IFR low altitude chart symbol

6 Answers

1. Best Answer
   
   

   
   

   Kris Kortokrax on Jun 05, 2016

   Download the Aeronautical Chart User’s Guide at this location:

   https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/aero_guide/media/Chart_Users_Guide_12thEd.pdf

   Then do a “Find” for “Facility Locators”.

   You question will then be answered.

   I’d rather teach you to fish, than give you a fish.

   -10 Votes 3 Votes  13 Votes

2. 
   

   
   

   Mark on Jun 05, 2016

   Kris,
   Thanks for the reference.

   Unfortunately, the Chart Users Guide contains no more information explaining the function and content elements of the Facility Locator symbol than does the IFR low altitude enroute chart Legend. The descriptor wording is identical and there appears no further discussion in the Guide.

   In particular, it is not clear to me what the numbers following 3-letter facility designation mean. They do not appear to be distances to the facility from nearby fixes or distance from the fix to from the symbol itself. The utility of this symbol on the chart is remains unclear (how and when and IFR pilot would use this symbol to aid in enroute planning or navigation).

   +1 Votes 1 Votes  0 Votes

3. 
   

   
   

   Kris Kortokrax on Jun 05, 2016

   All it took me was a quick look at a locator and at the information box for the associated VOR to determine that the information contained in the locator symbol is the frequency of the VOR to the left of the 3 letter identifier and the two digit DME channel to the right. You would have no use for the DME channel.

   The legend and the chart user’s guide could be of more help, but this stuff is not rocket science.

   -26 Votes 3 Votes  29 Votes

4. 
   

   
   

   Skyfox on Jun 05, 2016

   The purpose of the facility locators are to provide cross radial information so that for a given intersection/waypoint, you can see the frequency, radial, and ident of a distant VOR that defines that waypoint. The pointy end of the oval frequency locator shape points towards the VOR being identified. On the other end of the oval or below the oval is a line with an arrow pointing to the intersection/waypoint being defined with that cross radial. Inside the oval is the same information found in the navaid information box next to the VOR with the frequency of the VOR, the 3 letter identifier of the VOR, and it’s the corresponding TACAN channel which follows the identifying letters as you specifically asked, not the distance to the VOR (keep reading; more on that below). If the frequency is underlined, that corresponds to the same “no voice” underline under the frequency in the navaid information box next to the VOR itself. And as you already saw in the Aeronautical Chart User’s Guide, cross-hatch shading inside the facility locator indicates it’s out of service at the time of that publication of the chart. The line with the arrow pointing to the intersection includes the radial to be tuned in for identifying that point, plus the DME distance from the VOR which is found inside the big D shape on the arrow.

   For example, go to Skyvector.com and search for SUDDS intersection. Below it is a facility locator box that says, “113.0 OBK 77” with 113.0 underlined. That points towards Northbrook VOR/DME to the south-southwest. The line with arrow pointing to SUDDS says it’s on the 027° radial at 61 DME. When you’re flying V2 to or from Badger VORTAC to the west, if you tune your second VOR to 113.0 for OBK and set it to the 027° radial, when the needle centers (and provided you’re properly on course on V2) you know you’re at SUDDS intersection for your own navigation logging purposes and/or position reporting. If you have DME it should show you’re 61 NM away at that point. And don’t expect to use OBK for any sort of voice receiving purposes.

   To the southeast of SUDDS is PAITN intersection with another facility locator next to it indicating 115.95 for VIO (Victory VOR/DME south of GRR) on the 260° radial is to be used as a cross radial to define PAITN intersection when flying V170.

   See? Nothing to it!

   BTW, I looked in the Instrument Flying Handbook (FAA-H-8083-15B) and the Instrument Procedures Handbook (FAA-H-8083-16A) and neither one seemed to provide any real description of what a facility locator is for. I just had to go by memory of past training and looking at the chart. The chart legend only says, “Facility Locators used in formation of Reporting Points.”

   +18 Votes 18 Votes  0 Votes

5. 
   

   
   

   Mark on Jun 05, 2016

   Thanks – great answers. Makes complete sense now. The DME frequency had me stumped. I see that without the facility locator, the origin of some of the radial crossing arrows to identify a fix might be difficult to locate.

   +2 Votes 2 Votes  0 Votes

6. 
   

   
   

   Adam Linamen on Feb 26, 2023

   The numbers after the station letters are the TACAN channel. Try googling the station and include the numbers for the TACAN channel in the search, and you will see it is the same numbers followed by an additional letter.

   0 Votes 0 Votes  0 Votes