Airfield Signs
Edge Lit Airfield Sign Boards for Movement Areas
Clear night-time visual information across changing ambient-light conditions
Edge-lit sign boards distribute light through the sign face to give clear, consistent legend visibility during night operations, configured for dimensions, legend, illumination performance and mounting to suit your airport layout and project requirements.
Supplied by Precision AGL Solutions
Product Overview
Edge Lit Airfield Sign Boards
What It Is
Edge-lit sign boards use an illumination arrangement designed to distribute light through the sign face, giving clear night-time visual information where signs must stay visible during night operations and changing ambient-light conditions.
Precision AGL Solutions supplies them for taxiway identification, location information, directional guidance and apron applications. Dimensions, legend, illumination performance and mounting are selected from the airport layout and project requirements.
Typical System
- Sign face and legend
- Edge-lighting or internal optical assembly
- LED illumination system
- Sign enclosure and electrical connection arrangement
- Mounting supports with frangible or breakaway components
- Sealing and environmental protection features
Applications
Configured for Each Airfield Function
Taxiway identificationTaxiway identification signs and intersection identification.
Location signsCurrent taxiway or movement-area location.
Direction signsDirectional guidance across movement areas.
Apron & standApron and aircraft stand signage.
Upgrades & replacementInfrastructure upgrades and replacement of existing illuminated signs.
New constructionNew airfield construction and expansion projects.
Coordinate sign configuration with pavement markings, taxiway geometry, aircraft operating areas and the overall airfield lighting system.
Sign Categories & Colours
Colour Follows the Sign Category
| Sign category | Legend / background (ICAO Annex 14, FAA) | Typical use |
|---|---|---|
| Mandatory instruction | White legend on red background | Runway designation, CAT I/II/III holding positions, runway-holding position, no-entry |
| Location | Yellow legend on black background (yellow border where required) | Identifies the taxiway or runway the aircraft is on |
| Direction | Black legend on yellow background | Identifies the taxiway to turn onto and its direction |
| Information | Black legend on yellow background | Operational information such as stand or apron routing, as set by the authority |
Why It Matters
- Colours are fixed by sign category, not chosen per project
- Red is reserved for mandatory instruction signs
- Each sign face must meet the chromaticity and luminance limits for its colour
- A location sign is normally provided together with direction signs, and with runway designation signs except at runway/runway intersections; confirm the pairing in Annex 14 Chapter 5
Engineering Note
Colour, legend style and character form are set by the applicable standard and the airport signage plan. Confirm them in the approved sign schedule before fabrication.
Edge-Lit Illumination System
A Complete-Sign Design Approach
System Aims
- Consistent legend illumination
- Good visibility at the required viewing distance
- Controlled brightness, reduced localized hot spots
- Suitable contrast between legend and background
- Reliable night-time operation, long service life with maintenance
Design Principle
Under ICAO Annex 14, signs are to be illuminated for night use on instrument runways and on non-instrument runways of code number 3 or 4, and when used in runway visual range below 800 m; otherwise a retroreflective sign may be acceptable where the authority permits. Sign luminance should follow the airfield brightness steps so that signs match the surrounding lighting. LEDs are positioned and coupled with suitable optics to distribute light across the face. Evaluate the optical design as a complete sign assembly, not the LED source independently of the sign face and legend.
LED Technology
Efficient Illumination for Modern Signage
Potential Advantages
- Low electrical consumption, long operating life
- Reduced lamp replacement and maintenance
- Stable illumination, rapid switching
- Compatibility with modern control systems
Electrical Interface
Select LED configuration, driver arrangement, operating voltage and control interface to suit the project electrical architecture. Where signs integrate with an airfield lighting system, confirm the interface during project design.
Legend & Characters
Determined by the Airport Signage Plan
Legend May Include
- Taxiway identifiers, runway-related information
- Directional arrows, location identifiers
- Stand or apron references, operational information
- Combined characters and symbols
Character Height & Contrast
Select character height and legend size from the required viewing distance and applicable airfield signage criteria. The face should give sufficient legend/background contrast so information stays distinguishable under expected conditions.
Luminance & Uniformity
Readable Without Glare
Luminance
Adequate for the intended operating environment without unnecessary glare or excessive brightness.
Optical Uniformity
- Prevents bright spots and dark corners
- Avoids uneven character illumination
- Keeps the legend well defined and readable at distance
- Verify against the project specification and current signage requirements
Sign Dimensions
Engineered From Legend and Viewing Distance
Design Considerations
- Overall length and height, face thickness
- Character height, legend spacing, arrow dimensions
- Internal optical clearance, mounting clearance
- Cable entry position
Principle
Large signs may need additional structural support or multiple mounting points. Establish final dimensions from the approved sign schedule, not independently of the sign location.
Construction & Materials
Built for Continuous Outdoor Exposure
Construction May Include
- Corrosion-resistant materials, protective finishes
- Sealed electrical compartments
- Weather-resistant sign faces, durable optics
- Protected cable entries, robust mounting hardware
Material Selection
Consider airport environmental conditions and the required installation service life: moisture, dust, UV, temperature variation and cleaning or maintenance activity.
Mounting & Frangibility
Support and Clearance
Mounting Options
- Ground-mounted supports, dedicated sign posts
- Breakaway/frangible supports, base plates
- Adjustable or project-specific support structures
Safety
Mounting must be stable while keeping the required clearance from aircraft and operating areas. Signs on the movement area must be frangible and low enough to clear aircraft propellers and engine pods. Confirm sign height, distance from the pavement edge and the frangible point in the airfield safety and clearance assessment, against the sign location plan.
Electrical Configuration
Engineered for the Project Power Architecture
Relevant Parameters
- Series or parallel circuit, transformer rating, LED driver configuration
- Rated power, current requirements
- Cable connection, switching, dimming
- Control interface, surge protection
- Earthing/grounding arrangement
Control Integration
Airfield signs normally run on a series circuit (constant current, through an isolating transformer) or a parallel circuit (constant voltage). The LED driver must suit the transformer secondary or supply voltage and respond correctly to the regulator brightness steps. Confirm the electrical interface before procurement.
Environmental Protection
Designed for Continuous Outdoor Operation
Considerations
- Rain and moisture, dust, UV exposure
- Temperature cycling, wind loading
- Corrosion, condensation
- Cleaning and maintenance conditions
Verification
Confirm the required ingress protection and environmental classification against the actual installation environment and project specification.
Technical Data
Typical Project Considerations
| Parameter | Typical Project Consideration |
|---|---|
| Product type | Edge-lit airfield sign board |
| FAA sign types (L-858) | L-858R mandatory instruction; L-858Y direction, destination and information; L-858L location (confirm size, style and class per AC 150/5345-44L) |
| Sign dimensions | Project-specific |
| Legend | Taxiway, location, direction, apron or other approved information |
| Character configuration | Project-specific |
| Character height | According to viewing distance and signage requirements |
| Illumination | LED edge-lit/internal optical arrangement |
| Luminance | Project-specific |
| Optical uniformity | Controlled across sign face |
| Input power | Project-specific |
| Electrical interface | According to airfield lighting/signage system |
| Mounting | Ground-mounted, supported or project-specific |
| Frangibility | Where required by installation |
| Construction | Outdoor airfield-rated materials |
| Environmental protection | Project-specific |
| Cable entry | Project-specific |
| Control | Local or integrated airfield lighting control, where applicable |
Final technical values should be confirmed against the selected sign configuration and project specification.
Edge-Lit Sign Selection
Begin With the Sign Function
FunctionLocation, direction, taxiway, apron, stand
LegendExact approved characters, numbers, arrows, symbols
Character heightPer viewing distance and criteria
DimensionsLegend, spacing, optical performance
IlluminationLED arrangement, luminance, uniformity
MountingArea, pavement, clearance, frangibility
ElectricalVoltage, power, control, cable, connection
Installation
Verify Before Installation
Coordinate With
- Approved sign location, aircraft clearance
- Taxiway and apron geometry, pavement markings
- Driver and cable access, cable routing, drainage
- Foundation or support and frangible support requirements
- Visibility from the intended approach direction
Principle
Install so the legend stays clearly visible without obstruction by aircraft, vehicles, structures or other equipment.
Coordination With Airfield Markings
A Consistent Sequence of Visual Information
Review Alongside
- Taxiway centreline and edge markings
- Holding-position, stand and apron markings
- Taxiway centreline lights, stop bars
- Runway guard lights, other illuminated signs
Purpose
Edge-lit signs work with markings and lighting to provide complete visual guidance. Correct coordination reduces conflicting or ambiguous information.
Commissioning
Inspect Against Project Documentation
InspectPhysical inspection of sign assembly
MountingSupport condition
ElectricalConnection checks
IlluminationLED testing, legend visibility, uniformity
ControlSwitching checks
Night checkNight-time visual inspection, orientation
DocumentRecord installed configuration
Where required, complete commissioning within the wider airfield lighting and signage acceptance process.
Maintenance
Periodic Inspection Remains Necessary
Activities
- Cleaning the sign face, checking for physical damage
- Inspecting mounting hardware, cable entries, electrical connections
- Checking LED performance, uneven illumination, moisture ingress
- Verifying legend condition, sign colour and luminance, coatings and structural components
Principle
LED systems generally reduce routine light-source replacement compared with lamp-based systems, but the complete sign assembly still requires periodic inspection.
Common Problems
Typical Problems and Causes
| Problem | Possible Causes / Notes |
|---|---|
| Uneven illumination | Optical component issue, LED failure, contamination, internal deterioration |
| Reduced brightness | LED or driver problems, electrical supply issues, contamination, component ageing |
| Moisture inside the sign | Compromised sealing, cable-entry problems, enclosure damage |
| Damaged legend or sign face | Physical damage reduces readability; assess promptly |
| Mounting damage | Loose, damaged or corroded supports; inspect before continued operation |
Replacement & Upgrade
Modernizing Ageing Illuminated Signs
Applications
- Replacement of damaged signs, LED conversion
- Airport modernization, taxiway redevelopment
- Apron expansion, signage standardization
- Replacement of ageing illuminated systems
Before Procurement
When replacing an existing sign, check the new unit against the existing foundation, cable routing, electrical interface and sign schedule.
Procurement Checklist
When Requesting an Edge-Lit Sign Board, Provide
Sign Details
- Airport/project name, sign type
- Approved legend, character height, number of characters
- Arrow or symbol requirements
- Required dimensions, installation location
- Mounting arrangement, frangibility requirements
System & Documentation
- Illumination requirements
- Electrical supply, control requirements
- Environmental conditions
- Applicable project standards
- Required documentation
Safety
Electrical Safety — Isolation and Lock-Out
WARNING — never open a live series circuit. An open series circuit driven by a constant-current regulator can produce dangerously high voltage. Opening, cutting or disconnecting any part of an energised circuit can cause serious injury or death and damage equipment.
- De-energise the circuit at the regulator and apply the site lock-out / tag-out (LOTO) procedure before any work
- Where the circuit must be isolated or shorted, use the series circuit cut-out switch or approved isolation device — not an improvised bypass
- Verify the circuit is de-energised and the output is isolated before touching conductors, connectors, splices or transformers
- Work only under the airport's permit-to-work system, using qualified personnel and the manufacturer's instructions
- Follow the applicable national electrical safety regulations and site procedures
Standards & Project Compliance
Verify the Applicable Edition
Relevant References
- ICAO Annex 14 Vol. I (Chapter 5, signs; Appendix 1, colours; Appendix 4, taxiing guidance sign design)
- ICAO Doc 9157 Aerodrome Design Manual, Part 4
- FAA AC 150/5345-44L (runway and taxiway signs) and AC 150/5340-18H (sign standards)
- DGCA India CAR Section 4 and applicable national requirements
- Project-specific airfield lighting specifications
- Airport signage schedules and layout drawings
Principle
Select and manufacture signage to the applicable airport requirements. Confirm the applicable standard and edition for each project before final technical approval.
Documentation & Support
Practical Support Based on the Actual Installation
Documentation
- Datasheets, technical specifications, sign schedules
- General arrangement drawings, mounting details
- Electrical information, installation guidance
- Maintenance, inspection and commissioning documentation
Why Precision AGL Solutions
We select equipment from the actual installation, not a generic product description: sign configuration, legend and character selection, illumination, mounting, electrical interface review, retrofit assessment and technical procurement support.
FAQ
Edge-Lit Airfield Sign Boards — Frequently Asked Questions
What are edge-lit airfield sign boards?
Edge-lit sign boards use an illumination arrangement designed to distribute light through the sign face, giving clear night-time visual information where signs must stay visible during night operations and changing ambient-light conditions. They are used for taxiway identification, location information, directional guidance and apron applications. A typical system has the sign face and legend, an edge-lighting or internal optical assembly, an LED illumination system, an enclosure and electrical connection arrangement, frangible or breakaway mounting supports, and sealing and environmental protection.
What colours and FAA types apply to the different sign categories?
Colour follows the sign category and is not chosen per project. Mandatory instruction signs are white on red, location signs are yellow on black, and direction and information signs are black on yellow. Red is reserved for mandatory instruction signs. FAA types are L-858R for mandatory instruction, L-858Y for direction, destination and information, and L-858L for location, with size, style and class confirmed per AC 150/5345-44L. Each sign face must meet the chromaticity and luminance limits for its colour.
Does an airfield sign have to be illuminated, and what are the benefits of LED edge-lighting?
Under ICAO Annex 14, signs are to be illuminated for night use on instrument runways and on non-instrument runways of code number 3 or 4, and when used where runway visual range is below 800 m. Otherwise a retroreflective sign may be acceptable where the authority permits. LED illumination offers low consumption, long life, reduced lamp replacement, stable output and compatibility with modern control systems. Light is positioned and coupled with optics to spread it across the face, and the optical design should be evaluated as a complete sign assembly.
How are legend, character height and sign size decided?
The legend comes from the airport signage plan and may include taxiway identifiers, runway-related information, arrows, location identifiers and stand or apron references. Character height and legend size are selected from the required viewing distance and the applicable signage criteria, with enough legend and background contrast. Overall dimensions depend on character height, legend spacing, arrow size, internal optical clearance, mounting clearance and cable entry position, and should be taken from the approved sign schedule. Large signs may need additional structural support or multiple mounting points.
How is an edge-lit sign mounted, and why must it be frangible?
Mounting options include ground-mounted supports, dedicated sign posts, breakaway or frangible supports, base plates and project-specific structures. Signs on the movement area must be frangible and low enough to clear aircraft propellers and engine pods. Confirm the sign height, distance from the pavement edge and the frangible point in the airfield safety and clearance assessment, against the sign location plan.
How is an edge-lit sign powered?
Airfield signs normally run on a series circuit (constant current, through an isolating transformer) or a parallel circuit (constant voltage). The LED driver must suit the transformer secondary or supply voltage and respond correctly to the regulator brightness steps. Confirm the electrical interface before procurement, including transformer rating, rated power and current, switching and dimming, control interface, surge protection and earthing.
How are edge-lit signs protected against the environment?
Construction may include corrosion-resistant materials and protective finishes, sealed electrical compartments, weather-resistant sign faces, durable optics, protected cable entries and robust mounting hardware. Consider rain and moisture, dust, UV exposure, temperature cycling, wind loading, corrosion, condensation and cleaning activity. Confirm the required ingress protection and environmental classification against the actual installation environment and project specification.
What are the common problems with edge-lit signs?
Typical problems are uneven illumination (an optical component issue, LED failure, contamination or internal deterioration), reduced brightness (LED or driver problems, supply issues, contamination or ageing), moisture inside the sign (compromised sealing, cable-entry problems or enclosure damage), a damaged legend or sign face, which reduces readability and should be assessed promptly, and damaged, loose or corroded mounting supports, which should be inspected before continued operation.
What should be provided when requesting or replacing an edge-lit sign?
Provide the airport or project name, sign type, approved legend, character height, number of characters, arrow or symbol requirements, required dimensions, installation location, mounting arrangement, frangibility requirements, illumination requirements, electrical supply, control requirements, environmental conditions, applicable project standards and required documentation. When replacing an existing sign, check the new unit against the existing foundation, cable routing, electrical interface and sign schedule.
Which standards apply to edge-lit airfield signs?
References include ICAO Annex 14 Vol. I (Chapter 5 on signs, Appendix 1 on colours and Appendix 4 on taxiing guidance sign design), ICAO Doc 9157 Part 4, FAA AC 150/5345-44L for runway and taxiway signs, FAA AC 150/5340-18H for sign standards, DGCA India CAR Section 4 and project-specific airfield lighting specifications, signage schedules and layout drawings. Confirm the applicable standard and edition for each project before final technical approval.
Is it safe to work on an edge-lit sign while the circuit is energised?
No. An open series circuit driven by a constant-current regulator can produce dangerously high voltage, and opening, cutting or disconnecting any part of an energised circuit can cause serious injury or death. De-energise the circuit at the regulator, apply the site lock-out / tag-out procedure, use the series circuit cut-out switch or an approved isolation device and work under the airport’s permit-to-work system. See the electrical safety warning on this page.
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 Edge-Lit Sign Details
Need an edge-lit sign board for a new airport project, taxiway upgrade, apron development or replacement application? Send the sign type, approved legend, character height, required dimensions, installation location and electrical requirements. We can help determine the edge-lit configuration, illumination arrangement, mounting solution and project documentation.
- Emailprecisionaglsolutions@gmail.com
- Websiterahulsharmaagl.in
- LinkedInPrecision AGL Solutions
- Phone+91 98214 96412
Engineering Note
Sign dimensions, luminance, optical uniformity, character configuration, mounting, frangibility, electrical interface and environmental protection are project-dependent.
Final equipment selection should be based on the approved airport signage layout, applicable aviation standards and the current project specification.
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.