4/20/23 

AIM 

Aeronautical Information Manual 

Explanation of Changes 

Effective:  April 20, 2023 

a.  1

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1

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20. PRECISION APPROACH SYSTEMS OTHER THAN ILS AND GLS 

This change removes references to the Transponder Landing System (TLS) from the Aeronautical Information 

Manual (AIM). 

b.  1

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2

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2. REQUIRED NAVIGATION PERFORMANCE (RNP) 

This change reduces the lateral separation minima from 30 NM to 23 NM in the oceanic airspaces of Oakland 

Air Route Traffic Control Center (ARTCC), New York ARTCC, and portions of Anchorage ARTCC. 

c.  3

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2

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1. GENERAL 

FIG 3

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1 is being updated for readability and to provide the reader with a clear interpretation of the airspace 

classes within the National Airspace System. 

d.  4

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1

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20. TRANSPONDER AND ADS

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B OUT OPERATION 

This change adds instruction to pilots participating as the lead aircraft in a visual flight rules (VFR) standard 

formation flight not receiving ATC services to squawk beacon code 1203. Additionally, paragraphs have been 

reordered and a duplicate section has been deleted. 

e.  4

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3

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6. USE OF RUNWAYS/DECLARED DISTANCES 

This change clarifies responsibilities associated with air traffic control (ATC) selecting and/or assigning 

RUNWAY IN USE/ACTIVE RUNWAY/DUTY RUNWAY. This change emphasizes that tailwind and 

crosswind considerations take precedence over delay/capacity considerations, and noise abatement 

operations/procedures. This change also provides note information that explains parallel runway number 

markings. 

f.  5

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3

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4. AIRWAYS AND ROUTE SYSTEMS 

References and a brief description of Y routes are added in paragraph 5

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4, subparagraph a3. These point the 

reader to the Aeronautical Information Publication (AIP) for detailed information on flying Y routes. 

g.  5

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6

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4. ADIZ REQUIREMENTS 

The Aeronautical Information Manual (AIM) and Aeronautical Information Publication (AIP) will be updated 

with the clarifying language previously added to the FDC NOTAM 2/8783, concerning the procedures and 

equipment required to operate into, out of, and within the Air Defense Identification Zone (ADIZ). 

h.  5

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6

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14. LAW ENFORCEMENT OPERATIONS BY CIVIL AND MILITARY ORGANIZATIONS 

This change removes paragraph 5

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6

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14 from the Aeronautical Information Manual (AIM). 

i.  7

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1. NATIONAL WEATHER SERVICE AVIATION WEATHER SERVICE PROGRAM 

7

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4. GRAPHICAL FORECASTS FOR AVIATION (GFA) 

7

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1

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6. INFLIGHT AVIATION WEATHER ADVISORIES 

7

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8. INFLIGHT WEATHER ADVISORY BROADCASTS 

This change removes the references to Traditional Alphanumeric Code (TAC) Airmen’s Meteorological 

Information (AIRMETs) over the contiguous United States. Also, it updates the description of AIRMETs and 

Significant Meteorological Information (SIGMETs) to better describe the products and how they are 

disseminated in the contiguous United States, Alaska and Hawaii. 

Explanation of Changes 

E of Chg

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