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The FAA's sectional aeronautical charts include some power/transmission lines. How complete is this?

I am specifically interested in using something like ForeFlight for aeronautical charts while hot air ballooning. Is this a fool's errand?

If it is an incomplete reference for power/transmission lines, does anyone know what criteria the FAA uses for inclusion in the charts?

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    $\begingroup$ It is not complete by far. The FAA does maintain an obstacle database, but because it would clutter up the map they use some kind of criteria about when to show them or not. For example there are power transmission lines that run along the road by my house, neither the road nor the transmission lines are shown on the VFR map. I can't seem to find any information on how they decide to show an obstacle or not. $\endgroup$ – Ron Beyer Apr 23 '17 at 2:40
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    $\begingroup$ @RonBeyer Please don't add an answer as a comment $\endgroup$ – J. Hougaard Apr 23 '17 at 9:14
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    $\begingroup$ It isn't an answer though, I don't know the criteria they use to choose whether or not it's on the map. $\endgroup$ – Ron Beyer Apr 23 '17 at 11:27
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    $\begingroup$ In my experience the charts show many/most of the tall high tension power lines, but not the shorter lines. I don't know how complete the data is though. $\endgroup$ – J Walters Apr 23 '17 at 14:09
  • $\begingroup$ Similarly, do not expect that all centenarys are charted. $\endgroup$ – mongo Dec 9 '18 at 1:35
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From the FAA's Chart Users' Guide:

AeroNav Products’ charts are prepared in accordance with specifications of the Interagency Air Cartographic Committee (IACC) and are approved by representatives of the Federal Aviation Administration (FAA) and the Department of Defense (DoD).

Book 2 of the IACC Specifications covers Sectionals and VFR Terminal Charts and provides the following guidance for transmission lines:

3.6.6.3 Telecommunication and Power Transmission Lines (T-Lines)

3.6.6.3.1 Landmark Value

T-Lines, if depicted on charts, are shown primarily for their landmark value. Determination of whether a T-line has landmark value or what constitutes chart congestion are matters of FAA Flight Edit judgment. Flight Edit shall either delete or add T-Lines on the Flight Edit Standard. T-lines with landmark value should be shown in open country and not in congested or built-up areas. Through open country, T-lines should be shown as continuous lines, interrupted only for reasons of cartographic practices. Location of the pylon symbol is dependent upon the length of the T-line; approximately at 1" intervals on a line 3" or less in length, and approximately 2" apart on lines longer than 3".

The transmission lines may also be charted under the rules of section 3.9.8.6 Obstructions.

So, no. T-Lines are not charted exhaustively. They are charted only when they have landmark value or are charted as an obstruction.

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