According to this from the FAA, they commonly approve flashing lights: http://transition.fcc.gov/mb/policy/dtv/lighting.html http://transition.fcc.gov/mb/polic

According to this from the FAA, they commonly approve flashing lights: http://transition.fcc.gov/mb/policy/dtv/lighting.html http://transition.fcc.gov/mb/policy/dtv/lighting.html And this advisory (PDF, admittedly from the Alaskan office, but I doubt there is much variance), provides for flashing lights on towers: http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/systemops/fs/alaskan/towers/obstruction/media/AC70_7460_1K.pdf http://www.faa.gov/about/office_org/headquarters_offices/ato...