered congested areas. One of the 
criteria I believe is that to be Category 1 or 2 the area must be an 
incorporated city or township therefore most rural areas would not qualify 
even though the population density may be quite high in some areas. 

By FAA definition a congested area is any open air assembly of persons or 
dwelling and doesnt depend on population density or incorporation status of 
the area. The FAA definition is based on interpretations of the AIM, Part 91 
and Part 137 (Agricultural Ops) and is not set forth in Part 1 which is why 
its a good idea to check with the local FSDO regarding their interpretation

One is a cartographer's definition and the other the regulatory definition. 
As a pilot one would probably want to stick with the regulatory definition of 
congested airspace.

NOAA used to publish a 40 or so page guide that explains all the details of a 
sectional chart including the yellow areas but I dont know where it could be 
obtained these days. Maybe from the new FAA NACO.

Ed Gonzalez
Pitts S-1S, N431ED
Attachement 1: part2.html


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