Airfield Signs
Airfield Location Sign for Taxiways & Movement Areas
Clear identification of aircraft position within the movement area
Location signs tell pilots and vehicle operators where they are on taxiways, at intersections, runway exits and apron movement areas, with legend, colour, luminance and mounting selected from the approved signage plan.
Supplied by Precision AGL Solutions
Product Overview
Airfield Location Sign
What It Is
Location signs identify the taxiway, runway or other movement-area location where the sign is installed, giving pilots and vehicle operators positional information about their current location.
Precision AGL Solutions supplies location signs for taxiways, runway exits, intersections, apron movement areas and other locations needing clear positional identification.
Typical Legends
- Taxiway designations
- Runway designations where applicable
- Intersection or location identifiers
- Other approved movement-area location references
Supplied as internally illuminated (LED or other approved source) or retroreflective (non-illuminated, where the standard permits); elevated or ground-mounted; single- or double-face as required.
Applications
Where Location Signs Are Used
Taxiway locationPositional confirmation without directing to a destination.
Taxiway intersectionsPosition within the taxiway network.
Runway exits and entriesCoordinated with runway designation and runway-holding position signs.
Apron movement areasAccount for aircraft paths, vehicle routes and markings.
Complex taxiway networksConsistent system for positional awareness.
UpgradesNew build, rehabilitation, LED modernization.
Location vs Other Signs
Location Sign vs Direction Sign
| Sign Type | Primary Function | Typical Information |
|---|---|---|
| Location Sign | Identifies current position | Taxiway / location designation |
| Direction Sign | Provides route information | Taxiway or destination direction |
| Mandatory Instruction Sign | Communicates a restriction or mandatory instruction | Runway holding position, NO ENTRY, etc. |
A location sign should not be configured as a directional sign merely because both may contain taxiway designations. This distinction matters when preparing the airport signage schedule.
Location Sign Colour
Yellow on Black
ICAO-Based Aerodromes
Location signs have a yellow inscription on a black background, clearly distinct from mandatory instruction signs (white inscription on red). A stand-alone location sign normally carries a yellow border. Sign-face construction, border and optical characteristics follow the applicable standard.
Avoiding Confusion
Position and configure the sign so it does not conflict with:
- Mandatory instruction, direction and information signs
- Runway and taxiway markings
ICAO & FAA Applications
Standard-Specific Approach
ICAO
Location signs identify the taxiway or movement-area location of the aircraft and form part of the aerodrome visual guidance system.
- Legend and sign location
- Dimensions and character size
- Colour, illumination, mounting
Establish all of these from ICAO requirements and the approved aerodrome signage plan.
FAA (L-858)
Location signs are part of the FAA runway and taxiway sign family, distinguished from mandatory instruction, direction and information signs. The current L-858 specification establishes:
- Sign type, size and style
- Legend and character dimensions
- Construction, illumination, electrical configuration
- Mounting and environmental performance
Legend & Character Height
Taken From the Approved Signage Plan
Legend Configuration
- Taxiway letter or combination
- Location identifier
- Runway designation where specifically required
- Other standardized location information
Check designation, character order, spacing, face orientation and viewing direction. Review custom legends before manufacturing: an incorrect face is an operationally misleading visual aid.
Character Height & Dimensions
Character height comes from the applicable standard, not a universal value. Factors:
- Sign location, taxiway geometry
- Cockpit viewing position and distance
- Operating conditions, sign type
Overall dimensions follow character height, character count, legend arrangement, borders, illumination and mounting. FAA L-858 gives standardized configurations; ICAO projects use the approved sign schedule.
Illumination & LED
Visual Performance, Not Just Light Output
Illumination Options
- Internal LED illumination
- Other approved internal light sources
- Retroreflective face (non-illuminated, where permitted)
- Series-circuit powered illumination
- Direct electrical supply
- Project-specific LED driver systems
Under ICAO Annex 14 a sign must be illuminated when used in runway visual range conditions below 800 m, at night with instrument runways, and at night with non-instrument runways of code number 3 or 4. In other cases a retroreflective sign may be acceptable. Confirm the requirement for your aerodrome with the airport authority.
LED Location Sign
Benefits: long service life, less lamp replacement, efficient and stable illumination, reduced maintenance, compatibility with modern airport lighting.
LED signs must still satisfy requirements for colour, luminance, uniformity, electrical compatibility, environmental performance and optical construction.
Electrical Configuration
Series Circuit, Direct Supply or LED Driver
Series Circuit
Integrated into a constant-current airfield lighting circuit via an isolating transformer. Signs can also run from a parallel constant-voltage circuit where the airport design uses one.
Direct Supply
Dedicated electrical source where permitted by the project.
LED Driver
An LED sign may incorporate an appropriate driver or power-conversion system.
CCR Compatibility Considerations
- Circuit current and isolation transformer rating
- Sign load and number of signs
- Circuit configuration
- Brightness control and monitoring (sign output should follow the airfield brightness steps)
Confirm Before Procurement
The sign should match the complete electrical system; confirm the required configuration before ordering.
Mounting & Frangibility
Support Arrangements
Typical Components
- Frangible support posts
- Mounting brackets, base plates, anchor hardware
- Sign mounting channels
- Frangible couplings
- Cable-entry provisions
Signs on the movement area must be frangible and mounted low enough to clear propellers and engine pods. The support must also give structural stability.
Frangibility
Signs sit close to aircraft operating surfaces, so supports must be frangible:
- Frangible posts and breakaway couplings
- Lightweight support assemblies
- Controlled failure interfaces
Evaluate sign and support as a system. Do not substitute a generic breakaway component without confirming compatibility with the approved design.
Environmental Performance
Outdoor Airfield Exposure
- Rain and humidity
- Dust and sand
- UV radiation
- Temperature variation
- Wind
- Cleaning chemicals
- De-icing chemicals where applicable
- Coastal environments
Construction should provide corrosion resistance, weather protection, UV resistance, electrical sealing, drainage, mechanical durability and surface protection.
Technical Data
Typical / Required Information
| Parameter | Typical / Required Information |
|---|---|
| Product type | Airfield location sign |
| Application | Taxiway / movement-area location identification |
| FAA classification | L-858L location sign (size, style and class per AC 150/5345-44L) |
| Sign category | Location (ICAO Annex 14 / FAA) |
| Legend | Project-specific |
| Character height, sign dimensions | Standard / project specific |
| Background and legend colour | Yellow inscription on black background; yellow border for a stand-alone sign |
| Illumination | Internally illuminated, or retroreflective where permitted |
| Light source | LED or approved technology |
| Luminance and uniformity | Per applicable standard |
| Electrical input | Project / equipment specific |
| Series circuit compatibility | Where applicable |
| Housing | Airfield-grade construction |
| Mounting and frangibility | Elevated / ground-mounted; per applicable requirement |
| Environmental protection | Airfield outdoor environment |
| Operating temperature, cable entry, weight | Equipment / manufacturer specific |
| Documentation | Datasheet, drawing, applicable compliance documents |
Confirm exact values against the selected configuration and current manufacturer documentation.
Sign Selection Process
Seven Steps to Specify a Sign
Identify locationTaxiway, intersection, runway exit, apron route
Confirm functionLocation, direction, mandatory or information
Confirm legendApproved signage schedule
Confirm standardICAO, FAA, national authority, airport spec
Confirm illuminationInternal / LED / series / direct
Confirm mountingHeight, orientation, foundation, frangibility, cabling
Confirm environmentLocal and structural requirements
Installation Considerations
Location, Orientation and Viewing
Sign Location
Place at the approved location with adequate visibility, avoiding conflicts with:
- Aircraft and vehicles
- Other signs and lighting
- Pavement markings, navigation aids
Sign Orientation
Face the intended viewing direction. Where aircraft approach from multiple directions, the approved design may need multiple faces or separate assemblies.
Viewing Conditions
- Daylight and night
- Low ambient illumination
- Poor visibility
- Rain or contamination
Minimize unnecessary visual obstruction.
Coordination With Taxiway Markings
Reinforce, Don't Conflict
Coordinate With
- Taxiway centreline and edge markings
- Runway-holding and intermediate holding positions
- Direction and mandatory instruction signs
- Taxiway lighting
Principle
The sign should reinforce the approved movement-area layout rather than introduce a conflicting designation.
Commissioning
Typical Procedure
- Verify sign type
- Verify legend
- Confirm sign location
- Check orientation
- Verify support and foundation
- Check frangible arrangement where applicable
- Inspect sign housing
- Energize the sign
- Verify illumination
- Check colour
- Check uniformity
- Verify electrical operation
- Confirm visibility from the intended taxi route
- Record the installed configuration
Final acceptance follows applicable airport and manufacturer procedures.
Maintenance
Routine Inspection
Sign Face
- Scratches, cracks
- Fading, discolouration
- Contamination, damage
Illumination
- Failed LED modules, dark areas
- Uneven illumination, reduced output
- Driver faults
Housing
- Corrosion, water ingress
- Damaged seals, loose panels
- Structural deterioration
Mounting
- Posts, fasteners, base plates
- Frangible components
- Foundation, sign alignment
Common Problems
Causes and Recommended Actions
| Problem | Possible Causes | Recommended Action |
|---|---|---|
| Taxiway designation incorrect | Wrong legend, outdated signage plan, manufacturing error, taxiway renaming | Verify against the latest approved signage schedule before installation |
| Difficult to read at night | Failed LED modules, reduced illumination, dirty face, optical degradation, supply problem | Inspect complete sign and electrical interface |
| Not visible from intended taxiway | Incorrect orientation, obstruction, wrong position or face, layout changes | Verify approved location and viewing direction |
| Physical damage | Vehicle impact, aircraft contact, weather, corrosion, foundation movement | Inspect complete sign and support before returning to service |
Procurement Checklist
For a Quotation, Provide
- Airport / project
- Governing standard
- Sign type
- Exact legend
- Character height
- Quantity
- Sign dimensions if specified
- Illuminated or retroreflective
- LED requirement
- Electrical supply
- Series-circuit requirements
- Mounting arrangement
- Frangible requirements
- Installation location
- Environmental requirements
- Required documentation
An approved airport signage schedule or sign-face drawing is particularly useful for custom configurations.
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 & References
Verify the Applicable Edition
Relevant References
- ICAO Annex 14 Vol. I, Chapter 5 and Appendices 1 and 4, and Doc 9157 Part 4
- FAA AC 150/5345-44L — Specification for Runway and Taxiway Signs
- FAA AC 150/5340-18H — Standards for Airport Sign Systems
- DGCA India CAR Section 4 and other national requirements
- Airport-specific signage specifications and approved plans
- Manufacturer installation and maintenance documents
Note
Verify the current edition before procurement. For FAA projects, establish the L-858 sign type (L-858L for location signs), size, style and class from the current FAA specification.
Documentation & Support
What Precision AGL Solutions Provides
Documentation
- Product datasheet, sign-face and GA drawings
- Legend layout, electrical schematic
- Mounting drawing, foundation and frangibility information
- Photometric information, material specification
- Installation and maintenance instructions
- Compliance documentation where applicable
Support For
- New construction, taxiway development
- Runway rehabilitation, apron expansion
- Movement-area upgrades, sign replacement
- LED modernization, refurbishment
- ICAO-based installations and FAA L-858 applications
Includes selection, legend review, dimensional configuration, electrical-interface coordination and documentation.
FAQ
Airfield Location Sign — Frequently Asked Questions
What is an airfield location sign?
A location sign identifies the taxiway, runway or other movement-area location where the sign is installed, giving pilots and vehicle operators positional information about their current location. Typical legends are taxiway designations, runway designations where applicable, and intersection or location identifiers.
What colour is a location sign?
Location signs have a yellow inscription on a black background, clearly distinct from mandatory instruction signs, which use a white inscription on red. A stand-alone location sign normally carries a yellow border, and sign-face construction, border and optical characteristics follow the applicable standard.
How does a location sign differ from a direction sign or a mandatory instruction sign?
A location sign identifies the current position, a direction sign provides route information, and a mandatory instruction sign communicates a restriction such as a runway holding position or NO ENTRY. A location sign should not be configured as a directional sign merely because both may contain taxiway designations, and this distinction matters when preparing the airport signage schedule.
What is an FAA L-858L sign?
Location signs are part of the FAA runway and taxiway sign family, and the type for location signs is L-858L, with size, style and class set under AC 150/5345-44L. Sign layout and system standards are in AC 150/5340-18H. For ICAO projects, legend, dimensions, colour, illumination and mounting come from Annex 14 and the approved aerodrome signage plan.
Must a location sign be illuminated?
Under ICAO Annex 14 a sign must be illuminated when used in runway visual range conditions below 800 m, at night with instrument runways, and at night with non-instrument runways of code number 3 or 4. In other cases a retroreflective sign may be acceptable, so confirm the requirement for your aerodrome with the airport authority.
How are the legend and character height decided?
The legend comes from the approved airport signage plan, and character height comes from the applicable standard rather than a universal value. Check designation, character order, spacing, face orientation and viewing direction, and review custom legends before manufacturing, because an incorrect face is an operationally misleading visual aid.
How is a location sign powered?
It can be integrated into a constant-current airfield lighting circuit through an isolating transformer, run from a parallel constant-voltage circuit where the airport design uses one, supplied directly from a dedicated source where permitted, or fitted with an LED driver. Check the circuit current, isolation transformer rating, sign load and number of signs, and note that sign output should follow the airfield brightness steps.
How is a location sign mounted and installed?
Signs on the movement area must be frangible and mounted low enough to clear propellers and engine pods, using frangible posts, breakaway couplings and controlled failure interfaces. Do not substitute a generic breakaway component without confirming compatibility with the approved design. Install at the approved location, facing the intended viewing direction, and where aircraft approach from several directions the design may need multiple faces or separate assemblies.
What are the common problems with location signs?
An incorrect taxiway designation can come from a wrong legend, an outdated signage plan, a manufacturing error or taxiway renaming, so verify against the latest approved signage schedule before installation. A sign that is difficult to read at night may have failed LED modules, a dirty face or a supply problem, and one that is not visible from the intended taxiway may have incorrect orientation, an obstruction or the wrong position. Physical damage from vehicle impact, aircraft contact or corrosion needs inspection of the complete sign and support.
What should be provided for a location sign quotation?
Provide the airport and project, the governing standard, the sign type, the exact legend, the character height, the quantity, whether it is illuminated or retroreflective, the LED requirement, the electrical supply and series-circuit requirements, the mounting and frangible requirements, the installation location, environmental requirements and the documentation needed. An approved airport signage schedule or sign-face drawing is particularly useful for custom configurations.
Is it safe to work on an illuminated sign on a live series circuit?
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 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 Airfield Sign Selection
For an airfield location sign quotation or technical review, provide the airport/project standard, sign legend, intended installation location, character height, illumination requirement and quantity where available. We can support selection of suitable location signage for taxiways, intersections, runway exits and apron movement areas.
- Emailprecisionaglsolutions@gmail.com
- Websiterahulsharmaagl.in
- LinkedInPrecision AGL Solutions
- Phone+91 98214 96412
Engineering Note
Airfield location signs form part of the airport's integrated visual guidance system. Sign function, legend, colour, character dimensions, illumination, mounting position and support arrangement should be established from the applicable aviation standard and approved airport signage plan.
Location signs should not be substituted for mandatory instruction or direction signs where those functions are required. Exact dimensions, luminance, electrical characteristics and mounting details are standard- and project-specific: confirm the current standard, approved sign schedule and manufacturer datasheet 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.