L-852 – FAA Specification for PAPI Systems – Standards

1. Definition and Overview

L-852 defines a standardized series of in-pavement, aircraft-rated light fixtures serving as critical components of airport taxiway and runway lighting systems. Originating from the Federal Aviation Administration (FAA) and harmonized with ICAO standards, L-852 fixtures are engineered to withstand the intense physical and operational stresses of an airport environment. These robust lights are embedded directly into paved surfaces with minimal protrusion (not exceeding 6.3 mm), preventing hazards to aircraft and ensuring smooth ground operations. Their design endures aircraft wheel loads, de-icing chemicals, jet blast, and extreme weather, making them suitable for all airport categories, including those serving heavy commercial aviation.

L-852 lights serve multiple visual guidance purposes: taxiway centerline delineation, clearance bar marking, runway guard warning, stop bar indication, and other specialized visual aids. While not classified as PAPI lights themselves (which are surface-mounted for approach slope guidance), L-852 specification and compliance protocols establish the operational and safety framework vital for integrating PAPI systems—especially where visual aids converge at runway thresholds or taxiway intersections.

The integration of L-852 lights with PAPI and other visual systems enhances the overall safety and efficiency of airport ground movement. These fixtures must meet stringent photometric requirements (color, intensity, uniformity) per FAA AC 150/5345-46 and ICAO Annex 14. Both incandescent and advanced LED light sources are supported, with LEDs providing significant gains in efficiency, longevity, and reliability. Monitoring and fail-safe features (such as remote status indication and automatic shutdown on failure) further reinforce airfield safety. Global adoption of L-852 fixtures attests to their fundamental role in airfield infrastructure, directly impacting approach, landing, taxi, and takeoff operations.

2. Regulatory Framework and Standards

The L-852 series is governed by a comprehensive set of regulatory standards and guidance documents:

• FAA AC 150/5345-46: Specifies design, construction, testing, and performance for runway and taxiway light fixtures, detailing requirements for photometric intensity, color, beam spread, environmental sealing, and durability.
• FAA AC 150/5340-30: Outlines design and installation details for all airport visual aids, including correct placement and orientation of L-852 lights.
• ICAO Annex 14, Volume I: Harmonizes color, intensity, and placement requirements for airfield lighting across international airports.
• IEC 61827: Covers technical and safety requirements for airfield lighting, including electrical characteristics, environmental testing, and compatibility with modern constant current regulators (CCR).
• FAA Engineering Brief 67 (EB 67): Governs LED-based light sources, specifying dimming performance, color rendering, and CCR compatibility as the industry transitions from halogen to LED.

Certification is mandatory: all L-852 fixtures must be independently tested and certified (commonly by ETL or equivalent) to FAA and, where applicable, ICAO and IEC standards. Only certified products are allowed on federally funded airport projects. Failure to comply can lead to disqualification and increased liability.

The regulatory landscape also evolves with technology, addressing issues such as LED integration, remote monitoring, and compatibility with new airport lighting control systems.

3. L-852 System Classification

L-852 lights are classified by application, color output, operational environment, and runway visual range (RVR) requirements. Each category is optimized for its specific operational role, ensuring maximum visibility and pilot guidance in all conditions.

3.1. L-852A/B/C/D – Taxiway Centerline Lights

• L-852A/B: Used for taxiway centerlines in straight (A) and curved (B) sections for CAT I/II airports (RVR ≥1200 ft). Colors: green/green, yellow/yellow, or green/yellow.
• L-852C/D: For CAT III operations (RVR <1200 ft), straight (C) and curved (D) sections, with higher intensity and redundancy.

3.2. L-852E/F/G/J/K/S/T – Specialized Configurations

• L-852E/F: Yellow taxiway intersection lights for CAT I/II (E) and CAT III (F).
• L-852G: Flashing yellow runway guard lights for incursion prevention.
• L-852J/K: Curved centerline lights for CAT I (J) and CAT III (K).
• L-852S: Red stop bar lights, remotely controlled for runway entry prevention.
• L-852T: Blue taxiway edge lights for edge delineation.

This classification system allows precise matching of fixture type to operational need, supporting safe and efficient airport ground movement.

4. Physical and Electrical Specifications

4.1. Fixture Design and Construction

L-852 fixtures feature flush-mounted, in-pavement construction for high durability and minimal FOD risk. Housings are typically made from aircraft-grade aluminum or stainless steel, with impact-resistant glass or polycarbonate lenses and robust chemical-resistant gaskets and O-rings. Fixtures fit into FAA L-868A/B base cans, ensuring secure mounting and electrical isolation, and meet IP67 ingress protection for water and dust resistance.

Low-profile designs (≤6.3 mm above grade) prevent damage from aircraft and snow removal. Color-coded and clearly marked, all components are modular and field-replaceable—including LED modules, optics, and drivers. Optional deicing kits (arctic kits) provide thermostatically controlled heating for reliable cold-weather operation.

4.2. Electrical Characteristics

L-852 fixtures operate in a series circuit, powered by a constant current regulator (CCR) at 2.8–6.6 amps. Input voltage is set by the airfield isolation transformer; LED fixtures are fully dimmable and compatible with legacy tungsten halogen systems, per FAA EB 67. Electrical connections use FAA L-823 watertight connectors.

Advanced features include fail-open monitoring for rapid detection and reporting of fixture failures via Airfield Lighting Control and Monitoring Systems (ALCMS).

Actual load varies by source (LED/halogen), color, and arctic kit usage.

4.3. Optical Performance

L-852 fixtures deliver precise photometric performance, exceeding FAA and ICAO requirements for intensity, uniformity, and color. High-powered LEDs maintain chromaticity within tight tolerances, with modular engines rated for 50,000+ hours. Color output is strictly regulated: green (centerline), yellow (hold/intersection), blue (edge), red (stop bar). Beam spread is tailored for straight or curved applications.

All fixtures are tested for photometric compliance at multiple settings, ensuring visibility in all conditions and after exposure to vibration, thermal cycling, and chemical exposure.

4.4. Environmental Performance

L-852 fixtures operate in harsh climates (–55°C to +55°C) and resist UV, ozone, hydraulic fluids, jet fuel, and de-icers. Arctic kits prevent ice/snow buildup. IP67 (or better) sealing prevents water/dust ingress. Chemical resistance testing simulates years of exposure to runway de-icers and fuels. Enhanced sealing options are available for sandy, dusty, or volcanic regions.

5. Compliance and Certification

All L-852 fixtures on federally funded U.S. airport projects must be certified per FAA AC 150/5345-46. Certification is performed by independent labs (ETL, UL), covering photometric, electrical, and environmental standards. Only FAA-CEML-listed products are approved.

LED fixtures must comply with FAA EB 67 for color, intensity, dimming, and reliability. International projects may require concurrent compliance with ICAO Annex 14 and IEC 61827. Additional certifications (EMC, lightning, RoHS) may also apply.

Fixtures must be permanently marked with manufacturer, model, certification, and date. Complete traceability and documentation are required for regulatory inspection and incident investigation. Non-compliance can result in funding loss, disqualification, and liability.

6. Installation and Maintenance

6.1. Installation Practices

Only qualified, certified personnel may install L-852 fixtures. Installation requires FAA L-868A/B base cans, flush mounting, and precise orientation per FAA and manufacturer guidelines. Electrical connections use watertight L-823 connectors. All wiring must conform to FAA and local codes for series circuits. Each fixture is pressure-tested for sealing and visually inspected for color, labeling, and orientation. In-situ photometric testing and ALCMS integration are standard at major airports.

6.2. Maintenance Requirements

Routine maintenance ensures performance and safety:

• Regular inspection and cleaning of optical surfaces (non-abrasive methods)
• Removal of silt, debris, and rubber deposits
• Periodic seal integrity checks and pressure testing
• Electrical testing at all brilliancy settings
• Use of manufacturer-approved replacement parts (LED modules, driver boards, prisms, heaters)
• Remote diagnostics and proactive scheduling (where supported)

Well-maintained L-852 fixtures can provide decades of reliable service, minimizing ground lighting downtime and supporting safe airport operations.

7. Impact and Future Trends

L-852 fixtures represent a backbone of modern airfield lighting. Their adoption has dramatically improved safety, visibility, and operational efficiency for airports worldwide. The ongoing shift to LED technology is reducing power consumption, maintenance costs, and environmental impact, while new smart monitoring and control features promise even greater reliability and integration with airport management systems.

As aviation continues to evolve, L-852 standards are regularly reviewed and updated to incorporate new materials, lighting technologies, and operational best practices, ensuring that airport lighting infrastructure keeps pace with the needs of the global air transport industry.

References:

• FAA AC 150/5345-46: Specification for Runway and Taxiway Light Fixtures
• FAA AC 150/5340-30: Design and Installation Details for Airport Visual Aids
• FAA Engineering Brief 67: Light Emitting Diode (LED) Light Sources for Airfield Lighting
• ICAO Annex 14, Volume I: Aerodromes – Aerodrome Design and Operations
• IEC 61827: Electrical installations for lighting and beaconing of aerodromes

For more information or to discuss your airport’s unique lighting needs, contact our experts or schedule a demo .