NAVIGATION Data Dictionary
SUMMARY
There are two types of data used for navigation. This article isabout the AIRAC data stored in the /NAVDATA location and consists of sixfiles. One of the files, fmc_ident.txt, is a short file that simplyprovides the data dates. The other files provide airport, runway,navaid, fixes and route definition used by the PMDG FMC. The other typeof data, SIDSTARS, is not discussed in this article.
The location of the files varies with version of MSFS. FS9 uses%/FMCWP/NAVDATA and FSX uses %/PMDG/NAVDATA where % is the rootdirectory for the flight simulator.
The text files containing data used by the PMDG FMC fornavigation are defined in the following sections. Please note thatcolumn position is significant, white space must be space chars(no tab chars)
AIRPORTDATA
Filename: airports.dat
List of airports and airport coordinates listed byascending latitude.
....,....1....,....2....,KCRP 27.770361 -97.501222IIII dd.dddddd ddd.dddddd IIII COL 1-4 ICAO code for airport dd.dddddd COL 5-14 Latitude degrees (-Lat for South) ddd.dddddd COL 15-25 Longitude degrees (-Lon for West) (Note: FAA defines airport location as the centroid of the area defined by the runway edges, and calls it the Airport Reference Point)
NAVAIDDATA
Filename: wpNavAID.txt
List of radio navigation aids containing name, id, type,location andfrequency listed by ascending latitude.
....,....1....,....2....,....3....,....4....,....5....,....6..CORPUS CHRISTI CRP VORD 27.903764 -97.444881115.50HCORPUS CHRISTI ICRP ILSD 27.759597 -97.495508110.30TROCKPORT RKP NDB 28.090569 -97.045544391.00NNNNNNNNNNNNNNNNNNNNNNNNNIIII TTTT dd.dddddd ddd.ddddddfff.ffC NNNN COL 1-24 Facility Name IIII COL 25-28 ID TTTT COL 30-33 Type ILS Insturment Landing System (Localizer) ILSD ILS/DME NDB Nondirectional Beacon NDBM NDB/Locator Middle Marker (LMM) NDBO NDB/Locator Outer Marker (LOM) MARI Unknown - seems to be same as MHW class NDB VOR VHF Omnidirectional Radio VORD VOR/DME (no separate code for VORTAC) dd.dddddd COL 34-43 Latitude (-Lat for South) ddd.dddddd COL 44-54 Longitude ( -Lon for West) fff.ff COL 55-60 Frequency (MHz for ILS/VOR KHz for NDB) See Note Below C Col 61 Class H High Altitude/Long Range N NDB T Terminal/Short RangeNote: If NDB frequency is above 999.99 KHz then thefrequecy field still starts in col 55 and C is col 62, for example:....,....1....,....2....,....3....,....4....,....5....,....6..EREBUNI Y NDBM 40.104053 44.4505831180.00NWhere the frequency above is 1180.00 KHz (1.180 MHz)
RUNWAYDATA
Filename: wpNavAPT.txt
List of runways and instrument approach data containingrunway location,lenght, width, elevation and ILS/LDA course/frequency.
....,....1....,....2....,....3....,....4....,....5....,....6....,....7....,....8CORPUS CHRISTI INTL KCRP13 07508130 27.776997 -97.513328110.3012900043CORPUS CHRISTI INTL KCRP17 06080173 27.779472 -97.496106000.0017300041CORPUS CHRISTI INTL KCRP31 07508310 27.762189 -97.497206110.3030900044CORPUS CHRISTI INTL KCRP35 06080353 27.762925 -97.496031109.5035200040LAMBERT-ST LOUIS INTERNAKSTL12L09003121 38.751781 -90.366294108.9012200528LAMBERT-ST LOUIS INTERNAKSTL12L09003121 38.751781 -90.366294110.1012200528NNNNNNNNNNNNNNNNNNNNNNNNIIIIrrOlllllbbb dd.dddddd ddd.ddddddfff.ffccceeeee NNNN Col 1-24 Airport Name IIII Col 25-28 ICAO-code for airport rr Col 29-30 Runway Number (01-36) O Col 31 Runway Order (L C R) llllll Col 32-36 Runway Length (ft) bbb Col 37-39 Runway Bearing (mag) dd.dddddd Col 41-49 Latitude degrees (-Lat for South Col 40)ddd.dddddd Col 50-60 Longitude degrees (-Lon for West) Decimal at Col 64 fff.ff Col 61-66 ILS/LDA frequency (LOC MHz) ccc Col 67-69 LOC course (mag) eeeee Col 70-74 Runway Elevation (ft MSL) Note: The PMDG FMC will select the first record only if there is more than one record for the runway. This is a problem at locations where there is both an ILS and LDA at same runway, if you want the ILS but the LDA is first (Navigraph is aware of this and usually sorts the ILS first). See KSTL 12L above for example (108.90 MHz is the ILS) Note: The PMDG FMC uses the above information to setup the display, not the MSFS data. This results in variations between scenery and panel displayed information for runway elevation and LOC course.
FIXDATA
Filename: wpNavFIX.txt
List of navigation fixes/waypoints sorted by ascending latitude.
....,....1....,....2....,...3....,....4....,....5.8750W 8750W-87.000000 -50.00000055S11 55S11-55.000000 111.0000000538E 0538E 5.000000 38.0000003883N 3883N 38.000000 -83.00000038N30 38N30 38.000000-130.000000DOWNS DOWNS 38.053928 -86.251583NNNNN NNNNN dd.dddddd dd.dddddd NNNNN Col 1-5 & 25-30 Fix Name dd.dddddd Col 32-40 Latitude degrees (-Lat for South, sign Col 31)ddd.dddddd Col 41-51 Longitude degrees (-Lon for West, decimal always Col 45) Note: The duplicate name fields may be the result how the FAA provides data, where there are many more fixes defined than provide in the airac data. For example, most terminal data is not included. This data includes airway crossing, radar service boundaries, etc.
ROUTEDATA
Filename: wpNavRTE.txtList of airways by sequential fixes sorted alphanumerically.
....,....1....,....2....,....3....,....4....,....5....,....6....,....7....,....8A602G 001 MOGSA 14.688333 -20.211389A602G 002 TITOR 13.000000 -18.000000A602G 003 LUSTI 12.318333 -16.483333J239 001 ATL 33.629069 -84.435069J239 002 WEONE 33.525689 -85.122247J239 003 JAMMR 33.232136 -86.942319Q10 001 ENM 62.784583 -164.487558Q10 002 ULL 63.692311 -170.470025Q10 003 JED 50.647319 20.251206V11 100 ASI -12.760556 -76.606389V11 101 AND -13.714167 -73.377778V11 102 DABUL -13.697778 -72.886667Column position is not significant. Data is provided in the followingsequence separated by one space character: AAAA Airway Name (alphanumeric) nnn Sequence Number (001 - nnn) NNNN Fix Name dd.dddddd Latitude degrees (-Lat for South)ddd.dddddd Longitude degrees (-Lon for West) Note: The FMC uses the wpNavFIX data when you enter a fix name, it uses the wpNavRTE data when you enter a route and checks that the fix from where you start the route is included in the route definition. It then populates the legs information from the route data up to then next fix you enter.Thanks to Dan Downs for contributing this.