The ExportAixm51 function must export ADHP.Elev_Val.

Workaround

Navigate to C:\Program Files (x86)\ArcGIS\AviationCharting\Desktop10.7\DataExchange\AIXM\Exporter\51

Edit the 51ExportTemplate.xml file to fix the malformed entries for AirportHeliport fieldElevation and fieldElevationAccuracy. Make a backup of the original first.

Search for the following code (lines 31-32):

<aixm:fieldElevation removeIfOnlyAttributes="true" uom="{vertdist_uom}"/>

     <aixm:fieldElevationAccuracy/>

Replace the code above with the following:

 <aixm:fieldElevation removeIfOnlyAttributes="true" uom="{vertdist_uom}">{elev_val}</aixm:fieldElevation>

   <aixm:fieldElevationAccuracy>elevaccuracy_val</aixm:fieldElevationAccuracy>

Steps to Reproduce