To protect the integrity of our aeronautical products, all notations and symbology in the original products are to be included in any tailored versions.

pattern dating chart-59

This process begins when a navigational aid is out of tolerance by at least /-6 degrees.

model to calculate the most up-to-date magnetic variation.

Objectionable airspace determinations can be based upon a number of factors including conflicting traffic patterns with another airport, hazardous runway conditions, or natural or man-made obstacles in close proximity to the landing area.

FAA Regional Airports Offices are responsible for airspace determinations.

Therefore, specialists place a line-work around the runway pattern forming a polygon (enclosed shape) for anything over 8069 feet in length.

Specialists also place these polygons around the runway pattern of aerodromes with multiple runways that are less than 8069 feet, in cases where the multiple runway pattern does not fit into the largest, circular aerodrome symbol.

That gives us about 10 days, including weekends and holidays, to compile all of the data and get the files posted by the 20th day prior.

We strive each cycle to release these products quickly, on or about 20 days prior.

* does not indicate that there is right patterned traffic for all aircraft at all times.

The type "OBJECTIONABLE" associated with an airport symbol indicates that an objectionable airspace determination has been made for the airport per FAA Order JO 7400.2 Section 4, Airport Charting and Publication of Airport Data.

Enroute charts depict airports having hard surface runways of at least 3000-foot in length.