Airport Lighting Maintenance, Inspection & Fault Finding
The 30 divisions below hold the detailed fault topics. This guide shows how they fit into day-to-day AGL work: finding a fault, inspecting the field, keeping to a maintenance schedule and replacing failed lights. Each block links to the divisions that carry the full diagnostic records.
Airport Lighting Fault Finding, Fault Diagnosis & Fault Detection
Airport lighting fault finding starts with the symptom and works inward: which lights are out, on which circuit, at which brightness step. Airport lighting fault diagnosis then narrows that symptom to a section of the circuit using CCR readings, insulation resistance and continuity checks. Airport lighting fault detection is what flags the problem in the first place, through ALCMS alarms, CCR output monitoring and field inspection.
- Emergency quick-diagnosis for a fast first response
- Diagnostic decision trees for step-by-step fault location
- Series circuit electrical faults for earth faults and open circuits
AGL Fault Testing
AGL fault testing follows a fixed order: confirm the CCR output, check the circuit for earth leakage, then isolate the faulty section by splitting the loop.
Airport Lighting Fault Monitoring & the Fault Monitor
Airport lighting fault monitoring relies on the control and monitoring system to report lamp-out counts, circuit current, earth-fault status and CCR alarms to the tower and maintenance room. An airport lighting fault monitor is the unit or software function that collects these signals and raises the alarm when a threshold is crossed.
Monitoring tells you that a fault exists and roughly where. It does not replace a field check, so alarms should always be confirmed on site.
- ALCMS / control & monitoring
- Difficult / intermittent faults when alarms come and go
Runway Lighting Common Faults & Runway Lighting Partial Failure
Runway lighting common faults include lamp failure, cracked or flooded fixtures, damaged connectors, isolating transformer failure, cable insulation breakdown and CCR faults. A runway lighting partial failure means some lights on a circuit are out while others stay lit, which usually points to individual lamps, transformers or connectors rather than the CCR.
What Causes Runway Light Failure?
When people ask what causes runway light failure, the usual answers are moisture ingress, lamp ageing, connector damage, surge and lightning damage, cable faults and aircraft or vehicle impact. A whole circuit going dark points to the CCR, the main cable or an open circuit.
Runway Lighting Troubleshooting Guide
For a complete runway lighting troubleshooting guide, start with the divisions below, which cover each light type in the runway system.
What Causes Taxiway Light Failure?
The causes of taxiway light failure are similar to runway lights but with more damage from ground vehicles, aircraft wheel loads and jet blast. Typical causes are water in the fixture, lamp burnout, damaged base can or connector, failed isolating transformer and cable damage from excavation.
Blue edge lights and green centreline lights can also lose colour or intensity from dirty lenses or a worn filter, so a light that is on but dim still counts as a fault.
Airport Lighting Night & Day Inspection, Periodic Inspection & Inspection Report
An airport lighting night inspection checks what only shows when the lights are on: outages, uneven brightness, wrong colour, misaligned or obscured lights. An airport lighting day inspection checks the physical condition: lenses, fixtures, base cans, covers, signs, paint, drainage and vegetation.
The same split applies to specific areas. Runway lighting night inspection and runway lighting day inspection cover runway edge, threshold, centreline and touchdown lights, and approach lighting night inspection covers the approach bars and lamps from the air side and, where permitted, from an aircraft or vehicle.
AGL Periodic Inspection & AGL Inspection Report
AGL periodic inspection covers scheduled checks at set intervals set by the aerodrome operator and regulator. Each one should end in an AGL inspection report that records date, area, defects found, action taken and who signed it off.
AGL Testing, Inspection & Maintenance Checklists
A good checklist keeps the work repeatable between technicians and shifts. The Atlas checklist library is the place to start. Typical checklist types are:
- AGL testing checklist and airport lighting testing checklist: CCR output, insulation resistance, continuity, earth checks and brightness steps
- Airport lighting inspection checklist: visual condition and lamp status across the airfield
Runway Lighting Checklist & Taxiway Lighting Checklist
- Runway lighting checklist, with a runway lighting inspection checklist, runway lighting maintenance checklist and runway lighting commissioning checklist for each stage of the equipment life
- Taxiway lighting checklist, with a taxiway lighting inspection checklist, taxiway lighting maintenance checklist and taxiway lighting commissioning checklist
Approach Lighting Checklist & PAPI Maintenance Checklist
- Approach lighting checklist and approach lighting maintenance checklist
- PAPI maintenance checklist: alignment, lens condition, lamp and heater checks
What is an AGL maintenance checklist? See the answer in the FAQ below.
Maintenance Types & Schedule: Preventive, Corrective, Emergency & Breakdown
An airport lighting maintenance schedule sets out what is checked daily, weekly, monthly and yearly. Airport lighting preventive maintenance follows that schedule to catch wear before it causes an outage: cleaning, torque checks, insulation tests and lamp changes.
Airport lighting corrective maintenance fixes a known defect on a planned job. Airport lighting emergency maintenance and airport lighting breakdown maintenance deal with failures that affect operations and need an immediate response, often under a NOTAM or reduced-visibility restrictions.
- Preventive troubleshooting
- Emergency quick-diagnosis
- CAT I / II / III troubleshooting for low-visibility requirements
Airport Lighting Replacement Procedure
An airport lighting replacement procedure follows the same safe order in every case: get permission and isolate the circuit, lock out and earth the CCR output, prove it dead, replace the part, test, and restore with approval from control.
Runway Light Replacement, Taxiway Light Replacement & Approach Lighting Replacement
- Runway light replacement: match the fixture type, lamp and filter; check the seal, torque and alignment
- Taxiway light replacement: check colour, lens orientation and base can condition
- Approach lighting replacement: replace the fixture or lamp, then check aiming and frangible mounting
- Runway light maintenance procedure: clean, inspect, test and record on every visit, not only when replacing
Never work on a live series circuit. The current in a series loop can stay present even when lights look off.
AGL Maintenance Technician & Maintenance Training
An airport lighting maintenance technician needs to understand series circuits, CCR operation, high-voltage safety, test equipment and the aerodrome's operating procedures. AGL maintenance training should cover both theory and hands-on fault finding, and be kept current as equipment changes.