Medium Intensity Obstruction Light
Flashing white or red, or steady red, for taller or more extensive structures.
View DetailsVisual indication of structures that may present an aviation obstacle
Low-intensity obstruction lights are steady-burning red lights that mark less extensive structures at night, typically where the height above surrounding ground is below about 45 m (150 ft). Type A and Type B differ in minimum intensity; selection follows structure height, location, environment and aviation authority criteria.
Low-intensity obstruction lights provide visual indication of structures that may present an aviation obstacle. They are used on buildings, towers, masts, small structures and other installations where the approved aeronautical study requires low-intensity lighting.
Under ICAO Annex 14 both Type A and Type B are fixed (steady-burning) red lights. They are night-time identification lights; day marking, where required, is by paint or markers, and flashing or higher-intensity lighting is covered by the Medium and High Intensity pages.
Precision AGL Solutions supplies low-intensity obstruction lighting for new installations, replacement projects, obstruction-lighting upgrades and aviation safety applications.
The light provides steady-burning red output and may be installed standalone or as one level of a coordinated obstruction-lighting system. Optical, electrical and mechanical configuration are selected to the project.
The final arrangement should be established from the approved aviation lighting assessment, structure characteristics and applicable regulatory requirements.
| Type | Colour & Mode | Minimum Peak Intensity | Typical Use |
|---|---|---|---|
| Low-intensity Type A (ICAO) | Red, fixed (steady) | 10 cd | Less extensive objects below about 45 m |
| Low-intensity Type B (ICAO) | Red, fixed (steady) | 32 cd | Where Type A would be inadequate or earlier warning is needed |
| FAA L-810 | Red, steady-burning | 32.5 cd | FAA-style low-intensity marking of structures |
Values are the ICAO Annex 14 and FAA minimums and are shown for orientation only. Confirm against the edition and authority that apply to your project.
Obstruction-light classifications and operating requirements depend on the applicable aviation authority and the characteristics of the structure.
The required configuration should always be confirmed against the approved project specification and current applicable aviation requirements.
Low-intensity Type C and Type D lights are flashing lights for vehicles and are not covered by this product page.
| Parameter | Typical Specification |
|---|---|
| Light Type | Low-intensity obstruction light |
| Configuration | Type A or Type B, as applicable |
| Light Source | LED or approved source, configuration dependent |
| Light Colour | Aviation red (ICAO Annex 14 Appendix 1 chromaticity) |
| Operation | Steady-burning (fixed) |
| Minimum Intensity | Type A: 10 cd; Type B: 32 cd; FAA L-810: 32.5 cd (confirm against selected model) |
| Power Supply | Configuration dependent |
| Power Consumption | Model dependent |
| Mounting | Structure, pole, mast or project-specific mounting |
| Dimensions | Model dependent |
| Environmental Protection | Outdoor-rated construction, configuration dependent |
| Operating Temperature | Model dependent |
| Cable / Connection | Project-specific electrical interface |
| Control | Standalone or integrated control, where applicable |
Exact luminous intensity, intensity distribution, electrical ratings, dimensions and environmental performance should be confirmed against the selected model and project requirements.
Modern low-intensity obstruction lights can use efficient LED light sources to provide consistent optical output with reduced maintenance requirements.
The optical assembly is designed to provide the required visibility from relevant viewing directions while maintaining the characteristics required by the applicable classification.
For projects with specific photometric requirements, Precision AGL Solutions can provide product documentation and technical data for engineering review.
Low-intensity Type A and Type B lights are fixed lights and should not flash. A flashing red light, for example on medium-intensity Type B, is a different product category.
Where a structure needs flashing or higher-intensity lighting, select from the Medium or High Intensity obstruction light pages and do not mix lighting types on one level without the approved lighting plan.
Mounting hardware should provide stable positioning and maintain the required optical orientation throughout the operating life of the installation.
Project-specific brackets, adapters or fixing arrangements can be considered where the standard mounting interface does not directly match the structure.
The obstruction light can be selected to suit the available electrical supply and the control arrangement specified for the project.
The final electrical configuration should be coordinated with the obstruction-lighting control system and site power infrastructure.
Depending on the project, additional control or monitoring equipment may provide status indication, fault reporting or centralized supervision.
Correct installation is essential to maintain the intended visibility and reliability of obstruction lighting.
Lights should be installed so that structural elements do not unnecessarily obstruct the intended optical coverage. The top light should be as close to the highest point as practicable, with intermediate levels arranged as required by the approved lighting plan.
The selected enclosure, sealing and materials should be appropriate for the site environment.
For severe environmental locations, material selection and corrosion protection should be reviewed during project engineering.
Where photometric verification is required, measurements should use appropriate calibrated equipment and follow the applicable project procedure.
Intervals should be established according to the installation environment, manufacturer recommendations and applicable airport maintenance procedures.
| Condition | Possible Cause | Recommended Check |
|---|---|---|
| Light not operating | Loss of power or control fault | Check supply, protection and control circuit |
| Reduced visibility | Dirty optical window or optical degradation | Inspect and clean optical surface |
| Incorrect operation | Control or configuration issue | Verify operating mode and control settings |
| Intermittent operation | Electrical connection or supply issue | Inspect terminals, connectors and cable |
| Light flickers or flashes unexpectedly | Loose connection, supply fault or wrong configuration | Check terminals, supply stability and the configured operating mode |
| Moisture inside enclosure | Seal or cable-entry problem | Inspect enclosure and sealing system |
| Mechanical movement | Loose mounting | Inspect and secure mounting hardware |
Low-intensity obstruction lights can be used for replacement and retrofit where existing equipment requires modernization, improved reliability or continued support.
A replacement should not be selected solely by physical dimensions. The optical and operational requirements of the approved obstruction-lighting arrangement must also be maintained.
This allows the light to be selected according to the complete installation rather than as a standalone component.
Use the edition current at the time of your project.
Obstruction-lighting requirements vary according to jurisdiction, structure type, location and aviation authority.
The product and installation should be reviewed against the applicable aviation obstruction-lighting requirements, approved project documentation and current authority requirements.
Where a project is subject to a specific national aviation regulation, engineering specification or airport standard, those requirements should take precedence during final product selection.
Precision AGL Solutions provides aviation lighting equipment for airport, airfield and aviation-infrastructure projects. Our approach supports both individual equipment supply and coordinated project requirements, including:
Low-intensity obstruction lights are steady-burning red lights that mark less extensive structures at night, typically where the height above surrounding ground is below about 45 m (150 ft). They are used on buildings, towers, masts, small structures and other installations where the approved aeronautical study requires low-intensity lighting. They are night-time identification lights, and any day marking is by paint or markers.
Typical uses are buildings and rooftop structures, communication and transmission towers, antenna and telecommunications masts, utility and infrastructure structures, small towers and poles, industrial structures, and temporary or permanent aviation-obstruction installations. They can be installed standalone or as one level of a coordinated obstruction-lighting system, and the final arrangement should come from the approved aviation lighting assessment and applicable regulatory requirements.
Under ICAO Annex 14 both are fixed (steady-burning) red lights and differ in minimum peak intensity: Type A is 10 cd and Type B is 32 cd. Type A is for less extensive objects below about 45 m, while Type B is used where Type A would be inadequate or an earlier warning is needed. The FAA L-810 steady-burning red light has a 32.5 cd minimum. These are minimums for orientation, so confirm them against the edition and authority that apply.
No. They are fixed lights and should not flash. A flashing red light, for example on medium-intensity Type B, is a different product category, and low-intensity Type C and Type D lights are flashing lights for vehicles and are not covered here. Where a structure needs flashing or higher-intensity lighting, select from the medium or high intensity pages and do not mix lighting types on one level without the approved lighting plan.
The choice follows structure height and extent, location and surroundings, the required minimum intensity, the need for earlier special warning, the number and location of lighting levels, visibility from all directions and the applicable obstruction-lighting criteria. Obstruction-light classifications depend on the aviation authority and the structure, so confirm the configuration against the approved project specification.
Follow the approved obstruction-lighting layout, including the required lighting levels and the spacing of intermediate levels. The top light should be as close to the highest point as practicable, and the number of lights per level should let the structure be seen from every direction. Install so that structural elements do not unnecessarily obstruct the optical coverage.
The electrical configuration is selected to suit the site supply and control arrangement, covering supply voltage, AC or DC operation, surge protection, cable entry, connector arrangement, local switching, photocell or automatic day/night control, and remote monitoring or alarm interfaces where required. The final configuration should be coordinated with the obstruction-lighting control system and site power infrastructure.
Verify the mounting position and orientation, electrical connections and supply voltage, and confirm steady-burning operation with no flicker or flash. Check the light colour and optical output, photocell or control operation where fitted, and alarm or monitoring interfaces where applicable, then record the results. Where photometric verification is required, use calibrated equipment and follow the project procedure.
Routine work includes cleaning the optical window, checking that red colour and output have not degraded, and inspecting mounting hardware, cable entries and enclosure seals, with periodic functional testing. A light that is not operating points to a supply, protection or control fault, reduced visibility to a dirty optical window, flicker to a loose connection or wrong configuration, and moisture inside the enclosure to a seal or cable-entry problem.
References include ICAO Annex 14 Volume I Chapter 6 (obstacle lighting, Tables 6-1 and 6-2) and Appendix 1 for colours, ICAO Doc 9157 Part 4, FAA AC 70/7460-1 and AC 150/5345-43J (L-810), and DGCA India CAR Section 4 with AAI and NOC conditions. Requirements vary by jurisdiction, structure and authority, and specific national regulations take precedence in final selection.
Provide the structure type, height and location, the applicable aviation authority or project specification, the required Type A or Type B classification, the operating mode and colour, the quantity, the mounting arrangement, the available power supply, the existing control system, the environmental conditions and whether it is a new or replacement installation. For replacements, do not select by physical dimensions alone, because the optical and operational requirements of the approved arrangement must be maintained.
Indian public tenders commonly ask for the documents below. State which ones your tender requires when you send the enquiry, so they are covered in the quotation.
Need to identify the correct obstruction light for a building, tower, mast or other aviation obstacle? Send us the structure height, location, required Type A/B classification, operating mode, power supply and applicable project specification. We can review the application and recommend the appropriate Low Intensity Obstruction Light configuration, including optical characteristics, mounting arrangement and electrical interface.
Request obstruction-lighting selection and technical documentation from Precision AGL Solutions.
Obstruction-lighting classification, intensity, number of levels and installation arrangement are application- and authority-dependent. Exact product parameters should be confirmed against the approved aviation lighting assessment and the current requirements applicable to the project before procurement or installation. Type A and Type B are steady-burning red lights; flashing or white lighting belongs to the medium- and high-intensity categories.
Product availability, configuration, dimensions, electrical characteristics, photometric performance, certifications and compliance status depend on the selected manufacturer and project specification. The technical values published on this page should not be treated as a substitute for the manufacturer's current approved Technical Data Sheet.
Final selection shall be based on the approved project specification, applicable aviation standards, authority requirements, manufacturer documentation and site conditions. Use of this page is also subject to the Legal Notice, Disclaimer & Terms of Use.
Standards and editions referenced on this site are listed on the Standards Reference page.