AIS subscriber files effective date February 23, 2023. Dear Subscribers, For the February 23, 2023 subscriber files, the files incorporate data published in the daily National Flight Data Digest (NFDD) through NFDD 014 dated 01/23/2023. The February 23, 2023 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 DATUM The legacy text subscribe files do not cite a datum for geodetic coordinates. All US coordinates information provided is currently reference NAD 83. 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 2023, this will be the April 20, 2023 effective date. 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 is indicated in the "Mea Dir" column and the "Remarks Text" column in Rec Type RMK. Effective 23 Feb 2023, the direction information will be 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) 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 no longer be allowed and current null values will be modified to "NONE". Effective with the 15 June 2023 cycle, Runway Surface Treatment in the RWY record of the APT.txt subscriber will no longer contain null values. 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 15 June 2023 cycle, TYPE OF RADAR AT THE TOWER fields in the TWR5 records will no longer included RADAR Type Number. 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. 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 naviad 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, meteorlogical stations and navigational aids are no longer included in the LID.txt subscriber file starting with the Novemeber 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 December 29, 2022 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 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 Effective with the April 20, 2023 AIRAC cycle, the Localizer course width and Localizer course width at threshold should also be nulled, pending comment. These lengths will no longer be maintained in NASR. 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. The goal is to have a full complement of subscriber data coded as CSV files by the end of the 2023 calendar year. There is a DATA LAYOUT document for each resource grouping which gives more in-depth detail. See the Data Layout Document for further information on what data (including how it is 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: AIR TRAFFIC CONTROL COMM CSV - ATC_*.csv AIRPORT CSV - APT_*.csv AIRSPACE FIXES CSV - FIX_*.csv ASOS/AWOS CSV - AWOS.csv CLASS AIRSPACE CSV - CLS_ARSP.csv CODED DEPARTURE ROUTES CSV - CDR.csv COMMUNICATIONS OUTLET FACILITIES - COM.csv FREQUENCY CSV - FRQ.csv HOLDING PATTERN CSV - HPF_*.csv INSTRUMENT LANDING SYSTEM CSV - ILS_*.csv MILITARY OPERATIONS CSV - MIL_OPS.csv NAVIGATION AID CSV - NAV_*.csv PREFERRED ROUTE CSV - PFR_*.csv RADAR CSV - RDR.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 subscribe 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 subscribe 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 subscribe 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 in 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 Goodnight Gracie