The Federal Aviation Administration (FAA) released new guidance on obstructions, updating builders and developers on the requirements for marking and lighting any structure that may impact the National Airspace System (NAS), such as tall buildings, energy and electricity infrastructure, and communications towers. Developers should familiarize themselves with the new guidance, which will apply to new construction.

Any person proposing to build (or alter) a structure 200 feet or higher or other structures lower in height and closer to U.S. airports must notify the FAA of the proposed construction at least 45 days in advance.

Once notified of such a project, the FAA reviews the project on a case-by-case basis to determine whether the proposed structure will be a hazard to air navigation. Determinations, once completed, often contain conditions regarding lighting and marking of obstructions, and it is at this stage that the FAA’s new guidance comes into play.

FAA Advisory Circular (AC) 70/7460-1L updates the guidance on the marking and lighting of obstructions for the first time since 2007. The AC’s principal changes include:

• Updating the AC to reflect the previous change in the definition of an obstruction from 500 feet AGL to 499 feet AGL. The FAA says “All structures above 499 feet are considered obstructions and the FAA will continue to conduct an aeronautical study on these types of structures to determine their effect on the navigable airspace and ensure they do not create a hazard.”
• Adding a chapter to provide performance standards for Aircraft Detection Lighting Systems (ADLS). ADLS detects aircraft within a proximity of at least 3 NM horizontal and 1,000 feet vertical and automatically lights obstructions if there are aircraft within that perimeter. This technology allows lights and markings to be activated only when necessary, preventing unnecessary distraction for neighbors. The FAA says that this change is in response to community groups, industry, and the aviation community who wanted clearer guidance on ADLS.
• Specifying new lighting for wind turbines at various heights.
• Implementing standards for voluntary marking of meteorological evaluation towers less than 200 feet AGL to make these towers more noticeable, particularly for low-level agricultural flight operations; and
• Revising lighting and marking standards to reduce the impact on migratory bird populations.

The new AC guidance will impact future construction or alterations to structures (e.g. buildings, energy and electricity infrastructure, and communications towers) as builders will need to comply with these standards to ensure Determinations of No Hazard remain valid, and more importantly, so aircraft can see and avoid structures in their paths.