28 Jan, 2021
The Federal Aviation Administration has released a new Advisory Circular, AC 70/7460-1M , effective November 16, 2020, which details new rules and regulations for obstruction marking and tower lighting. Consequently, AC 70/7460-1L Change 2 was cancelled with the release of the new circular. Compared to Circular L-Change 2, most changes were minor and do not impact most tower owners, with the bulk of the changes involving new obstruction lighting rules for temporary structures like cranes. However, one change was implemented that does directly affect tower owners: the addition of new infrared specifications for red LED-based obstruction lights, which are now required for new LED lighting system installations. These new infrared specifications help ensure the safety of pilots operating with night vision goggles. Night vision goggles (NVGs) are increasingly being used by pilots to amplify visible light and ensure safety, and many NVGs have filters (notably a Class B filter) designed to reduce the adverse effects of cockpit lighting. These filters can make red LED obstruction lights completely invisible which presents a risk to pilot’s safety. Circular 1M requires that all new LED lighting system installations must feature LED lighting that is compliant with these requirements. Tower owners under older circulars are grandfathered in and do not need to meet these new specifications and can continue to use non-infrared LED lights. However, because there is a risk of a pilot misinterpreting a tower’s height, if a legacy (non-IR) specification, intermediate-level LED light is replaced with one that meets the new IR specifications, then the top-level light or lights must meet the new IR specification. This applies to all towers, even those governed under previous circulars. More information about the IR specifications can be found in our previous blog post . LumenServe℠ can help with your new build, lighting system upgrade or conversion, as our Tower Lighting as a Service® fully conforms to the new FAA standards (AC 70/7460-1M, AC 150/5345-43J and EB 98). Our OEM partner, Dialight, launched its first IR enabled LED product in 2011, almost a decade before FAA regulation cited above became mandatory.