The Enforcement Bureau’s Field Offices investigate complaints regarding lighting outages, other deficient lighting and marking of antenna structures that can cause air hazards, and failures to comply with rules governing lighting monitoring, tower registration, and tower recordkeeping. Any person or entity proposing to construct or alter an antenna structure that is more than 200 feet in height, or that may interfere with the approach or departure space of a nearby airport runway, must notify the Federal Aviation Administration (FAA) of proposed construction. The FAA determines whether the antenna structure constitutes a potential hazard and may recommend appropriate painting and lighting for the structure. Section 303(q) of the Communications Act gives the Commission authority to require painting and/or illumination of radio towers in cases where there is a reasonable possibility that an antenna structure may cause a hazard to air navigation. The Commission uses the FAA's recommendation to impose on radio tower owners and certain licensees specific painting and/or lighting requirements, found in Part 17 of the Commission’s rules. To promote safety in aircraft navigation, the Commission requires the owners of antenna structures to register antenna structures that are regulated by the Commission by filing an application for Antenna Structure Registration (ASR) on FCC Form 854 using the ASR System.