THE AGL ENGINEERING CENTRE by Precision AGL Academy · Maintenance

Airport Lighting Maintenance Schedule & AGL Maintenance Checklist

A typical AGL maintenance framework from daily checks to annual inspection, with runway, taxiway, approach, PAPI, CCR, transformer and cable maintenance, photometry, defect classification and records.

Overview

Why Airport Lighting Needs a Planned Maintenance Schedule

Airport lighting is safety-critical infrastructure. A runway, taxiway, approach system or PAPI can keep operating while it quietly degrades, so maintenance has to be a planned preventive programme, not a response to failures. ICAO Annex 14 requires aerodromes to establish maintenance programmes, including preventive maintenance where appropriate, so facilities stay in a condition that does not impair the safety, regularity or efficiency of air navigation.

The goal is the whole system

Preserve the correct pattern, intensity, colour, orientation, electrical performance, availability and reliability of the complete lighting system, not just keep lamps lit.

A practical schedule combines

Routine operational inspection, preventive maintenance, electrical testing, component inspection, photometric verification, corrective maintenance, post-maintenance testing, serviceability monitoring and documented trend analysis.

This is a typical framework for planning and contracts. It does not replace the airport's approved maintenance programme, applicable DGCA, AAI or other State requirements, manufacturer instructions, runway operating category or project specifications. FAA AC 150/5340-26C, which FAA lists as Active (issued 20 June 2014), describes a scheduled preventive-maintenance inspection programme for visual aids and their cable systems. For ICAO Annex 14 Volume I, Amendment 18 is applicable from 27 November 2025 unless otherwise indicated.

From requirement list to plan, safe work, verification and records.

HOW REQUIREMENTS TRAVEL INTO MAINTENANCE 1 REQUIREMENT LIST Standards, manufacturer data, regulator rules and contract terms OUTPUT: MAINTENANCE ITEMS 2 MAINTENANCE PLAN Tasks, intervals, spares, tools and acceptable condition OUTPUT: WORK INSTRUCTIONS 3 PREPARE SAFELY Permit, isolation, earthing, tower coordination and spares OUTPUT: SAFE TO WORK 4 CARRY OUT WORK Preventive tasks and corrective repairs OUTPUT: WORK DONE 5 VERIFY Post-work tests and checks against the acceptable condition OUTPUT: FIT FOR SERVICE 6 RECORD & REVIEW Records signed, circuit restored, findings reviewed against intervals OUTPUT: MAINTENANCE RECORDS FEEDBACK LOOP Findings, failures and repeat faults go back to the plan, so tasks, intervals and spares are reviewed against real results. PLAN FIRST · THEN ISOLATE, WORK, VERIFY, RESTORE AND RECORD SIMPLIFIED SEQUENCE · FOLLOW YOUR SITE PERMIT AND ISOLATION PROCEDURE
Figure 1. A planned schedule turns the maintenance requirement into a plan, safe work, verification and records.
AGL Visual Encyclopedia: Maintenance Requirement Flow Preventive Maintenance Sequence Serviceability of Critical Lights
Interactive

Maintenance Schedule by Frequency

Pick a frequency to see typical activities. Adjust to the aerodrome: a CAT II/III runway, a busy taxiway system or an LED installation with condition monitoring may need more frequent or more specialized checks.

Typical activities

    Worth knowing

      Overview Table

      Maintenance Frequency at a Glance

      FrequencyTypical maintenance activities
      Daily / operationalVisual condition, lighting status, reported faults, obvious damage, serviceability, lens condition, signs and PAPI status
      WeeklyFittings, signs, visible damage, cleanliness, PAPI condition and alignment where specified, connectors and exposed equipment
      MonthlyElectrical and physical inspection, internal cleaning where applicable, connections, brightness stages, CCR indications, equipment condition
      QuarterlyDetailed component inspection, connectors, transformer housings, CCR checks, control equipment, selected electrical measurements
      PeriodicDetailed system inspection, insulation and earthing checks, cable and circuit assessment, alignment and condition verification
      AnnualComprehensive inspection, electrical testing, photometric verification as applicable, documentation and plan review
      As requiredFault rectification, photometry, PAPI calibration or alignment, cable fault location, corrective maintenance, post-repair testing and retesting

      Typical schedule by AGL system

      SystemDailyWeeklyMonthly / periodicAnnual / detailed
      Runway edgeStatus, visualPhysical conditionConnections, fixturesDetailed inspection and performance verification
      Runway centrelineStatus, patternFixture conditionElectrical, physicalCircuit and photometric checks as required
      Taxiway lightsStatusFixture and sign inspectionElectrical, physicalDetailed system assessment
      Approach lightsStatus, patternStructural and fixturePhysical, electricalPhotometry and alignment as applicable
      PAPIOperational statusOptical, physicalAngle and electrical checks as specifiedCalibration and performance verification
      CCRAlarm, statusVisualBrightness, current, controlDetailed electrical and functional testing
      Isolating transformersOperational symptomsVisualPhysical, electricalDetailed condition assessment
      Cables and connectorsFault indicationsVisible conditionConnector and termination checksElectrical testing, fault-location investigation
      ALCMS / ILCMSAlarm, statusControl checkFunctional checksFull control and monitoring verification
      PhotometryAs required—Trend-basedScheduled or authority-defined
      Earthing and surge protectionFault indicationVisualInspection as specifiedDetailed test and verification

      What gets checked at each interval.

      MAINTENANCE FREQUENCY · EACH STEP UP GOES DEEPER AND CHECKS LESS OFTENDAILYVisual condition, status, reported faults, PAPI and signsWEEKLYFittings, cleanliness, connectors, exposed equipmentMONTHLYElectrical and physical inspection, brightness stages, CCR indicationsQUARTERLYComponent inspection, transformer housings, control equipment, selected measurementsPERIODICInsulation and earthing checks, cable and circuit assessment, alignmentANNUALComprehensive inspection, electrical testing, photometry, plan reviewAS REQUIRED · fault rectification, calibration or alignment, cable fault location, post-repair testingSCHEMATIC · ACTUAL INTERVALS COME FROM THE AIRPORT PROGRAMME, REGULATOR AND MANUFACTURER
      Figure 2. Frequency ladder from daily checks to the annual comprehensive inspection, with as-required work alongside.
      AGL Visual Encyclopedia: Inspection Requirement Flow Inspection Decision Flow
      Visual Aids

      Runway, Taxiway and Approach Lighting Maintenance

      Runway lighting

      Think in patterns, not fittings. Edge: output, colour, lens, alignment, mounting, frangibility, transformer. Centreline (inset): lens, cover, pavement interface, water ingress, continuity. Threshold, end and touchdown zone: colour, intensity, alignment, circuit continuity. The remaining serviceable lights must still preserve the intended pattern. ICAO guidance sets stricter serviceability objectives for CAT II/III systems and significant lighting elements.

      Taxiway lighting

      Keep guidance continuous and unambiguous: edge and centreline lights, inset and elevated fixtures, stop bars, guard lights, signs, connectors, transformers, foundations. Adjacent centreline failures can matter more than isolated ones, and ICAO-derived criteria include serviceability objectives for taxiway centreline lighting in low-RVR conditions. So classify defects by location and pattern, not just count.

      Approach lighting

      Maintain it as a geometric visual system: availability, intensity, colour, alignment, elevation, barrettes, crossbars, supports, frangible parts, cable and transformer connections, contamination and damage. Pay particular attention to the critical inner portions for high-category operations. ICAO material includes visual inspection plus in-field measurement of intensity, beam spread and orientation for precision approach lighting.

      Taxiway Lighting Maintenance Checklist

      A taxiway lighting maintenance checklist should keep guidance continuous and unambiguous, and defects should be classified by location and pattern, not just count. Adapt it to your approved programme and the frequencies in the AGL Maintenance Checklist further down this page.

      • Taxiway edge and centreline lights operational, with no abnormal pattern or adjacent centreline failures
      • Inset and elevated fixtures: lens condition, alignment, mounting, light base and water ingress
      • Stop bars, guard lights and signs checked
      • Connectors, isolating transformers, junction boxes and foundations inspected
      • Defects classified, closed or escalated, and recorded for trend analysis
      Taxiway lighting systems

      The order of a visual inspection of installed lighting.

      VIEW · FROM FAR TO NEAR start with the whole pattern, finish with the single component WHAT THE EYE LOOKS FOR every look has a defect it is trying to catch LAMP OUT DIM / UNEVEN 1. lit pattern from a distance 2. walk to each marked fixture 3. isolate, then open and look closer GAPS, DIMMING, WRONG COLOUR LIT out, dim, wrong colour, gaps EXTERNAL cracks, dirt, tilt, loose or missing fasteners SURROUNDINGS sealant, covers, water, debris, growth INTERNAL corrosion, damp, heat marks, damaged seals SIX INSPECTION STEPS · IN ORDER 1 PREPARE permit, records, last defects, PPE, radio with ATC 2 LIT VIEW circuit on: judge the pattern from a distance 3 WALK fixtures and signs one by one; note what is visible 4 SURROUNDS pavement, covers, water, debris, vegetation 5 CLOSE LOOK isolated, proved dead: connectors, seals, cable entries 6 RECORD classify, photo, log and raise work orders
      Figure 3. A fixed inspection sequence keeps checks repeatable and defects traceable to a location.
      AGL Visual Encyclopedia: Visual Inspection Sequence Fixture Inspection Fixture Cleaning
      A technician removing a taxiway light for inspection on an airfield at night
      Photo 1. Removing a taxiway light fitting for inspection. Inspection of fittings, seals and optics is a routine part of runway and taxiway maintenance.Credit: USAF photo by Staff Sgt. Stephenie Wade, 2013. Released public domain (US Government work). Original source
      PAPI and Electrical

      PAPI, CCR, Transformers, Cables and Connectors

      PAPI

      Beyond checking lamps are lit: optical (lenses, contamination, water ingress, deterioration), physical (housing, foundation, mounting, corrosion, fasteners), alignment (vertical angle, horizontal alignment, unit-to-unit relationship, elevation, relation to threshold and approved geometry), electrical (transformer, cables, connectors, supply, brightness operation, controls) and performance (white/red transition, beam, intensity, consistency, photometry). Consider calibration after significant maintenance, physical disturbance or changes that affect geometry. The AAI example includes PAPI angle checks with clinometers.

      Constant current regulator

      Inspect enclosure, ventilation, cooling, terminals, supply, output circuit, current indication, control interface, brightness stages, alarms, protection, switching devices, power electronics, communication modules, local and remote operation and status feedback. Where applicable verify output current and stability, each step, alarm response, remote command, circuit indication, changeover and fault reporting, against the CCR design, manufacturer documentation and airport specification, not one generic tolerance.

      Isolating transformers

      Check condition, primary and secondary connectors, leads, housing, moisture, corrosion, overheating, insulation condition, damage and connection security, plus the surrounding enclosure and drainage in housings and bases.

      Airport Lighting Cable Connector & Cable Maintenance

      Surface lamp failures can hide insulation breakdown, water ingress, damaged cable, connector failure, poor joints, transformer failure, earth leakage or discontinuity. Review cable identification and route records, joints, connectors, entry points, water ingress, insulation resistance, continuity, earth faults and fault-location results. Repeated failures at one location are a system-level defect, not repeated lamp replacement.

      Planned work before failure, step by step.

      ONE VISIT · ORDER OF WORK live look first, hands-on work only when isolated THE PLAN · FREQUENCY LAYERS quick checks often, deeper tests less often CIRCUIT LIVE look and report defects noted ISOLATED, PROVED DEAD clean, inspect tighten, replace test RESTORED re-energise verify lights record OUTAGE KEPT SHORT · TASKS GROUPED UNDER ONE ISOLATION FREQUENT walk-round, lights-out check PERIODIC cleaning, inspection, torque LONGER INTERVAL insulation, earth, CCR service TIME → INTERVALS SET BY THE SITE PROGRAMME, REGULATOR AND MAKER RECORDS AND TRENDS FEED THE NEXT PLAN SIX VISIT STEPS · IN ORDER 1 PLAN programme, permit, parts, tools; agree access and outage 2 LOOK circuit live: walk the lights, note what is wrong 3 ISOLATE circuit off, locked out, proved dead before hands-on 4 SERVICE clean, inspect, tighten, replace worn parts 5 TEST insulation, continuity and earthing before re-energising 6 RESTORE, LOG re-energise, verify lights, record and trend the results
      Figure 4. Preventive work on CCRs, transformers, cables and connectors follows a set sequence with testing before restoration.
      AGL Visual Encyclopedia: Preventive Maintenance Sequence CCR Maintenance Transformer Maintenance
      An airman using a multimeter to test voltage at a constant current regulator in an airfield lighting vault
      Photo 2. Testing a constant current regulator in an airfield lighting vault. Regulator checks and electrical measurements are part of scheduled CCR maintenance.Credit: USAF photo by Staff Sgt. Nick Wilson, 2013. Released public domain (US Government work). Original source
      Performance and Control

      Photometry, Control Systems, Surge Protection and LED

      Photometric verification

      A light can be electrically operational and no longer give the required optical performance. Photometry evaluates intensity, beam spread, colour, orientation, horizontal and vertical distribution, coverage, PAPI beam characteristics and brightness-stage performance. Trigger it at scheduled intervals, after major maintenance, rehabilitation, replacement or alignment work, after repeated failures, at commissioning and acceptance, when trends show degradation or when the authority requires it. A recent AAI tender covers runway, threshold, approach and PAPI/inset fittings with reports and corrective measures; that is project-specific, not a universal annual rule.

      Control and monitoring (ALCMS/ILCMS)

      Test both paths. Command: operator selects the circuit, the system sends the command, the CCR changes output. Feedback: the CCR changes state, the field status is detected, and the control system shows the correct status or alarm. Check local and remote control, circuit and CCR status, brightness command, alarm generation and acknowledgement, communication, event logs, loss-of-communication alarms and redundant paths. A wrong status indication can matter even when the lights work.

      Lightning and surge protection

      Inspect surge-protection devices, earthing and grounding, bonding, cabinets, CCR and control-system protection, cable-entry protection and visible damage. After a significant lightning event an unscheduled inspection may be appropriate even if the system seems fine.

      LED AGL

      LED cuts some lamp work but not maintenance. ICAO APAC working material highlights vibration, moisture and temperature issues. Inspect optical output, lens, housing, thermal condition, connectors, power supply, electronics, control interface, surge protection, moisture and alignment. An LED fitting that is "on" may still have degraded output.

      How a photometric test of an installed light is carried out.

      PHOTOMETRIC TESTING PROCESS · SEVEN STEPS, FROM MOUNTING TO REPORT 1 PREPARE Identify & mount 2 ALIGN Axis & centre 3 STABILISE Rated current 4 SCAN Grid, angle by angle 5 CHECK Repeat reference 6 RECORD Data table 7 REPORT Isocandela & report STEP 4 · SCANNING THE MEASUREMENT GRID · ONE READING PER GRID POINT HORIZONTAL ANGLE → VERTICAL ANGLE → INTENSITY TABLE H 0 / V 0 1850 cd H 2 / V 0 1420 cd H 0 / V 2 1610 cd H 2 / V 2 1180 cd EXAMPLE VALUES ONLY ISOCANDELA DIAGRAM & PHOTOMETRIC REPORT REPEAT A REFERENCE READING DURING AND AFTER THE SCAN DRIFT FOUND → REPEAT THAT PART, DO NOT REPORT IT RING = FINER SPACING NEAR THE PEAK COLOUR ALSO MEASURED FOR COLOURED LIGHTS SCHEMATIC · EXAMPLE VALUES ONLY · LIMITS FOLLOW THE STANDARD AND LABORATORY PROCEDURE
      Figure 5. Photometric verification confirms optical performance that visual inspection cannot see.
      AGL Visual Encyclopedia: Photometric Testing Process Photometric Inspection Photometric Testing Arrangement
      Triggers

      Event-Driven Maintenance

      A preventive programme should not run on calendar intervals alone. Trigger unscheduled inspection after lightning, heavy rainfall, flooding, severe storm, high winds, aircraft or vehicle excursion, construction, runway rehabilitation, pavement work, accidental damage, electrical incidents or unexplained alarms. A minor impact to an elevated light can change its orientation enough to affect photometric performance while it keeps working.

      Consider immediate or priority maintenance for

      Failure of a critical lightSeveral adjacent light failuresLoss of a required patternAbnormal CCR current or repeated alarmsPAPI displacement or inconsistent guidanceMajor cable fault or earth leakageDamaged connectorWater in critical equipmentImpact or lightning damageAbnormal photometric resultControl-system failure
      This matters most for precision approach and low-visibility operations, where ICAO sets serviceability objectives for different runway and operating conditions.

      From serviceability measurement to a maintenance action.

      RESULT TO ACTION FROM A SERVICEABILITY RESULT TO THE RIGHT RESPONSE 1 RESULT count and adjacency 2 COMPARE objective, action level 3 WHICH BAND? three responses below EXAMPLE: 60-LIGHT EDGE ROW, CAT II/III Objective 95% allows 3 out. Site action level: 2 out. The gap between 2 and 3 is the margin the flow protects. WITHIN OBJECTIVE 0 to 1 out, none adjacent LOG AND SCHEDULE repair at the next routine visit ROUTINE no notification needed ACTION LEVEL REACHED 2 to 3 out, none adjacent RAISE A WORK ORDER restore soon, spares on hand PLANNED, SOON tell control if the objective is at risk OBJECTIVE NOT MET 4+ out, adjacent pair, or critical light NOTIFY AND RESTORE NOW tell control first; restore one of a pair first URGENT control decides on operations THEN, FOR EVERY BAND RESTORE · RECHECK COUNT AND POSITIONS · LOG TIME FOUND AND RESTORED · REVIEW THE TREND The same circuit or fixture type failing again points to a cause, not a lamp. ICAO SETS THE OBJECTIVE. THE ACTION LEVEL IS THE OPERATOR'S OWN, SET ABOVE IT.
      Figure 6. Events such as lamp outages, strikes or works trigger maintenance outside the calendar.
      AGL Visual Encyclopedia: Serviceability-Triggered Maintenance Flow Minimum Serviceable Lamp Percentages by Light Type Closed Taxiway and Unserviceability Lighting
      Defects

      Defect Classification and Response

      ClassTypical meaningTypical response
      CriticalMay immediately compromise required guidance or system availabilityImmediate notification, operational assessment, urgent rectification
      MajorSignificant degradation of part of an important lighting systemPriority corrective maintenance
      MinorLocalized defect with limited immediate operational effectPlanned corrective maintenance
      ObservationNeeds monitoring but not immediate repairRecord and trend
      This is a maintenance-management classification, not a replacement for airport-specific operational criteria. Always weigh runway category, operating condition, defect location and applicable serviceability criteria.

      Critical examples

      Major runway circuit failure, loss of critical centreline guidance, PAPI not giving its guidance, serious CCR failure on an operational runway, widespread failure of a critical section, control failure where lighting cannot be reliably controlled or monitored.

      Major examples

      Multiple failed lights, repeated adjacent failures, significant brightness degradation, damaged transformer connection, water ingress affecting several fittings, damaged stop-bar section, significant PAPI alignment discrepancy.

      Minor examples

      Damaged hardware not affecting alignment, minor corrosion, localized lens contamination, non-critical sign damage, minor enclosure defects.

      Defect response process

      Detect
      Record
      Classify
      Assess operational impact
      Isolate if required
      Repair
      Test
      Verify
      Close
      Trend

      Record

      • Date, time, airport, runway or taxiway, location
      • Equipment ID and defect description
      • Photographs where useful
      • Operational status

      Assess, then verify

      • Does it affect guidance, a critical pattern, redundancy or electrical safety?
      • Does it need operational coordination, NOTAM or other notification under airport procedures?
      • After repair: light operates, circuit stable, pattern restored, control status correct, brightness and alignment correct, photometry met where applicable
      Do not close a defect simply because a replacement part was fitted. Test the completed work.

      From a reported defect to a verified repair.

      ONE FAULT · ORDER OF WORK assess first, locate while live, repair only when isolated FINDING IT · SPLIT THE LOOP test each part, keep halving until one part is left FAULT REPORTED, LIVE assess, prioritise locate from indications agree outage ISOLATED, PROVED DEAD split and test loop repair or replace test the repair RESTORED re-energise verify, record FAULT SPLIT 1 SPLIT 2 TESTS GOOD FAULT IN HERE GOOD each split halves the search at pits and connectors until one cable, joint or transformer remains SIX STEPS IN ORDER 1 REPORT alarm, patrol, call 2 ASSESS what, where, how urgent 3 LOCATE indications, then split 4 ISOLATE lock out, prove dead 5 REPAIR & TEST fix, then check 6 RESTORE & LOG verify, record cause FIND THE CAUSE, NOT JUST THE SYMPTOM · THE RECORD FEEDS THE PREVENTIVE PROGRAMME SCHEMATIC · NOT TO SCALE · RESPONSE TIMES AND LIMITS COME FROM THE SITE PROGRAMME AND STANDARD
      Figure 7. Defects are classified, then repaired, verified and restored in a fixed order.
      AGL Visual Encyclopedia: Corrective Maintenance Sequence Post-Maintenance Restoration Safe Maintenance Sequence
      Records

      Maintenance Records and Trend Analysis

      A good record holds

      • Asset: airport, runway or taxiway, system, circuit, equipment ID, fixture type, transformer ID, CCR number, location
      • Inspection: date, time, technician, conditions, type, test equipment
      • Defect: description, classification, operational impact, temporary and permanent action
      • Test: current, insulation and earth measurements, photometric and PAPI data, control test, calibration status
      • Closure: component replaced, repair, retest, supervisor verification, date

      Registers to maintain

      • Asset and maintenance registers
      • Testing and photometry registers
      • PAPI and CCR registers
      • Defect register (defect, class, impact, repair date, retest, closure)

      Reading the trends

      TrendPossible indication
      Repeated lamp failures at one locationFixture, transformer, connection or circuit problem
      Repeated transformer failuresMoisture, thermal or electrical stress
      Increasing cable faultsCable deterioration or water ingress
      Frequent CCR alarmsCCR or circuit abnormality
      Repeated PAPI realignmentFoundation, mounting or environmental issue
      Increasing photometric failuresOptical degradation or fixture ageing
      Repeated connector failuresSealing, installation or environmental problem
      Repeated water ingressDrainage, gasket or housing issue
      Trend analysis turns maintenance from failure replacement into asset-condition management.

      Why a trend over time says more than one reading.

      1 · THE TREND: READINGS AGAINST TIME 2 · COMPARABLE READINGS, THEN ACTION INSULATION RESISTANCE, MEGOHMS (LOG SCALE) 1000 100 10 BASELINE YR 1 YR 2 YR 3 YR 4 ALERT LEVEL MINIMUM (SPEC) SOUND: FLAT, SEASONAL WIGGLE SLOW DECLINE: ACT AT THE ALERT LEVEL SUDDEN STEP: A NEW FAULT PLOT EVERY READING OF EVERY CIRCUIT AGAINST ITS BASELINE TREND = SLOPE + STEPS, NOT ONE NUMBER A PASS TODAY CAN STILL BE A CIRCUIT HEADING FOR FAILURE KEEP EVERY READING COMPARABLE SAME TEST VOLTAGE AND SAME TIME TO READING SAME CIRCUIT SECTION AND SAME TEST POINT SAME TESTER, IN CALIBRATION CORRECT TO A REFERENCE TEMPERATURE NOTE THE WEATHER, MOISTURE AND CABLE ENDS CCR LOCKED OUT AND DISCONNECTED ACTION LADDER FLAT OR SEASONAL: KEEP THE ROUTINE INTERVAL FALLING TOWARD ALERT: RETEST SOONER, SPLIT LOOP STEP DROP OR BELOW MINIMUM: LOCATE AND REPAIR COMPARE CORRECTED READINGS TO THE BASELINE R(ref) = R(measured) × 2^((T − Tref) ÷ 10) RULE OF THUMB: RESISTANCE ROUGHLY HALVES PER 10 °C RISE USE THE CORRECTION TABLE FOR THE CABLE TYPE BASELINE · SAME CONDITIONS · CORRECT FOR TEMPERATURE · PLOT · READ THE SLOPE · SET AN ALERT LEVEL · ACT EARLY
      Figure 8. Recording measurements over time shows slow degradation before it becomes a fault.
      AGL Visual Encyclopedia: Insulation-Resistance Trend Analysis Over Time Insulation-Resistance Testing As-Built Records and Circuit Schedules
      Approach

      Preventive, Corrective and Condition-Based Maintenance

      Preventive

      Planned work before failure: cleaning, scheduled inspection, tightening, electrical testing, alignment checks, photometry, connector, transformer and CCR checks.

      Corrective

      Work after a defect: replacing failed fittings, transformers or connectors, cable repair, PAPI realignment, CCR repair, sign replacement, repair after impact.

      Two airports with the same AGL equipment can need very different programmes because of aircraft movements, climate, rainfall, humidity, dust, salt, pavement condition, flooding, lightning exposure, installation age, LED technology, runway category, operating hours, RVR conditions and fault history. The best programmes combine time-based, condition-based and event-driven maintenance: annual photometry, find degradation, raise inspection frequency, clean, repair or replace, retest, trend.

      Seven layers a programme must protect

      AvailabilityElectrical integrityOptical performanceGeometric performancePattern continuityMonitoring integrityDocumentation
      A programme that checks only lamp operation is incomplete.

      Time, condition and events all trigger work, and all feed one loop.

      ONE PROGRAMME · THREE TRIGGERS · ONE LOOPTIME-BASEDScheduled by calendarCONDITION-BASEDTriggered by measured degradationEVENT-DRIVENTriggered by storm, strike, impact, worksFIND DEGRADATIONRAISE INSPECTIONCLEAN / REPAIRRETESTTRENDTREND FEEDS THE NEXT INSPECTION INTERVALSCHEMATIC · A PROGRAMME THAT CHECKS ONLY LAMP OPERATION IS INCOMPLETE
      Figure 9. The best programmes combine time-based, condition-based and event-driven maintenance in one loop.
      AGL Visual Encyclopedia: Predictive Maintenance Preventive Maintenance Sequence Corrective Maintenance Sequence
      Checklists

      AGL Maintenance Checklist

      Click an item to mark it complete. Use as a sample and adapt to your approved programme.

      Daily

      Required runway lights operational
      Failed fittings identified; no obvious damage
      No abnormal lighting pattern
      Threshold, end, centreline and touchdown zone checked where applicable
      Taxiway edge and centreline lighting operational
      Stop bars and signs checked
      PAPI units operational, lenses clean, no displacement
      CCR and control-system status normal; no unexplained alarms
      0 / 8 complete

      Weekly

      Detailed fixture inspection and lens condition
      Sign and PAPI condition
      Visible connector condition
      Light-base and transformer-housing condition
      Water ingress and corrosion check
      Reported defects closed or escalated
      0 / 6 complete

      Monthly

      Internal optical cleaning where applicable
      Electrical connections inspected
      CCR brightness stages and output current reviewed
      Transformer condition and junction boxes checked
      PAPI alignment checks as required
      Equipment foundations inspected
      Control-system operation checked
      0 / 7 complete

      Quarterly

      Detailed CCR inspection
      Cable and connector review
      Isolating transformer inspection
      Earthing and grounding inspection where scheduled
      Surge protection inspection
      Control-system alarms tested
      Equipment trends reviewed; repeat defects analysed
      0 / 7 complete

      Annual / periodic

      Complete AGL system inspection
      Electrical, insulation and earthing tests where applicable
      Photometric testing as required
      PAPI calibration and alignment as required
      CCR performance verification
      Control-system functional test
      Cable fault investigation where indicated
      Maintenance history, asset condition and spares reviewed
      Preventive-maintenance programme reviewed
      0 / 9 complete

      Airport Lighting Inspection Checklist

      The checklist above sets out the inspection items by frequency, from the daily operational check to the annual or periodic inspection. Adapt it to the aerodrome's approved programme and record the result of each inspection, including any defect and its closure.

      Airport Lighting Day Inspection

      A day inspection is the physical check: damaged or displaced fittings, cracked or contaminated lenses, water ingress, exposed wiring, damaged bases or covers, corrosion, mounting and foreign material around the fittings, plus the condition of signs and PAPI units.

      Airport Lighting Night Inspection

      A night inspection checks the lighting while it is lit. Failed or intermittent lights, abnormal brightness or colour, an abnormal lighting pattern and the PAPI indications are easier to see at night, so it complements the day inspection rather than replacing it.

      India and Contracts

      Maintenance in India and Contractor Scope

      For Indian airports, align the programme with applicable DGCA requirements, AAI requirements where they apply, current AIP/eAIP information, approved airport procedures, equipment manuals and project specifications. A current AAI eAIP entry assigns the Electrical In-charge responsibility for Category I precision-approach lighting serviceability and states the associated runway-lighting serviceability objective. AAI maintenance documents show practical schedules mixing daily cleaning and serviceability checks, periodic PAPI angle checks, brightness-stage checks, CCR operation, wiring and termination inspection and earthing records. Do not copy a generic monthly or annual checklist: build the programme from the actual configuration and requirements.

      Runway Lighting Standards India

      For runway lighting in India, the applicable requirements come from DGCA requirements, AAI requirements where they apply, current AIP/eAIP information, approved airport procedures, equipment manuals and the project specification. There is no single generic standard set for every runway, so identify the requirements from the airport's own documents. See the Standards Companion for how the references fit together.

      Airport Lighting Test Standards

      The standard used for a test depends on what is being tested. Electrical tests follow the equipment manufacturer's documentation and the project specification, and photometric tests follow the requirement the aerodrome or authority defines. Do not use one generic tolerance, and record the test equipment and its calibration status with the result.

      A contractor scope should define

      • Inspection frequency and working hours
      • Airside access, safety and permit requirements
      • Equipment to inspect, test instruments and calibration
      • Spare parts and emergency response
      • Defect response time
      • Documentation and reporting
      • Photometric testing and PAPI calibration
      • CCR maintenance and transformer inspection
      • Cable fault location and post-maintenance testing
      • Final acceptance, and what counts as routine, preventive, corrective, specialized testing or major rehabilitation
      Service Scope

      Maintenance Services by Precision AGL Solutions

      One coordinated process, from inspection to trend analysis, subject to the airport’s scope, approved procedures and applicable authority requirements.

      Field inspectionElectrical testingPhotometryPAPI alignmentCCR checksTransformer inspectionCable and connector assessmentCorrective maintenanceMaintenance documentation
      Inspection

      Measurement

      Diagnosis

      Corrective action

      Retesting

      Records

      Trend analysis

      Final Engineering Perspective

      An airport lighting maintenance schedule is a planned asset-management system across the whole chain: fixture, transformer, connector, cable, CCR, control system, photometric performance and documentation.

      Inspect. Measure. Diagnose. Correct. Retest. Record. Trend.

      Test Yourself

      Quick Knowledge Check

      Q1. What should set the final maintenance frequency?

      A. One generic calendar
      B. The approved programme, regulations, runway category, OEM instructions and asset-condition history
      C. Whatever the last airport used
      D. Lamp count

      Q2. A control system should be tested for which paths?

      A. Command only
      B. Feedback only
      C. Both command and feedback
      D. Neither

      Q3. A defect keeps recurring at one location. What is the right view?

      A. Keep replacing the lamp
      B. A system-level defect to investigate
      C. Ignore it
      D. Increase brightness

      Q4. When can a defect be closed?

      A. When a part is fitted
      B. After the completed work is tested and verified
      C. After a day
      D. When reported

      Q5. Which classification suits a localized lens contamination with limited operational effect?

      A. Critical
      B. Major
      C. Minor
      D. None
      Explore More

      Explore More AGL Engineering

      HANDBOOK

      Maintenance Handbook

      The AGL maintenance reference.

      Open Maintenance Handbook →
      TESTING

      AGL Photometric Testing Procedure

      Field procedure for photometry.

      Open AGL Photometric Testing Procedure →
      PERFORMANCE

      AGL Photometry

      Photometry concepts and reporting.

      Open AGL Photometry →
      ELECTRICAL

      CCR Working Principle

      Series circuits and current steps.

      Open CCR Working Principle →
      ELECTRICAL

      Airport Isolating Transformer

      Ratings, types and testing.

      Open Airport Isolating Transformer →
      HARDWARE

      Junction Boxes & Transformer Housings

      Light bases and housings.

      Open Junction Boxes & Transformer Housings →
      VISUAL AID

      PAPI Alignment & Maintenance

      PAPI alignment and field practice.

      Open PAPI Alignment & Maintenance →
      HUB

      AGL Components

      Electrical, lighting, mechanical and control components.

      Open AGL Components →
      CHECKLIST

      PAPI Maintenance Checklist

      Inspection, testing and troubleshooting.

      Open PAPI Maintenance Checklist →
      PAPI

      PAPI Calibration, Aiming & Alignment

      Angle, alignment and unit geometry.

      Open PAPI Calibration, Aiming & Alignment →
      TESTING

      Testing & Commissioning Guide

      Test and commission AGL systems.

      Open Testing & Commissioning Guide →
      PROTECTION

      Lightning & Surge Protection

      Counterpoise, bonding and SPDs.

      Open Lightning & Surge Protection →
      SYSTEM

      How Airfield Lighting Works

      From power to optical output.

      Open How Airfield Lighting Works →
      STANDARDS

      ICAO Aerodrome Lighting Requirements

      The ICAO AGL framework.

      Open ICAO Aerodrome Lighting Requirements →

      Maintain the Whole Chain.

      From daily checks to trend analysis, explore the complete AGL knowledge base.

      AGL Engineering Hub

      Explore the AGL Engineering Knowledge Hub

      Fundamentals

      Standards & Compliance

      Runway, Taxiway & Approach Lighting

      Surface Movement & Safety

      PAPI

      Electrical Engineering & Power

      Photometry & Testing

      Maintenance, Inspection & Safety

      Resources, Documentation & Careers

      FAQ

      Airport Lighting Maintenance FAQ

      Q1How often should airport lighting be maintained?

      There is no single universal calendar. Base AGL maintenance on the aerodrome's approved preventive-maintenance programme, operating category, equipment type, manufacturer requirements and authority requirements. A practical programme combines daily or operational checks with weekly, monthly, periodic and annual inspections.

      Q2Is airport lighting inspected every day?

      Operational inspections are commonly daily or per shift, but the exact requirement depends on the approved aerodrome procedures. Daily checks focus on serviceability, visible damage, reported faults and operational condition.

      Q3How often should PAPI be checked?

      According to the approved maintenance programme. Routine checks can cover optical cleanliness, physical condition, electrical operation and alignment. Some AAI maintenance schedules specify more frequent PAPI angle checks than a simple monthly inspection, so project-specific requirements can be more demanding than a generic schedule.

      Q4How often should airport lighting photometry be performed?

      There is no single interval for every installation. Photometry may be scheduled periodically and also triggered by commissioning, rehabilitation, alignment changes, fixture replacement, repeated defects or performance concerns. The airport specification and maintenance programme decide the interval.

      Q5What is preventive maintenance in airport lighting?

      Planned work done to reduce the probability of failure or degradation: inspection, cleaning, testing, alignment, electrical checks, photometry, component inspection and similar activities.

      Q6What is corrective maintenance in AGL?

      Work done after a defect is identified, such as replacing failed fittings, repairing cables, replacing isolating transformers, repairing CCRs and realigning PAPI.

      Q7Why is AGL cable maintenance important?

      AGL is an electrical distribution system, not independent lamps. Cable, connector and transformer problems can cause repeated light failures and circuit instability, so the programme should include the associated cable systems. FAA preventive-maintenance guidance includes cable systems.

      Q8Should LED airport lighting still be maintained?

      Yes. LED reduces lamp replacement but still needs inspection of optical output, electronics, thermal condition, connectors, housing, surge protection, moisture ingress and alignment.

      Q9What should happen after an AGL repair?

      Test the repaired equipment before closing the defect. Depending on the repair, that may be electrical testing, operational testing, control-system verification, alignment checks or photometric verification.

      Q10What is the difference between AGL maintenance and AGL testing?

      Maintenance restores or preserves equipment condition. Testing measures and verifies performance. A good programme uses both.

      Q11Why are maintenance records important?

      They show what was inspected and tested, evidence defect closure, support audits and enable trend analysis that can expose recurring problems before they become major failures.

      Field Insight

      Engineering & Expert Notes

      Adapt Frequencies to Your Own Experience
      Planning

      Generic schedules are a starting point. Adjust intervals using failure history, traffic and environment.

      Night Inspections Reveal What Day Checks Miss
      Inspection

      Dimmed or misaligned lights and colour issues are more obvious in darkness. Include night checks in the schedule.

      Classify Defects for Consistent Response
      Defects

      Define response times for categories of defect so crews and managers share expectations.

      Use Records to Spot Trends
      Trends

      Repeated failures in one area point to a systemic cause. Review logs regularly and act on patterns.

      Schedule Electrical and Photometric Checks, Not Only Visual Ones
      Coverage

      A visual walk does not show insulation decline or optical drift. Plan instrument-based checks too.

      Close the Work Order Fully
      Records

      Record what was found and done so that the next visit starts from facts.

      Precision AGL Academy

      Understand AGL. Build Your Engineering Skills.

      You now understand how to plan airport lighting maintenance, from daily checks to annual inspection, with defect classification, records and trend analysis.

      Take the next step with Precision AGL Academy.

      Learn AGL Step by Step

      Build your knowledge through structured technical learning covering:

      AGL Fundamentals Components Electrical Systems Design Photometry Testing Troubleshooting Maintenance

      Move from understanding how AGL works to developing the practical knowledge needed to analyse, operate and maintain complete AGL systems.

      Understand the system. Build the knowledge. Apply the engineering.