Obstruction Lighting Guide: A Comprehensive Overview of FAA and ICAO Requirements

Introduction

Any structure exceeding 200 feet above ground level generally needs to be marked and lit according to FAA and ICAO regulations, designed to keep tall structures visible to pilots in low visibility or at night. Exactly what marking is required depends on more than height alone — weather, terrain, and proximity to airports all play a part. Cooper Crouse-Hinds' Obstruction Lighting Guide is a practical resource for navigating these standards, and this article summarises its key points.

The Fundamentals

Height is only one factor in deciding how a structure gets marked. Red lighting systems require the structure to be painted in alternating bands of aviation orange and white for daytime visibility, since red lights are a nighttime-only measure. White or dual lighting systems remove that painting requirement entirely, relying on the lights themselves for both day and night visibility.

The guide's equipment classifications form the basis of most obstruction lighting systems: L-810 (steady-burning red obstruction light), L-864 (flashing red obstruction light, 20-40 flashes per minute), L-865 (medium intensity flashing white, 40 FPM), L-866 (medium intensity flashing white, 60 FPM), L-856 (high intensity flashing white, 40 FPM), L-857 (high intensity flashing white, 60 FPM), L-864/L-865 (a dual flashing red/medium intensity white combination), and L-885 (red catenary, 60 FPM).

FAA Lighting System Configurations

The FAA defines standard configurations that scale with structure height and lighting type.

Type A (red lighting system) is used on painted towers with red nighttime lights. The number of L-864 flashing beacons and L-810 steady-burning lights increases with height — a structure between 151 and 350 feet (configuration A-1) needs just one L-864 beacon at the top, while a structure between 701 and 1,050 feet (A-3) needs beacons at both the top and midpoint, plus L-810 lights at multiple intermediate levels.

Type C and D (white lighting systems) use white lights day and night, removing the need to paint the tower. Type C uses a high intensity/medium intensity white beacon on any appurtenance over 40 feet tall; Type D uses medium intensity white only. Light levels scale with height too — a 200-350 foot structure (D-1) needs one L-865/L-866 beacon at the top, while a 501-700 foot structure (C-2) needs a beacon at the top plus one at half height.

Type E and F (dual lighting systems) show white during the day and switch to red at night. Type E is a dual red/medium intensity white system; Type F is dual red/high intensity white, with a dual beacon on any appurtenance over 40 feet. A structure between 351 and 500 feet (E-2) needs a dual L-864/L-865 beacon at the top, an L-864 beacon at half height, and L-810 lights at intermediate levels.

Chimneys and stacks follow their own FAA/FCC guidance, with the number of lights per level set by structure diameter: 3 lights per level for diameters up to 20 feet, 4 lights for 21-100 feet, and 6 lights for 100-200 feet. The number and type of lighting levels then follow height-based configurations (A0 through A4), with the lowest level always raised above the height of any adjacent structures.

ICAO Lighting Configurations

ICAO standards follow similar principles but use their own classification scheme.

ICAO red lighting covers painted towers with red nighttime lights, using Medium Intensity Type B (flashing) or Type C (steady) lights alongside low-intensity steady lights, with level spacing capped at 52 metres. A structure between 105 and 208 metres, for example, needs a low- or medium-intensity beacon at the top plus low-intensity lights at mid-level and at the base.

ICAO white lighting uses white lights day and night, typically Medium Intensity Type A (L-865/L-866) beacons at the top and additional levels as height increases; structures over 526 metres also need High Intensity Type A (L-856/L-857) beacons.

ICAO dual lighting shows white by day and red by night, combining Medium Intensity Type A and Type B lights (L-864/L-865) with Low Intensity Type B (L-810) lights across a mix of flashing beacons and steady-burning lights at multiple levels.

LED Technology

The guide highlights LED as the clear modern choice for obstruction lighting — long service life, high brightness, and strong energy efficiency add up to years of low-maintenance, cost-effective operation. Cooper Crouse-Hinds' LED obstruction lights, beacons, and visual signals use solid-state technology in a corrosion-resistant, weather-tight housing built to meet rigorous standards for demanding environments.

This article summarises key concepts from the Cooper Crouse-Hinds "Obstruction Lighting Guide." Related technical documentation is available as a free download from Eaton.