Aviation obstruction lights mark buildings, towers, wind turbines, and other structures that can pose a risk to aircraft, making them visible from miles away and reducing the chance of midair collisions, especially during nighttime or low-visibility conditions. To regulate and standardize these safety measures, the Federal Aviation Administration (FAA) established Part 77, a set of rules that identify and manage obstructions to air navigation. Let’s explore how FAA Part 77 defines airspace obstructions and how obstruction lighting systems help protect pilots and passengers from potential hazards in the sky.
- What Is FAA Part 77 and Why It Matters
- How Obstruction Lighting Works
- FAA Lighting Requirements for Obstruction Marking
- Choose Hali-Brite for FAA-Compliant Obstruction Lighting Solutions
What Is FAA Part 77 and Why It Matters
FAA Part 77 sets the national standards that determine when a structure becomes a potential hazard to aircraft. It establishes the criteria the FAA uses to evaluate whether a tower, building, crane, wind turbine, or any other object, existing or planned, might interfere with safe air navigation. These standards are designed to maintain safe clearances in the airspace pilots rely on during takeoff, landing, and en route flight.
Under Part 77, a structure can be considered an obstruction if it exceeds certain height thresholds, even if it is far from an airport. For example, any object rising 499 feet above ground level automatically qualifies as a potential obstruction. Closer to airports, the threshold is even lower. Any structure that reaches 200 feet above ground level or higher within three nautical miles of an airport with a long runway meets the criteria.
Furthermore, Part 77 accounts for more specialized airspace areas, such as instrument approach routes, departure paths, circling approaches, and federal airways. If a structure intrudes into any of these protected surfaces or reduces the minimum required obstacle clearance for a pilot, the FAA considers it an obstruction. Mobile structures can be evaluated as hazards if their normal operating heights interfere with navigable airspace.
Why do all of these matter? Such evaluations help pilots maintain safe distances from tall objects during all phases of flight. When a structure meets the criteria of an obstruction under Part 77, the FAA requires mitigation measures, such as obstruction lighting systems, marking, or other visibility enhancements. These lights ensure that pilots can easily see the structure from a distance, especially at night or in poor visibility.
How Obstruction Lighting Works
Obstruction lighting systems mark structures visible to pilots from a safe distance, both day and night. These lights use specific intensities, colors, and flash patterns so pilots can instantly recognize them as warnings. Steady-burning red lights are typically used on shorter structures, such as buildings, towers, or smaller obstructions near airports, where pilots fly at lower altitudes. The light remains constant, so it’s easy for pilots to identify the location of the structure. Flashing lights, on the other hand, mark taller or more isolated structures. These systems emit high-intensity or medium-intensity flashes at specific intervals.
During the daytime, white flashing lights provide a strong contrast against the sky. At night, red beacons or steady-burning red lamps prevent glare and help pilots readily pinpoint the obstruction. The FAA regulates flash rates so lights are noticeable but not disorienting. Medium- and high-intensity lighting systems automatically reduce brightness during nighttime to prevent light pollution. These coordinated features ensure that obstruction lighting consistently communicates danger, helping pilots maintain situational awareness, avoid midair collisions, and safely navigate around obstacles in all lighting conditions.
FAA Lighting Requirements for Obstruction Marking
The FAA outlines standards for obstruction marking and lighting to ensure consistent safety across the airspace. These standards detail the color, flash rate, intensity, and placement of lights used on different structures, depending on their height and location.
Color and Type
There are three main types of aviation obstruction lighting systems:
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- Aviation Red Lighting
Aviation red obstruction lighting systems feature either steady-burning or flashing red lights. Tall towers are often equipped with flashing red beacons, while smaller structures closer to airports use steady-burning red lights to improve visibility without overwhelming surrounding lighting.
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- Medium-Intensity Flashing White Lighting
Designed for day and twilight visibility, medium-intensity flashing white lighting systems automatically reduce brightness at night. These lights are typically installed on structures up to 700 feet above ground level (AGL) with no additional painting or marking required.
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- High-Intensity Flashing White Lighting
High-intensity flashing white lighting systems are visible both day and night, automatically adjusting their intensity based on ambient lighting conditions. These lights are often used on very tall structures above 700 feet AGL, wind farms, and other tall obstructions in rural airports or remote areas where marking paint might not be visible.
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- Dual Lighting Systems
Dual lighting configuration combines red lights for nighttime with medium- or high-intensity white lights for daytime and twilight. The system automatically switches between lighting modes to ensure continuous visibility while reducing energy use and light pollution.
Flash Rates and Intensity
Flashing lights on a structure must operate in sync, meaning all lights flash simultaneously to maintain a clear and consistent signal for pilots. The flash rate and brightness are standardized so that pilots can easily identify obstruction lights and distinguish them from other sources of illumination. If a flashing circuit fails, the system must default to steady-burning mode to maintain continuous visibility.
Placement
The FAA specifies that the number of light levels depends on the total height of the structure. Each level should be spaced so that at least one light is visible to a pilot approaching from any direction. For very tall structures, such as communication towers, lights are installed at multiple levels, usually at the top and at evenly spaced intervals down the height of the structure.
Choose Hali-Brite for FAA-Compliant Obstruction Lighting Solutions
When you need aviation obstruction lights that meet or exceed FAA standards, Hali-Brite provides the solutions you can trust. Our obstruction lighting products feature energy-efficient LED systems that deliver reliable visibility in all conditions while minimizing maintenance needs. Looking for a sustainable option? We offer solar-powered models that combine performance with energy savings, ideal for remote sites or environmentally conscious operations. Reach out today at (218) 454-095 or here to learn more about our airport lighting systems.