Enroute IFR Chart

5 Answers

1. 
   

   
   

   jeff on Mar 01, 2016

   The answer is on page 54 of the FAA’s Aeronav Chart Users Guide 12th edition. Essentially, on the lower altitudes charts, because there may be VORs with similar frequencies, one of several additional identifiers is added, morse code being one of them. On the high altitude charts, these nav aids are far enough apart that it isnt an issue. The Chart users guide can be downloaded from the FAA’s site and is an excellent reference for any questions about vfr or ifr chart producrs.

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2. 
   

   
   

   Skyfox on Mar 01, 2016

   I have to partly disagree with what Jeff said. To copy and paste from the Aeronautical Chart User’s Guide, page 54:

   On IFR Enroute Charts, information about NAVAIDs is boxed
   as illustrated below. To avoid duplication of data, when two or
   more NAVAIDs in a general area have the same name, the name
   is usually printed only once inside an identification box with the
   frequencies, TACAN channel numbers, identification letters, or
   Morse Code Identifications of the different NAVAIDs are shown
   in appropriate colors.

   What’s illustrated below that paragraph is a copy of the navaid sections of the legend from the high altitude and low altitude IFR charts. What this paragraph is talking about is when, for example, a VOR and an NDB are at the same location with the same name, the navaid information box will have just that name once along with the NDB frequency, the VOR frequency, TACAN information, etc. In such a case it does make sense in the event the various navaids have different morse code identifiers. However, in looking at the IFR Enroute High Altitude charts on Skyvector.com, I can find no VOR identifiers anywhere that have the morse code identifier even when I know there are no other navaids at that point. Take for example Pullman VOR (PMM), a high class VOR. There is nothing else in that location but the VOR, yet its morse code identifier doesn’t appear on the high altitude IFR chart. Similarly, it doesn’t appear on the world high altitude chart. It’s the same for Keeler VOR (ELX) just to its south, which is a low class VOR.

   Sorry to say, in all the places I’ve searched I can find no explanation as to why there are no morse code identifiers in the navaid boxes on high altitude IFR charts.

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3. 
   

   
   

   jeff on Mar 02, 2016

   Skyfox,

   Thats what I get for answering too late at night. Read more carefully does not explain why there are no morse code identifiers on the high altitude charts. You are correct. I stand by my assertion though, that the chart users guide is an excellent reference and I habe been surprised how many students and pilots do not know it exists. Thanks for the more correct response though.

   Jeff

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4. Best Answer
   
   

   
   

   John D Collins on Mar 02, 2016

   High Altitude Enroute charts cover much more territory than the low altitude charts. It takes 36 Low Altitude Enroute charts to cover the same space that it takes for the 12 High Altitude Enroute charts.This makes the spacing between VOR’s much smaller on the physical High Altitude Enroute chart. So the morse code is eliminated to reduce clutter on the High Altitude Enroute Charts, but the High Altitude charts have a Morse code conversion table on the legend. So it is up to the pilot to look up the code if they don’t know Morse code.

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   Dan Chitty on Mar 02, 2016

   Thanks for the feedback to all. Very insightful.

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