AIS subscriber files effective date November 27, 2025.

Dear Subscribers,

For the November 27, 2025 subscriber files, the files incorporate data 
published in the daily National Flight Data Digest (NFDD) through
 
    NFDD 205 dated 10/27/2025.  

The November 27, 2025 cycle is a 56 Day Major Cycle subscriber set. 

By FAA policy and order, some NASR resources, generally categorized as 
"Enroute", are only updated on a 56 day charting basis. The following legacy 
text subscriber files are included in the 28 day "Change Notice" subscriber 
set, but will not contain new data: ARB, ATS, AWY, CDR, MTR, PFR, PJA, STARDP, 
and WXL. They will be the same files produced for the previous 56 day AIRAC 
cycle. The SAA AIXM 5.0 set file and the AWY AIXM 5.1 file will be updated on 
the 56 day major cycle.

AIRAC CYCLE PERIOD: 28 DAY CLARIFICATION

    We are now issuing these products on a 28 day cycle periodicity. 
    Subscriber files have previously reported according to a 56 day AIRAC 
    cycle periodicity. 

    The subscriber file sets will be posted 28 days prior to the effective 
    date. The files will contain data that is updated for that cycle and has 
    met the cutoff for entry. 

    As these subscriber files are complete snapshots of their respective 
    resource areas, any updates published in a "Change Notice" set will also 
    be included in the next 56 day major cycle set. If your business processes 
    are based on a 56 day cycle, you can continue to use the 56 day major 
    cycle products and will not be missing data.

DATUM

    The legacy text subscriber files do not cite a datum for geodetic 
    coordinates. All US coordinates information provided is currently 
    reference NAD 83.

ATS NON-REGULATORY AIRWAYS (ATS.txt) ADDITION OF AK CAPSTONE ROUTES

    Beginning with the August 7, 2025 effective date, four AK Capstone Routes 
    were added to the ATS.txt file. Users must have specific FAA authorization, 
    through Operation Specifications or Letter of Authorization, obtained from 
    Flight Standards to use the following routes: R2010, R2015, R2020, R2025. 
    The aircrafts lateral deviation display scaling must support the RNP 1 
    EnRoute Operations.

SUNSETTING OF LEGACY .TXT SUBSCRIBER FILES

    FAA is in the process of sunsetting the legacy .txt NASR subscriber files. 
    The timeframe for sunsetting .txt subscriber files is targeted for the 
    24 Dec 2026 AIRAC cycle. The .txt format NASR subscriber files will be 
    replaced with a set of .csv format subscriber files, which are currently 
    available. A Legacy TXT to CSV Mapping Document is available for download 
    via the main 28-Day Subscription page to ease transition.

    NOTE: Beginning with the 22 January 2026 AIRAC cycle, .txt subscriber files 
    will no longer contain new data entrants in NASR. New data entrants will be 
    available only in .csv subscriber files. 

AIRWAY DYNAMIC MAGNETIC VARIATION (ATS.txt, AWY.txt)

    The airway dynamic magnetic variation (SEGMENT MAGNETIC COURSE and SEGMENT 
    MAGNETIC COURSE - OPPOSITE DIRECTION) is recalculated yearly, based on 
    the magnetic epoch. The updates will be published on the next 56 Day Major 
    Cycle following the first 56 day Major Cycle whose data processing period 
    falls fully within the calendar year. For 2025, this was the April 17, 2025 
    effective date.
    
AIRWAY MAXIMUM AUTHORIZED ALTITUDE DATA (AWY.txt)
    Starting with the May 16, 2024 effective cycle.  
    The airway point to point Maximum Authorized Altitude (MAA) for Victor (V) 
    and Colored Airways (A,B,G,R) will be fully populated when Altitude data 
    is present for a given Point.  Currently, a null assumes 17500.

AIRWAY MAXIMUM AUTHORIZED ALTITUDE DATA (AWY.txt)
    Effective July 11, 2024, The Maximum Authorized Altitude (MAA) for 19 Hawaii 
    Victor (V) Airways is changed from 17500 to 45000. 

ARTCC BOUNDARY (ARB.txt) CLARIFICATION

    Some of the ARTCC boundaries defined by the ARTCC facility are composed of 
    more than a single closed shape. Due to the format constraints and naming 
    conventions of the legacy ARB file it is not possible to publish each 
    shape separately. In these cases it is necessary to read the point 
    description text for the key phrase "TO POINT OF BEGINNING" to identify 
    where the shape returns to the beginning and forms a closed shape. This is 
    currently found in the ZMA BDRY, ZAN BDRY, ZNY HIGH, and ZOA UTA 
    boundaries. This is not a change to the file, it is only clarification of 
    the practice that has existed for years.

ATS NON-REGULATORY AIRWAYS (ATS.txt) PREFERRED DIRECTION INFORMATION

    All U.S. airways are bidirectional. There are some airways that Air 
    Traffic Control (ATC) prefers traffic flow in one direction. However, ATC 
    may clear traffic in either direction as needed. Preferred directionality 
    for all airways in the NAS will be published in the High Single Direction 
    (HSD) Preferred IFR Route (PFR.txt). For clarity in defining preferred 
    routing for ATS airways the following change will be made in NASR: 

    The preferred direction reference for nine non-regulatory ATS airways in 
    the ats.txt file was indicated in the "Mea Dir" column and the "Remarks 
    Text" column in Rec Type RMK. Effective 23 Feb 2023, the direction 
    information was removed from the ats.txt subscriber file and added in 
    the Preferred Route (pfr.txt) subscriber file in a PFR_TYPE HSD (High 
    Single Direction) preferred route.

    NOTE: In order to maintain consistency in NASR all references, titles, and 
    headings to SINGLE DIRECTION will be removed and or retitled to 
    indicate PREFERRED DIRECTION in a future release. 

AIRPORT (APT.txt) NEW FUEL TYPES

    Three new fuel types are available in the .txt NASR subscriber files 
    beginning with the 27 November 2025 AIRAC cycle. 

    H  Hydrogen
    G100  Unleaded Grade 100 gasoline. Note: G100 is the same as G100UL in 
           the .csv subscriber file 
    100R - Unleaded Grade 100 gasoline

    NOTE: G100 and G100UL are the same fuel type. Due to character limit 
    constraints associated with the .txt subscriber file format, G100UL has been 
    truncated to G100.  

AIRPORT (APT.txt) BASED AIRCRAFT AND ANNUAL OPERATIONS DATA

    The based aircraft and annual operations data in the apt.txt data set, 
    elements A90-96 and A100-105, has been removed from the NASR database and  
    is no longer contained in NASR Subscriber files as of the September 5, 
    2024 effective date. These fields in the legacy apt.txt subscriber file 
    are NULL. Information regarding based aircraft can be found at the 
    National Based Aircraft Inventory Program located on the web at 
    https://basedaircraft.com/. Information on aircraft operations is available
    from FAA's FAA Aviation System Performance Metrics https://aspm.faa.gov.
    
AIRPORT (APT.txt) RUNWAY END GRADIENT DATA, BEACON, ARFF

    The runway end gradient data in the apt.txt data set, element E40, 
    contained erroneous and incomplete data and should not be used for any 
    purpose. All runway end gradient data has been removed as of the April 25, 
    2019 effective date NASR Subscriber files. The runway end gradient data 
    field will publish with null values while Aeronautical Information 
    Services works to ensure all runway end gradient data can be safely 
    repopulated.

AIRPORT (APT.txt) RUNWAY SURFACE TREATMENT

    The RWY record contains information on Runway Surface Treatment and has
    allowed for a null entry.  For data consistency, null will be modified to 
    "NONE" with the exception of pseudo runways (those containing "X"). 
    
    Effective with the 15 June 2023 cycle, Runway Surface Treatment in the RWY 
    record of the APT.txt subscriber should only contain null for pseudo 
    runways. 

TOWER (TWR.txt) FREQUENCY SCRUB

    The frequency number and sectorization data are concatenated together for 
    output to the TWR subscriber file in TWR3 & TWR7 records. There was no set 
    delimiter between the end of a frequency number and start of the 
    sectorization data. A semicolon has been prepended to the sectorization 
    field in NASR so that the concatenated export will contain the semicolon 
    as a set delimiter between frequency number and sectorization data.

TOWER (TWR.txt) NUMBER OF HOURS OF DAILY OPERATION AND REGULARITY

    The TWR1 record contains two fields, both identified as element number 
    TA55, that summarize the number of daily hours (e.g 16) and weekly 
    regularity (e.g WDO). At some point, this data will be removed. The 
    previously announced date of December 31, 2020 has been delayed. When this 
    data is removed, the columns will remain in the layout, but the data will 
    be blank. This does not change the actual hours of operation data that 
    will continue to be published in the TWR2 records.

TOWER (TWR.txt) RADAR SCRUB

    The TWR5 record contains information on existence of RADAR and the Type
    of RADAR at the Facility.  RADAR Types are being reviewed and RADAR Type
    Numbers will no longer be included with short range RADAR information.
    For example, ASR-11 will be ASR. 
    
    Effective with the 13 July 2023 cycle, TYPE OF RADAR AT THE TOWER fields 
    in the TWR5 records will no longer include RADAR Type Number.

NAVAID (NAV.txt) NAVAID MAGNETIC VARIATION AND RADIAL RESTRICTIONS

    The magnetic variation value for DME only NAVAIDs will report as null 
    (or blank) since the stand alone DME NAVAID does not provide azimuth 
    information.
    (NOTE: DME, VOT AND FM NAVAID TYPES DO NOT HAVE MAG VAR. ANY VALUE IN THIS 
    COLUMN FOR THOSE NAVAID TYPES SHOULD BE IGNORED.) 

    NAVAID radial restrictions are identified by flight inspection and are 
    published as NAVAID remarks. When there are restrictions on stand-alone 
    DME only NAVAIDs, the restrictions reference true north. A note has been 
    added to the NAV_rf.txt format definition explaining the radial remark 
    information, and the use of a "T" designation to indicate "true north" for 
    the radials in a DME only remark. 
    NOTE: STAND-ALONE DME RESTRICTIONS: THERE IS A NEED TO DIFFERENTIATE 
    BETWEEN RESTRICTION RADIALS AT VOR/DMES, VORTAC, AND RESTRICTION RADIALS 
    REFERENCED TO TRUE NORTH AT STAND-ALONE DMES. THE T AFTER THE RADIAL 
    REPRESENTS TRUE NORTH. 
    EX: DME UNUSBL 080T-125T BLW 10000FT)
    
LOCATION IDENTIFIER (LID.txt) CANADIAN DATA

    The LID 3 'CAN' records which contain location identifiers of Canadian
    customs points of entry, airports, meteorological stations and navigational 
    aids are no longer included in the LID.txt subscriber file starting 
    with the November 3, 2022 AIRAC cycle. 

    Refer to current Canadian charts and flight information publications for 
    information within Canadian airspace.
                      
ILS (ILS.txt) PUBLISHED DISTANCES SCRUB

    The ILS subscriber file publishes many distance or measurements of 
    components relative to various positions on the runway. This is in 
    addition to actual coordinate position data. These distances were 
    originally added to support FAA Flight Inspection, who no longer use this 
    data from NASR. 
    
    Effective with the April 20, 2023 AIRAC cycle, these distances are no 
    longer maintained in NASR. The format of the ILS.txt file has not 
    changed, but the attributes in these columns are nulled. Coordinates 
    and elevation of the equipment remains.

    Specific attributes that are now nulled:
        Localizer 
        o Dist From AER
        o Dist From Centerline
        o Dir From Centerline
        o Dist From Rwy Stop
        o Dir From Rwy Stop
        o Code indicating source of distance information
        o Course Width
        o Course Width at Threshold

        Glide Slope
        o Dist From AER
        o Dist From Centerline
        o Dir From Centerline
        o Rwy Elev Adjacent to GS
        o Code indicating source of distance information

        DME
        o Dist From AER
        o Dist From Centerline
        o Dir From Centerline
        o Dist From Runway Stop
        o Code indicating source of distance information

        Inner/Middle/Outer Marker
        o Dist From AER
        o Dist From Centerline
        o Dir From Centerline
        o Code indicating source of distance information
    
    The format of the ILS.txt file will not change, but the attributes in 
    these columns will be nulled. 

NEW CSV FORMAT SUBSCRIBER PRODUCTS FOR ASSESSMENT 

    There have been requests from users internal and external for an 
    alternative to the flat text fixed length legacy subscriber files. The 
    comma delimited CSV files documented here are an attempt to meet that need. 

    A full complement of subscriber data coded as CSV is now available. 
    All data contained within legacy txt subscriber files are now available 
    in CSV format.

    There is a DATA LAYOUT document and CSV DATA STRUCTURE file for each  
    resource grouping which gives more in-depth detail. See the Data Layout  
    Document and CSV Data Structure file for further information on what data   
    (including data types, max length, how displayed and organized) is contained
    in each. 
    
    There is also a CSV_Readme.doc file specific for the new CSV 
    products. It highlights latest updates to these products, based on 
    feedback and usage analysis, along with organization and presentation 
    differences from the legacy .txt subscriber files. 
    
    Current CSV products available include:
    
        AERONAUTICAL BOUNDARY SEGMENTS CSV - ARB_*.csv
        AIR TRAFFIC CONTROL COMM CSV - ATC_*.csv
        AIRPORT CSV - APT_*.csv
        AIRSPACE FIXES CSV - FIX_*.csv
        AIRWAY CSC - AWY_*.csv
        ASOS/AWOS CSV - AWOS.csv
        CLASS AIRSPACE CSV - CLS_ARSP.csv
        CODED DEPARTURE ROUTES CSV - CDR.csv
        COMMUNICATIONS OUTLET FACILITIES - COM.csv
        DEPARTURE PROCEDURE CSV - DP_*.csv
        FLIGHT SERVICE STATIONS - FSS_*.csv
        FREQUENCY CSV - FRQ.csv 
        HOLDING PATTERN CSV - HPF_*.csv
        INSTRUMENT LANDING SYSTEM CSV - ILS_*.csv
        LOCATION IDENTIFIERS CSV - LID.csv
        MILITARY OPERATIONS CSV - MIL_OPS.csv
        MILITARY TRAINING ROUTE CSV - MTR_*.csv
        MISCELLANEOUS ACTIVITY AREA CSV - MAA_*.csv
        NAVIGATION AID CSV - NAV_*.csv
        PARACHUTE JUMP AREA CSV - PJA_*.csv
        PREFERRED ROUTE CSV - PFR_*.csv
        RADAR CSV - RDR.csv
        STANDARD TERMINAL ARRIVAL CSV - STAR_*.csv
        WEATHER REPORTING LOCATIONS CSV - WXL_*.csv

AIXM SUBSCRIBER FILES ARE BEING PRODUCED: 

    AIXM 5.1 versions of the Navigation Aid, Airport, ASOS/AWOS, and Airway 
    subscriber files are now produced. These products can be found in the 
    "AIXM Data" section of the  NASR Subscription listing.

    The XML schema definition and FAA extensions are placed in a folder named 
    AIXM\AIXM_5.1\AIXM

    "Frequently asked questions" documents are placed in a folder named 
    AIXM\AIXM_5.1\FAQs

    Mappings of data attributes from the .txt file to the AIXM products are 
    placed in a folder named AIXM\AIXM_5.1\mappings

    The actual data files are zipped and placed in a folder named 
    AIXM\AIXM_5.1\XML-Subscriber-Files 

    NAVAID_AIXM
    The AIXM5.1 Navigation Aid subscriber file contains data also published in 
    both the NAV.txt and ILS.txt legacy subscriber files. Both the legacy 
    NAV.txt and ILS.txt products and the new AIXM product will be produced 
    concurrently.

    APT_AIXM
    The AIXM5.1 Airport subscriber file contains the data also produced in the 
    legacy APT.txt subscriber file. Both products are produced in parallel. An 
    updated Airport_DataTypes.xsd file is included in the \extension folder 
    reference documents.

    AWOS_AIXM
    The AIXM5.1 ASOS/AWOS subscriber file contains the data also produced in 
    the legacy AWOS.txt subscriber file. Both products are produced in 
    parallel.

    AWY_AIXM
    The AIXM5.1 AIRWAY subscriber file contains the data also produced in the 
    legacy AWY.txt subscriber file. Both products are produced in parallel. An 
    updated Airway_DataTypes.xsd file is included in the \extension folder 
    reference documents.
    
SPECIAL ACTIVITY AIRSPACE (SAA) 
   
    An AIXM subscriber product called Special Activity Airspace (SAA), 
    containing data for all operational Special Use Area (SUA) and 16 National 
    Security Areas is produced. It is an XML product based on Aeronautical 
    Information Exchange Model version 5.0 (AIXM5). Information on AIXM can be 
    found at http://www.aixm.aero.

    The latest XML schema definition files for the SAA subscriber product 
    can be found within the download.

    The AIXM SAA product can be found in the "AIXM Data" section of the NASR 
    Subscription listing. The subscriber data is zipped with the schema 
    information, inside a zip file named "SaaSubscriberFile.zip". 

Other Notes:

FOREIGN DATA

    These subscriber files contain limited information on non-US resources, 
    primarily for context. These should not be considered official source. 
    Refer to current Canadian charts and flight information publications for 
    information within Canadian airspace.

REMINDER: 

All of the subscriber files are available free of charge from the 
Aeronautical Data/NFDC website located at 
https://www.faa.gov/air_traffic/flight_info/aeronav/aero_data/NASR_Subscription/. 
It is not necessary to register in order to access or download the files. 
However, in order to receive email alerts when the new subscriber set becomes 
available, users must register at 
https://nfdc.faa.gov/nfdcApps/controllers/PublicSecurity/register 
There is no cost to register. Users can select all or individual files to 
download. 


Your comments or suggestions can be directed to Aeronautical Information 
Services at the following contact points:

    Telephone:  1-800-638-8972
                 
    email: 9-AMC-Aerochart@faa.gov 







History:

ARTCC FACILITIES (AFF.txt) RADAR RECORDS

    The AFF1 record has contained basic information on ARTCC associated 
    facilities, including the base ARTCC, CERAP, RCAG, and RADAR sites 
    (ARSR and SECRA). The RADAR site information was minimal, essentially site 
    name, state, and association to one or more ARTCCs. This information will 
    no longer be maintained in NASR. 
    
    Effective with the 29 December 2022 cycle, AFF1 records for ARSR and SECRA 
    sites are no longer included. 

