Learning IFR Low Altitude Charts

Discussion in 'Flight Following' started by Guy Morton, Jul 30, 2020.

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  1. Guy Morton

    Guy Morton Filing Flight Plan

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    GM
    I am new to the forum and am studying for my IFR and reviewing low altitude charts. This is my first ever question on a forum. Here goes: Why don't the majority of the VOR boxes on my New York IFR Low Altitude chart include service volume class desgnators? (T,L, or H). I see a few designated as terminal, but most omit the designation altogether.
     
  2. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

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    The chart user's guide isn't keeping up with reality I think. (H) was never used. (L) is no longer used. Only T-VORs are depicted (like TEB).
     
  3. Guy Morton

    Guy Morton Filing Flight Plan

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    That is super helpful. Thank you!
     
  4. JScarry

    JScarry Pre-takeoff checklist

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    Here’s my guess at the logic of only including a notation for Terminal VORs on the Low Altitude charts. Same logic applies to only showing High and Low Altitude VORs on High Altitude Charts and only indicating which ones are Low. I refer to these diagrams from the AIM in my explanation.

    VORs.png

    Victor airways are defined with a combination of High and Low Altitude VORs. It doesn’t matter which type of VOR you use. At low altitudes you are guaranteed at least 40 miles of coverage. Terminal VORs are never used to indicate Victor airways but do appear on low altitude charts when they are part of a transition route or a fix that starts an approach. The same is true for an ILS.

    The High Altitude Charts never show Terminal VORs and indicate which ones are Low Altitude VORs because at high altitudes the expected coverage is 130 nm. Since Low Altitude VORs only have a service volume of 40nm knowing which ones are low would be important when doing a changeover.
     
    Last edited: Jul 30, 2020
  5. dmspilot

    dmspilot En-Route

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    Well, if you think about it, it really doesn't make much difference to a user of a LOW enroute chart whether it's an L or H class VOR.
     
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  6. bobmrg

    bobmrg En-Route PoA Supporter

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    Maybe its the Forrest Gump in me, but I have never paid any attention to those designations. If I am receiving a solid signal with a steady needle I am good to go no matter what the chart says. IMHO service volumes are only important when you are taking a written exam.
     
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