forgive me if this isn’t quite the place to post this, but i could use help in airspace interpretation. i’m getting ambiguous readings and i'm trying to ensure that i make the proper interpretation as to where i can legitimately fly.
i’m looking to get FAA authorization to fly just inside the Class D airspace of Phoenix Deer Valley airport (DVT). the sectional for DVT shows a ceiling of <4000 feet AGL [-40], but the FAA UAS map at faa.maps.arcgis.com shows a height limit of 300 feet for the quadrangle i wish to fly in (Northwest corner of the Class D boundary).
i used Kittyhawk for request FAA authorization via LAANC and at Step 4 of 4 (within Kittyhawk) i came across bullet 5: “Altitude limits are absolute values . . . shall not be added to any structures”. note Kittyhawk is consistent with the map shown by faa.maps.arcgis.com for the quandrangle in question (300’ limit). [i have an snapshot but this site only prompts for an image at a URL and i don't have a URL: it's a PNG file on the hard drive ]
FAA regs clearly state that one can fly up to 400’ above the top of a structure (say, a tower) but both the faa.maps.arcgis.com map and Kitthawk/LAANC submission process suggest this is not so. they’re essentially saying that if i need to inspect a communications tower that would require me to fly above 300’ i cannot do it. yes? no?