Medium Intensity Obstruction Light
For structures requiring medium-intensity aviation obstacle marking.
View Details Obstruction & Identification Lighting
High Intensity Obstruction Light (Type A/B)
High conspicuity for major aviation obstacles in the surrounding airspace
High-intensity obstruction lighting is used for structures requiring a high level of conspicuity for aircraft in the surrounding airspace, such as very tall towers, masts and other elevated structures. Selection is based on structure height, location, airspace, optical performance, operating mode and aviation authority requirements.
Supplied by Precision AGL Solutions
Product Overview
High Intensity Obstruction Light (Type A/B)
What It Is
The High Intensity Obstruction Light (Type A/B) provides a high level of visual conspicuity for structures that require enhanced aviation obstacle identification.
For tall structures, a complete installation may consist of multiple lights at defined elevations, making the structure identifiable from relevant aircraft viewing directions while maintaining the required optical characteristics.
Depending on configuration, Type A or Type B may be selected, with final intensity, colour, flash characteristics and operating arrangement determined by the project requirements.
Depending on Configuration, the System Can Incorporate
- High-intensity optical output
- Defined aviation colour
- Flashing operation
- Multi-level installation
- Flash synchronization
- Automatic control
- Status monitoring
- Remote alarm interfaces
Precision AGL Solutions supplies these lights for new installations, major infrastructure projects, replacement systems and obstacle-marking applications.
Applications
Where High-Intensity Lights Are Used
Very tall towersVery tall communication towers.
Antenna mastsTelecommunications and antenna masts.
Wire-support towersTowers carrying overhead wires or cables across rivers, valleys and similar spans (typically Type B).
Industrial structuresTall industrial structures.
Elevated infrastructureLarge elevated infrastructure.
Significant obstaclesSignificant aviation obstacles.
Near airportsStructures near airports or controlled airspace.
High-riseHigh-rise or exceptionally tall structures where applicable.
New installationsNew obstruction-lighting installations.
Replacement & modernizationReplacement and modernization projects.
The final lighting arrangement should be established through the applicable aviation obstruction-lighting assessment and approved project documentation.
Type A / Type B Configuration
Classification Is Application-Specific
The Configuration May Depend On
- Structure height
- Structure location
- Surrounding airspace
- Aviation authority requirements
- Day/night operating conditions
- Required conspicuity
- Required luminous intensity
- Flash characteristics
- Lighting-level arrangement
- Environmental conditions
Confirm from the Approved Design
ICAO Annex 14 Chapter 6 uses Type A where an object stands more than 150 m above the surrounding ground and an aeronautical study shows high-intensity lights are essential for recognising it by day. It uses Type B for towers supporting overhead wires or cables where a study shows they are essential for recognising the wires. The classification is still application-specific.
The final classification should be confirmed from the approved aviation obstruction-lighting design rather than selected solely from the product category.
Key Features
What the Product Category Offers
- High-intensity aviation obstruction lighting
- Type A or Type B configurations, as applicable
- Designed for tall structures and major aviation obstacles
- High-visibility optical output
- Flashing operation where specified
- LED or approved high-performance light-source configurations
- Multi-level structure installation
- Flash synchronization options
- Automatic control options
- Local and remote monitoring options
- Structure-specific mounting arrangements
- Outdoor environmental construction
- Suitable for new and retrofit installations
Typical Technical Data
Confirm Parameters Against the Selected Configuration
| Parameter | Typical Specification |
|---|---|
| Light Type | High-intensity obstruction light |
| Configuration | Type A / Type B, as applicable |
| Light Source | LED or approved source, configuration dependent |
| Colour | White (flashing) |
| Intensity | Typical ICAO effective intensity: Type A 200,000 cd by day, 20,000 cd at twilight, 2,000 cd at night; Type B 100,000 / 20,000 / 2,000 cd. Confirm against the applicable edition. |
| Operation | Flashing or project-specified operation |
| Flash Characteristics | ICAO: 40 to 60 flashes per minute (FAA L-856: 40 per minute). Type A flash together; Type B flash in sequence (middle, top, bottom). Confirm against the applicable edition. |
| Power Supply | Model dependent |
| Power Consumption | Model dependent |
| Monitoring | Local and/or remote, where specified |
| Mounting | Tower, mast, structural or project-specific |
| Dimensions | Model dependent |
| Environmental Protection | Outdoor-rated construction, configuration dependent |
| Operating Temperature | Model dependent |
| Cable / Connection | Project-specific interface |
Exact intensity, flash timing, colour characteristics, electrical ratings, dimensions and environmental performance should be confirmed against the selected product configuration.
Optical Performance
Identification over Significant Distances
The Optical System May Provide
- High luminous intensity
- Defined aviation colour
- Controlled horizontal distribution
- Controlled vertical distribution
- High visual conspicuity
- Consistent optical performance
- Flashing output according to the selected classification
Demanding Conditions
High-intensity lights are designed to provide enhanced visual identification over significant distances and under demanding operating conditions.
For tall structures, optical performance should be considered together with the structure geometry and the required elevation of each lighting level.
Flash Characteristics
Confirmed from Project and Aviation Requirements
Defined Flash Characteristics May Include
- Flash duration
- Flash interval
- Repetition rate
- On/off timing
- Synchronization
- Operating sequence
Where Specified
High-intensity obstruction lighting commonly uses flashing operation where specified by the applicable aviation configuration.
The exact flash characteristic must be confirmed from the applicable project and aviation requirements.
Where several lights are installed on the same structure, synchronization may be required to maintain a coordinated visual signal; Type A lights on one structure flash simultaneously. Type B lights on a tower supporting overhead wires or cables flash in sequence (middle light first, then top, then bottom), so the controller must support the correct mode.
Multi-Level Installation
Lights at Defined Elevations
Upper-Level LightsHighest lighting level
Intermediate-Level LightsMid-structure levels
Lower-Level LightsLower lighting levels
ControllerFlash, sync and day/night control
Monitoring SystemStatus, faults and alarms
Lighting Levels Should Account For
- Structural geometry
- Changes in elevation
- Platforms and equipment
- Antenna assemblies
- Structural obstruction
- Required horizontal coverage
- Required vertical coverage
Approved Design
Very tall structures may require multiple obstruction-lighting levels. The quantity and position of lights depend on the approved obstruction-lighting design.
ICAO calls for intermediate levels to be spaced as equally as practicable, normally not more than about 105 m apart (confirm in the current edition). The final arrangement should be established through the approved aviation lighting assessment.
Flash Synchronization
Coordinated Flashing Across the Structure
A System May Incorporate
- Local synchronization
- Central timing control
- Controller-based synchronization
- GPS or other timing references where specified
- Fault detection
- Remote status monitoring
Architecture
Where multiple high-intensity lights are installed, synchronization can provide coordinated flashing across the structure.
The synchronization architecture should be selected according to the project control philosophy and applicable requirements. Type B wire-support towers need sequential flashing rather than simultaneous flashing.
Monitoring & Fault Detection
Improved Availability and Maintenance Response
Monitoring May Include
- Individual light status
- Controller status
- Power status
- Flash operation
- Communication status
- System fault indication
- Remote alarm output
Integration
Monitoring can be integrated with a site SCADA, building-management or airport infrastructure system where compatible interfaces are required.
Automatic Control
Operating Modes by Condition or Time of Day
Control Functions Can Include
- Automatic day / twilight / night intensity switching (photocell)
- Photocell control
- Flash control
- Synchronization
- System enable/disable
- Fault reporting
- Remote status indication
Mixed Intensities
Where multiple obstruction-lighting intensities are installed together, the controller should coordinate the equipment according to the approved operating sequence.
Electrical Configuration
Supply and Protection for the Installation
Project Considerations
- Supply voltage
- AC/DC configuration
- Power consumption
- Circuit protection
- Surge protection
- Lightning protection
- Cable routing
- Connector arrangement
- Earthing
- Control interfaces
- Monitoring interfaces
Coordination
The electrical installation should be coordinated with the structure's power infrastructure and applicable electrical requirements.
Mounting Arrangements
Towers, Masts, Platforms and Elevated Structures
Typical Mounting Arrangements
- Tower platforms
- Mast brackets
- Structural steelwork
- Equipment platforms
- Rooftop structures
- Dedicated obstruction-light mounting assemblies
Wind, Vibration and Access
Mounting systems should provide secure mechanical support and maintain the required optical orientation under wind and vibration.
The installation should also provide suitable access for inspection and maintenance.
Environmental Performance
Exposed-Structure Conditions
Conditions May Include
- High wind loading
- Rain and moisture
- Dust
- Solar radiation
- Temperature variation
- Vibration
- Ice or severe weather where applicable
- Coastal exposure
- Industrial contamination
Materials
The enclosure, optical window, fasteners and mounting materials should be selected according to the environmental conditions at the installation site.
For severe or corrosive environments, appropriate corrosion-resistant construction and protective finishes should be considered.
Installation Considerations
Confirm Before Installation
The Project Team Should Confirm
- Structure height
- Approved Type A/B classification
- Lighting levels
- Light positions
- Optical orientation
- Mounting design
- Cable routes
- Electrical supply
- Control architecture
- Synchronization requirements
- Monitoring requirements
- Lightning and surge protection
- Maintenance access
Approved Layout
The installation should follow the approved obstruction-lighting layout and applicable aviation requirements.
Commissioning
Verify the Complete System Against the Approved Design
- Inspect mounting and structural fixing
- Verify light orientation
- Check electrical connections
- Confirm supply voltage and protection
- Test light operation
- Verify colour and optical output
- Confirm flash characteristics
- Verify synchronization between lights
- Test automatic control functions
- Test monitoring and alarm outputs
- Inspect cable routing and weather sealing
- Record commissioning results
Where required, photometric verification should be performed using suitable calibrated measurement equipment and the applicable verification procedure.
Maintenance
Periodic Inspection for Reliability and Visibility
Maintenance Activities May Include
- Visual inspection of lights
- Cleaning optical surfaces
- Checking mounting hardware
- Inspecting cable entries
- Checking electrical connections
- Testing flash operation
- Checking synchronization
- Verifying monitoring signals
- Inspecting surge protection
- Checking enclosure integrity
- Replacing damaged components
Intervals
Maintenance intervals should be established according to the installation environment, manufacturer recommendations and applicable site procedures.
Isolate and lock off the supply before servicing, as some units hold stored energy after switch-off. Work at height only under the site permit-to-work and fall-protection procedures.
Troubleshooting
Condition, Cause and Recommended Check
| Condition | Possible Cause | Recommended Check |
|---|---|---|
| Light not operating | Power or control failure | Check supply, protection and controller |
| Reduced visibility | Dirty or damaged optical window | Inspect and clean optical surface |
| Flashing incorrect | Controller or configuration issue | Verify flash configuration |
| Lights out of synchronization | Timing or communication fault | Check synchronization system |
| Monitoring alarm | Light, power or communication fault | Review controller and status information |
| Intermittent operation | Supply or connection issue | Inspect cables and terminals |
| Moisture inside enclosure | Seal or cable-entry problem | Inspect enclosure and sealing |
| Light movement | Loose mounting | Inspect structural fixing and brackets |
A failed obstruction light is an aviation safety matter. Report it promptly to the aviation authority or NOTAM originator under the airport and authority procedure.
Replacement & Retrofit
Modernizing Legacy Systems
Retrofit Evaluation Should Consider
- Existing obstruction-light classification
- Existing light positions
- Structure geometry
- Required intensity
- Flash characteristics
- Supply voltage
- Existing control equipment
- Synchronization method
- Monitoring interfaces
- Cable arrangement
- Current aviation requirements
Not by Dimensions Alone
High-intensity lights can modernize existing systems where legacy equipment requires replacement, improved reliability or updated control and monitoring capabilities.
A replacement should be selected on the complete optical, electrical and operational requirements rather than physical dimensions alone.
Procurement Checklist
Information to Provide for an Assessment
- Structure type
- Overall structure height
- Structure location
- Applicable aviation authority
- Type A or Type B requirement
- Required light colour
- Required intensity
- Flashing requirements
- Number of lighting levels
- Quantity of lights
- Available power supply
- Existing control system
- Synchronization requirements
- Monitoring requirements
- Mounting arrangement
- Environmental conditions
- New installation or replacement status
This allows the configuration to be evaluated as part of the complete structure rather than as an individual light.
Standards & References
Confirm Applicable Requirements
Jurisdiction-Dependent
Requirements vary according to jurisdiction, structure characteristics, location and aviation authority.
Equipment and installation should be reviewed against the applicable aviation obstruction-lighting requirements, approved project documentation and current authority criteria.
Specific Regulations
Where the installation is governed by a national aviation regulation, airport standard or specific engineering specification, those requirements should be confirmed during final product selection.
Reference documents: ICAO Annex 14 Vol. I Chapter 6 and Doc 9157 Part 4; FAA AC 70/7460-1N and AC 150/5345-43J (obstruction lighting equipment, including L-856 high-intensity flashing white); DGCA India CAR Section 4 and the airport NOC conditions. Near an aerodrome, an aeronautical study should decide whether night intensity needs reducing to avoid dazzling pilots. Verify the current edition of each.
Documentation
Depending on the Selected Configuration
- Product datasheet
- Photometric information
- Electrical specifications
- Mounting drawings
- Installation instructions
- Control-system documentation
- Synchronization information
- Monitoring and alarm details
- Wiring diagrams
- Maintenance instructions
- Compliance documentation, where applicable
Why Precision AGL Solutions
Dependable Obstacle Identification
We supply aviation lighting equipment for major infrastructure, airport, tower and airspace-related projects. Our high-intensity obstruction-lighting solutions can support:
- Very tall structures
- Communication and transmission towers
- Major infrastructure projects
- New obstruction-lighting systems
- Legacy-system replacement
- Multi-level tower lighting
- Synchronized flashing systems
- Remote monitoring and alarm integration
- Project-specific mounting and electrical configurations
- Technical selection and documentation
FAQ
High Intensity Obstruction Light (Type A/B) — Frequently Asked Questions
What is a high intensity obstruction light (Type A/B)?
It is an aviation obstruction light that provides a high level of visual conspicuity for structures that need enhanced obstacle identification. For tall structures a complete installation may consist of multiple lights at defined elevations. Type A or Type B may be selected depending on configuration, with final intensity, colour, flash characteristics and operating arrangement determined by the project requirements.
When is Type A used and when is Type B used?
ICAO Annex 14 Chapter 6 uses Type A where an object stands more than 150 m above the surrounding ground and an aeronautical study shows high-intensity lights are essential for recognising it by day. It uses Type B for towers supporting overhead wires or cables where a study shows they are essential for recognising the wires. The classification is still application-specific and should be confirmed from the approved obstruction-lighting design rather than selected from the product category.
What intensity and flash rate do these lights have?
The light is white and flashing. Typical ICAO effective intensity is 200,000 cd by day, 20,000 cd at twilight and 2,000 cd at night for Type A, and 100,000 / 20,000 / 2,000 cd for Type B. ICAO flash rate is 40 to 60 flashes per minute (FAA L-856: 40 per minute). Confirm all values against the applicable edition.
How do lights on the same structure flash?
Type A lights on one structure flash together, while Type B lights on a tower supporting overhead wires or cables flash in sequence (middle light first, then top, then bottom), so the controller must support the correct mode. Where several lights are installed, synchronization can be provided by local synchronization, central timing control, controller-based synchronization, or GPS or other timing references where specified.
How many lighting levels does a tall structure need?
Very tall structures may require multiple obstruction-lighting levels, and the quantity and position of lights depend on the approved obstruction-lighting design. ICAO calls for intermediate levels to be spaced as equally as practicable, normally not more than about 105 m apart (confirm in the current edition). The final arrangement should be established through the approved aviation lighting assessment.
What monitoring and automatic control are available?
Monitoring may include individual light status, controller status, power status, flash operation, communication status, system fault indication and remote alarm output, and it can be integrated with a site SCADA, building-management or airport infrastructure system. Control functions can include automatic day, twilight and night intensity switching by photocell, flash control, synchronization, system enable and disable, fault reporting and remote status indication.
How are the lights mounted and powered?
Typical mounting arrangements are tower platforms, mast brackets, structural steelwork, equipment platforms, rooftop structures and dedicated obstruction-light mounting assemblies. Mounting must provide secure support and keep the required optical orientation under wind and vibration, with suitable access for maintenance. Electrical considerations include supply voltage, AC or DC configuration, circuit, surge and lightning protection, cable routing, earthing, and control and monitoring interfaces, coordinated with the structure's power infrastructure.
What is checked when commissioning obstruction lights?
Commissioning covers mounting and structural fixing, light orientation, electrical connections, supply voltage and protection, light operation, colour and optical output, flash characteristics, synchronization between lights, automatic control functions, monitoring and alarm outputs, and cable routing and weather sealing. Record the results. Where required, photometric verification should be performed using suitable calibrated measurement equipment and the applicable procedure.
How should obstruction lights be maintained safely?
Maintenance may include visual inspection, cleaning optical surfaces, checking mounting hardware, cable entries and electrical connections, testing flash operation and synchronization, verifying monitoring signals, and inspecting surge protection and enclosure integrity. Isolate and lock off the supply before servicing, as some units hold stored energy after switch-off, and work at height only under the site permit-to-work and fall-protection procedures. Set intervals from the installation environment, manufacturer recommendations and site procedures.
What are common faults, and what should be done if a light fails?
Typical conditions are a light not operating (check supply, protection and controller), reduced visibility (inspect and clean the optical window), incorrect flashing (verify flash configuration), lights out of synchronization (check the synchronization system), monitoring alarms, intermittent operation, moisture inside the enclosure and light movement from a loose mounting. A failed obstruction light is an aviation safety matter and should be reported promptly to the aviation authority or NOTAM originator under the airport and authority procedure.
Can high intensity obstruction lights be used to replace or retrofit an existing system?
Yes, where legacy equipment needs replacement, improved reliability or updated control and monitoring. The evaluation should consider the existing classification, light positions, structure geometry, required intensity, flash characteristics, supply voltage, control equipment, synchronization method, monitoring interfaces, cable arrangement and current aviation requirements. A replacement should be selected on the complete optical, electrical and operational requirements rather than physical dimensions alone.
Which standards apply to high intensity obstruction lighting?
References include ICAO Annex 14 Vol. I Chapter 6 with Doc 9157 Part 4, FAA AC 70/7460-1N and AC 150/5345-43J (obstruction lighting equipment, including L-856 high-intensity flashing white), and DGCA India CAR Section 4 with the airport NOC conditions. Near an aerodrome, an aeronautical study should decide whether night intensity needs reducing to avoid dazzling pilots. Verify the current edition of each reference.
What information is needed for an obstruction light assessment?
Provide the structure type, overall height and location, the applicable aviation authority, the Type A or Type B requirement, light colour, intensity and flashing requirements, the number of lighting levels and quantity of lights, available power supply, existing control system, synchronization and monitoring requirements, mounting arrangement, environmental conditions, and whether it is a new installation or a replacement. This lets the configuration be evaluated as part of the complete structure rather than as an individual light.
Procurement Information for Indian Projects
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.
- Manufacturer / OEM authorisation
- Country of origin and local-content declaration (for Make in India purchase preference)
- Type-test and routine-test certificates, and the FAA / ICAO / IEC compliance documents named in the specification
- Datasheets, drawings and installation instructions
- Warranty, delivery period and spares support
- GeM catalogue or tender-portal requirements, where applicable
Request Obstacle-Lighting Assessment
Planning obstruction lighting for a very tall tower, mast, major infrastructure structure or other significant aviation obstacle? Send us the structure height, location, existing or proposed lighting arrangement, applicable aviation authority, required Type A/B classification, power supply and project specification. We can review the application and recommend the appropriate High Intensity Obstruction Light configuration, including optical characteristics, flash operation, mounting, control and monitoring requirements.
Request an obstacle-lighting assessment and technical documentation from Precision AGL Solutions.
- Emailprecisionaglsolutions@gmail.com
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Engineering Note
High-intensity obstruction-light classification, luminous intensity, colour, flash characteristics, lighting levels, synchronization and operating requirements are application- and authority-dependent. Exact product parameters should be confirmed against the approved aviation lighting assessment and current requirements applicable to the project before procurement or installation.
Product Disclaimer
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.