Any antenna mounted atop any structure--including buildings--should be studied by TSI for the possibility of creating an obstruction to air navigation. If an obstacle is added to any other structure (such as an antenna) it could become a hazard. Additionally, for radio transmitters, the FAA will need to study the frequencies to determine if they will conflict with any navigational frequencies.
Antenna on top of Water Tank
Often antennas are added to water tanks, which may or may not have FAA aeronautical study approval. In a situation like this, TSI recommends that both the tank and the antenna have a full aeronautical study completed before construction is started. We previously had a building that exceeded FAA standards and went undetected until a roof-top antenna addition was planned. We completed the building approval as well as an approval on the antenna. In turn, the FAA revised an Instrument Approach Procedure which enhanced safety for all concerned.
