AGL Testing & Inspection
A practical testing, inspection and verification guide for Airfield Ground Lighting. AGL testing and inspection is the process of confirming that lighting equipment and systems are physically sound, electrically safe, mechanically correct, operationally functional and optically compliant — from the power source to the final optical output.
What Is AGL Testing & Inspection?
AGL Inspection is the systematic examination of equipment, installation, components and physical conditions.
AGL Testing is the measurement or functional verification of defined electrical, mechanical, optical or operational parameters.
Together they answer one question: is the AGL system installed correctly, electrically healthy, mechanically sound and capable of providing the required visual performance?
Not Just "Is It ON?"
AGL testing should not be limited to checking whether a light illuminates. A complete program examines the system from the power source to the final optical output.
Four Verification Areas
A practical framework separates verification into electrical, mechanical, optical and operational dimensions — together forming complete AGL verification.
Traceable Evidence
Every inspection and test should be recorded so the system's condition and performance can be demonstrated, trended and defended.
A System May Look Normal While Having an Underlying Defect
AGL systems operate in demanding environments and may experience a wide range of degrading conditions. Testing helps identify problems before they become operational failures.
Four Dimensions of AGL Verification
A practical AGL inspection framework can be divided into four major areas. Electrical + Mechanical + Optical + Operational = Complete AGL Verification.
1. Electrical
Is the electrical system healthy?
2. Mechanical
Is the physical installation secure and correctly positioned?
3. Optical
Is the light producing the required visual performance?
4. Operational
Does the complete system operate and respond correctly?
AGL Testing Hierarchy
A useful testing sequence helps prevent unnecessary energization of defective equipment.
When Should AGL Testing Be Performed?
The exact testing frequency should follow the applicable airport maintenance program, standards and project requirements. Testing and inspection may be required during:
Incoming Material Inspection
Testing starts before installation. Inspect incoming equipment thoroughly.
Inspect Incoming Equipment For
- Correct model
- Correct rating
- Correct quantity
- Correct accessories
- Physical damage
- Manufacturing defects
- Identification
- Certification
- Packaging condition
- Storage condition
Typical Equipment
Visual & Mechanical Inspection
Visual inspection is the first line of AGL quality control and should be documented rather than treated as an informal walk-through. Mechanical inspection then verifies the physical integrity of the installation.
Visual Inspection — Check For
- Broken housing
- Cracks
- Corrosion
- Loose hardware
- Missing covers
- Damaged lenses
- Dirty optics
- Water ingress
- Cable damage
- Connector damage
- Incorrect installation
- Missing identification
- Physical obstruction
Mechanical Inspection — Verify
Fixtures
Transformers
Signs
PAPI
Visual inspection in six steps.
AGL Visual Encyclopedia: Visual inspection sequence Mechanical inspection Fixture inspection
Fixtures, Transformers, Connectors & Cable
Component defects are a common source of intermittent AGL faults. Record defects by fixture location and inspect each component category on its own merits.
AGL Fixture Inspection
- Housing, lens, optical surfaces
- Fasteners & mounting base
- Frangible fittings
- Cable connection & connector
- Sealing & drainage
- Orientation
Inset Light Inspection
- Fixture elevation
- Surface condition
- Mounting, lens, gaskets
- Sealing & drainage
- Cable connection & connector
- Mechanical damage
Elevated Light Inspection
- Base, pole/stem
- Frangible fitting
- Fixture head & mounting bolts
- Orientation & stability
- Cable & connector
- Blast/vehicle damage
Isolation Transformer Inspection
- Rating & identification
- Housing & connector
- Water ingress
- Physical damage
- Insulation condition
- Installation position matches design
Connector Inspection
- Correct type & mating
- Mechanical locking
- Contact condition
- Cable termination
- Water ingress & corrosion
- Strain relief
Cable Inspection
- Route & identification
- Physical damage
- Joint condition & termination
- Mechanical protection
- Water exposure
- Signs of overheating
Electrical Testing
Electrical testing is one of the most important pillars of AGL verification. The exact test method and acceptance value must be taken from the applicable equipment standard, manufacturer instructions and project specification.
Continuity & Insulation Resistance Testing
Continuity Test
Verifies that the intended electrical path is complete. For a series circuit, the engineer may verify the circuit path through:
CCR → Cable → Transformer → Connector → Fixture → Transformer → Cable → CCR
Record circuit number, test points, test instrument, measured result, acceptance criterion and PASS/FAIL.
Insulation Resistance Test
Can identify moisture, damaged insulation, cable deterioration, ground leakage, incorrect termination and connector problems.
Testing should be performed using the specified test voltage and procedure. Sensitive electronic equipment should be isolated where required by the manufacturer before applying insulation-test voltage.
Continuity is verified around the complete series loop — a numbered test point at each stage keeps the result traceable back to a specific segment
Cable Testing & Isolation Transformer Testing
Cable Testing — By Stage
Before Installation
Visual condition, drum condition, cable identification.
During Installation
Physical damage, routing, termination.
Before Energization
Continuity, insulation resistance, circuit identification.
After Repair
Repeat applicable electrical tests — a repaired cable should not be returned to service without verification.
Isolation Transformer Testing
Depending on the applicable procedure, inspect/test:
- Primary continuity
- Secondary continuity
- Insulation
- Physical condition
- Connector condition
- Rating & identification
Coordinate with the applicable manufacturer and project requirements.
CCR Testing
CCR testing is one of the most important AGL system tests, covering input, output, control and monitoring functions.
Input
Supply voltage, phase condition where applicable, protection.
Output
Output current, current stability, intensity steps, circuit response.
Control
Local control, remote control, ON/OFF, intensity selection.
Monitoring
Fault indication, alarm, circuit monitoring, communication where applicable.
CCR Output Current Test Record
| Step | Set Value | Measured Value | Status |
|---|---|---|---|
| Step 1 | As specified | Measured | PASS/FAIL |
| Step 2 | As specified | Measured | PASS/FAIL |
| Step 3 | As specified | Measured | PASS/FAIL |
| Step 4 | As specified | Measured | PASS/FAIL |
| Step 5 | As specified | Measured | PASS/FAIL |
A CCR on test, with six checks.
AGL Visual Encyclopedia: CCR testing CCR inspection CCR protection
Circuit Monitoring, Voltage & Earthing
Circuit Current Monitoring
Compare actual circuit current against expected system performance. Abnormal current may indicate:
- Short circuit
- Incorrect load
- Transformer problem
- Fixture failure
- Cable problem
- Incorrect connection
- Circuit configuration error
Voltage Measurement & Earthing
Possible measurement points: CCR input/output, transformer input/output, equipment supply. Consider nominal voltage, operating voltage, variation and drop.
Earthing & bonding: equipment grounding, panel grounding, bonding, metal structures, cable protection, PAPI/sign grounding, surge protection. Test earth continuity and earth resistance where required.
The current is the same everywhere on a healthy series loop — where the clamp reading departs from the expected value narrows down which segment to investigate
Functional Testing
Functional testing verifies actual operation, and the test should reproduce the intended operating conditions.
Five operating checks on the live system.
AGL Visual Encyclopedia: Functional testing Commissioning sequence Load testing
Runway, Taxiway, Approach, PAPI & Sign Inspection
Approach lighting and PAPI should be inspected as complete visual systems — verifying both physical and operational condition, not just individual fixtures.
Runway Lighting
Edge lights, centreline, threshold, runway end and touchdown zone lights.
- Location & spacing
- Orientation, colour, intensity
- Circuit operation
- Physical condition
Taxiway Lighting
Edge, centreline, stop bars, runway guard, lead-on/off and intersection lighting.
- Physical condition
- Operational condition
Approach Lighting
Fixture position, structure, elevation, alignment, output, sequencing and colour.
- Cable, transformer, connector
- Control
PAPI Inspection & Testing
Mechanical
Foundation, position, elevation, mounting, frangibility.
Electrical
Supply, current, cable, connector, earthing.
Optical
Aiming, alignment, colour, intensity, photometric performance.
Airfield Sign Testing
- Legend, location, orientation
- Structure & illumination
- Brightness & power
- Control & monitoring
- Photometric performance where applicable
Verify the installed legend matches the approved sign schedule.
Six stages of an inspection.
AGL Visual Encyclopedia: Inspection requirement flow Inspection decision flow PAPI inspection Sign inspection
Optical Inspection & Photometry
Optical Inspection
Evaluates the visual condition of the light. Check the lens, reflector, optical chamber, LED module, lamp, colour, contamination, damage and condensation.
Optical contamination can reduce performance even when the electrical system remains healthy.
AGL Photometry
Provides quantitative verification of optical performance — intensity, distribution, colour, beam characteristics, alignment and uniformity — using suitable calibrated equipment and the applicable measurement procedure.
Open the full AGL Photometry guide →The electrical circuit only proves the lamp is energized — contamination, damage or a shifted reflector between the source and the beam still reduces the light actually delivered
Electrical Testing vs Photometry, Inspection vs Testing
A system can pass electrical testing and fail photometry. Both inspection and testing are required — inspection identifies visible problems, testing identifies measurable problems.
| Electrical Testing | Photometry |
|---|---|
| Checks power | Checks optical output |
| Measures voltage/current | Measures light |
| Checks insulation | Checks intensity |
| Checks continuity | Checks distribution |
| Checks electrical health | Checks visual performance |
| Finds cable faults | Finds optical deficiencies |
| Inspection | Testing |
|---|---|
| Looks for visible defects | Measures performance |
| Housing condition | Electrical values |
| Lens condition | Insulation |
| Cable damage | Continuity |
| Mounting | Current |
| Corrosion | Voltage |
| Water ingress | Photometry |
Testing by Equipment
| Equipment | Typical Verification |
|---|---|
| CCR | Input, output current, steps, control, monitoring |
| Series circuit | Continuity, insulation, current |
| Isolation transformer | Rating, condition, continuity, insulation |
| Connector | Condition, mating, termination |
| Runway light | Physical, electrical, optical |
| Taxiway light | Physical, electrical, optical |
| Approach light | Position, alignment, electrical, optical |
| PAPI | Position, elevation, alignment, electrical, optical |
| Sign | Legend, structure, electrical, illumination |
| Cable | Continuity, insulation, physical condition |
| Earthing | Continuity and applicable earth measurements |
AGL Inspection Frequency
The actual frequency should be defined by the airport's approved maintenance program and applicable requirements.
Routine Inspection
Regular visual inspection during normal airport operations/maintenance.
Detailed Inspection
More comprehensive equipment and installation inspection.
Electrical Testing
Scheduled testing of cables, circuits and equipment.
Photometric Inspection
Periodic measurement of optical performance as required.
Special Inspection
Triggered by an event — see the cards below.
Special Inspection After an Event
Click a card to see what to check.
After Lightning
Inspect & Look For
- CCR, control system, surge protection
- Cables, transformers, fixtures, PAPI, signs, earthing, monitoring
- Burn marks, electronic failure
- Insulation damage, abnormal current
- Multiple fixture failures
After Heavy Rain / Flooding
Check For
- Water ingress, flooded transformer pits
- Cable insulation deterioration
- Connector moisture, fixture condensation
- Damaged seals, corrosion, earthing problems
After Fixture Replacement
Verify Sequence
- Correct fixture → correct transformer → correct connector
- Correct installation → electrical test → functional test
- Alignment → photometry where applicable
After Cable Repair
Nine-Step Sequence
- Inspect the repair
- Verify termination
- Verify continuity
- Verify insulation
- Verify circuit condition
- Energize under controlled conditions
- Verify current
- Inspect fixtures
- Record results
Test Instruments & Result Recording
A measurement without traceability has limited engineering value. All measurement equipment should be suitable for the application and maintained/calibrated according to the applicable quality system.
Typical AGL Test Instruments
For Every Important Measurement, Record
- Instrument name & ID
- Model & serial number
- Calibration status & due date
- Test range
- Test date & technician
Test Result Record — Required Fields
| Field | Requirement |
|---|---|
| Project | Airport/project name |
| Location | Exact location |
| Equipment | Equipment under test |
| Circuit | Circuit number |
| Test | Test performed |
| Instrument | Instrument ID |
| Requirement | Applicable criterion |
| Result | Measured value |
| Status | PASS/FAIL |
| Technician | Person performing test |
| Date | Test date |
| Remarks | Additional information |
PASS / FAIL Philosophy & Defect Classification
A test result should be compared with a defined acceptance criterion. Avoid declaring PASS merely because the equipment appears operational.
PASS
Measured result satisfies the applicable requirement.
FAIL
Measured result does not satisfy the applicable requirement.
HOLD / INVESTIGATION
Result is abnormal, inconclusive or requires additional investigation.
Defect Classification
Potential impact on operational safety or major system availability.
Significant equipment or system defect requiring corrective action.
Defect that does not immediately prevent operation but requires correction.
Condition requiring monitoring or future action.
Defect → Test → Rectification → Re-Test
AGL Testing Troubleshooting Logic
When a test fails, work through the sequence below. This prevents incorrect component replacement.
Confirm the Test Method
Confirm the Test Instrument
Repeat the Measurement
Compare with Historical Results
Check Upstream Equipment
Check the Circuit
Check the Individual Component
Rectify the Cause
Re-Test
Historical Test Data & Documentation
Historical Test Data — Track
Trend analysis can reveal deterioration before complete failure occurs.
A Complete Testing File May Include
- Inspection checklists
- Electrical, cable, transformer & CCR test reports
- Earthing reports
- Functional test reports
- Alignment records & photometry reports
- Calibration certificates
- Defect reports & re-test records
- Final acceptance records
AGL Circuit Resistance, Continuity Test & Insulation Resistance Test
The core electrical checks on an airfield lighting series circuit, and what a poor result usually means.
AGL circuit resistance
AGL circuit resistance is the total resistance of the series loop, from the CCR output, through the primary cable and connections, and back. It is compared with the expected value from the cable length and size. A reading that is much higher than expected can point to a poor joint, a damaged conductor or a loose connection. Acceptance limits come from the project specification.
AGL circuit continuity test
An AGL circuit continuity test confirms that the series loop is complete with no open circuit. It is done with the circuit isolated and the CCR disconnected, using a suitable meter. If continuity is lost, the circuit can be split into sections to find where the break is. Continuity alone does not show that insulation is healthy, so it should be followed by insulation testing. See Continuity & Insulation Resistance Testing above.
Airfield lighting insulation resistance test
An airfield lighting insulation resistance test measures how well the cable and connected equipment resist leakage to earth. It is one of the most important checks for finding moisture and insulation damage before they cause faults. Record the result, with conditions such as temperature and weather, so it can be trended over time.
Airfield lighting low insulation resistance
Low insulation resistance in an airfield lighting circuit usually points to water ingress, damaged cable insulation, a poor connector or a failing isolation transformer. Locate the fault by isolating the circuit into sections and testing each, then repair, dry out where needed and re-test. Persistent low readings should be treated as a defect, not a trend to monitor.
Testing a complete series loop with the CCR isolated.
AGL Visual Encyclopedia: Series-circuit testing Circuit continuity Insulation-resistance testing
AGL FAT Testing & Testing Procedures
Testing at the factory and how a testing procedure is written for airfield, airport and ground lighting work.
AGL FAT testing
AGL FAT testing is factory acceptance testing, done at the manufacturer's works before equipment is shipped. It normally covers CCRs, fixtures, transformers and control equipment, and checks electrical, mechanical and, where relevant, photometric performance against the order specification. It is often witnessed by the client or their representative, and passing it is a condition for shipment.
Airfield ground lighting testing procedure
An airfield ground lighting testing procedure sets out what is tested, in what order, with which instruments, and what counts as pass or fail. It normally runs from visual and mechanical inspection through electrical testing to functional and optical checks, with each result recorded. See the AGL Testing Hierarchy section above.
Airfield lighting testing procedure
An airfield lighting testing procedure is the same idea from the aerodrome operator's view: a written, approved method that anyone qualified can follow and get the same result. It should include safety precautions, isolation steps, test equipment and records. Intervals and limits come from your maintenance plan and standards.
Airport lighting testing procedure
An airport lighting testing procedure covers all airside lighting systems, including runway, taxiway, approach, PAPI and signs. A common procedure format keeps results comparable across systems, and each system's specific tests are added as appendices or sub-procedures. Please confirm test criteria with the standard your aerodrome follows.
Testing in six stages, with a failed-test loop.
AGL Visual Encyclopedia: Testing requirement flow Test documentation Pre-commissioning
AGL Inspection Checklist Structure
A good field checklist should contain six phases. Tick items off as you work through a project — this resets on reload.
Identification
Physical
Electrical
Optical
Operational
Documentation
AGL Acceptance Testing
Acceptance testing establishes whether the installed system meets the approved requirements. It should normally verify: Equipment → Installation → Electrical → Mechanical → Functional → Optical → Documentation.
Acceptance criteria should come from approved project specifications, applicable standards, manufacturer requirements, approved drawings and airport requirements.
| Installation Inspection | Acceptance Testing |
|---|---|
| Checks workmanship | Checks final performance |
| During installation | Near completion |
| Physical condition | Measured results |
| Position | Electrical performance |
| Mounting | Functional performance |
| Connections | Optical performance |
| Materials | Final compliance |
Five steps to a system-accepted decision.
AGL Visual Encyclopedia: Final acceptance Commissioning sequence Commissioning
AGL Quality Control Workflow
AGL Testing Matrix
The exact scope depends on the equipment and project requirements.
| Stage | Inspection | Electrical | Functional | Optical |
|---|---|---|---|---|
| Material Receipt | ✓ | As required | — | — |
| Installation | ✓ | As required | — | — |
| Pre-Energization | ✓ | ✓ | — | — |
| Commissioning | ✓ | ✓ | ✓ | ✓ |
| Periodic Maintenance | ✓ | ✓ | ✓ | As required |
| After Repair | ✓ | ✓ | ✓ | As required |
| Final Acceptance | ✓ | ✓ | ✓ | ✓ |
Common AGL Testing Mistakes
1. Testing only when something fails
Testing should also be preventive.
2. Checking only voltage
Correct voltage does not prove complete system health.
3. Ignoring insulation
A circuit can operate today and still have deteriorating insulation.
4. Skipping photometry
Electrical health does not guarantee optical compliance.
5. Using unverified instruments
Poor measurement equipment can produce unreliable conclusions.
6. Not recording results
Unrecorded testing provides little historical value.
7. Not re-testing after repair
Repair completion does not automatically prove system compliance.
8. Comparing against arbitrary values
Use the applicable technical requirement.
9. Testing components without checking the system
AGL is an integrated system.
10. Declaring PASS because the light is ON
ON does not equal compliant.
The AGL Testing Philosophy
Every AGL test should answer three questions:
What are we measuring?
Electrical / Mechanical / Optical / Operational parameter.
What should it be?
Applicable acceptance criterion.
What did we actually measure?
Recorded result.
Measurement + Requirement + Result = Engineering Verification. A reliable AGL testing program does not ask only "is the light working?" — it asks whether the complete AGL system is physically correct, electrically healthy, mechanically secure, optically compliant and operationally reliable. That is the difference between basic inspection and engineering verification.
Standards & References
AGL testing and inspection should always be based on the current applicable edition of the relevant requirements. Exact test values, tolerances and frequencies should not be assumed universally.
Annex 14 and applicable ICAO aerodrome guidance.
AC 150/5340 series, equipment specifications & maintenance guidance.
Applicable IEC standards and Indian Standards; DGCA requirements.
Airport-specific specifications, manufacturer procedures & approved ITP/drawings.
Quick Knowledge Check
Q1. Which statement best captures the AGL testing philosophy?
Q2. A circuit is electrically healthy but a fixture is misaligned. Which test is most likely to catch this?
Q3. What is the correct sequence after a defect is identified?
AGL Testing & Inspection Knowledge Hub
AGL Electrical Testing
Cable, transformer, CCR and circuit testing.
AGL Insulation Resistance Testing
Understanding insulation testing and interpretation.
AGL Cable Testing
Continuity, insulation and fault investigation.
AGL CCR Testing
Output current, steps, control and monitoring.
AGL Transformer Testing
Isolation transformer inspection and verification.
AGL Connector Inspection
Primary and secondary connector quality checks.
AGL Fixture Inspection
Elevated and inset fixture inspection.
AGL Alignment Verification
Checking fixture and PAPI alignment.
AGL Acceptance Testing
Final verification before handover.
AGL Inspection Checklists
Structured field inspection forms.
AGL Troubleshooting Engine
Diagnosis after abnormal test results.
Final AGL Testing Model
Find visible and physical defects.
Measure electrical and system parameters.
Verify optical performance.
Evaluate against the applicable requirement.
Correct the identified defect.
Confirm corrective action.
Create traceable engineering evidence.
Confirm final system performance.
Inspect the installation. Test the circuit. Measure the light. Verify the system. Document the result.
Inspect → Test → Measure → Compare → Rectify → Re-Test → Record
Inspect. Test. Verify.
AGL Testing & Inspection turns visible and measured evidence into engineering verification. Explore the principles, test methods, checklists and standards.
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
Frequently Asked Questions
Q1What is AGL testing and inspection?
AGL inspection is the systematic examination of equipment, installation, components and physical conditions. AGL testing is the measurement or functional verification of defined electrical, mechanical, optical or operational parameters. Together they confirm the system is installed correctly, electrically healthy, mechanically sound and capable of providing the required visual performance.
Q2What are the four dimensions of AGL verification?
Electrical, mechanical, optical and operational. Electrical asks whether the electrical system is healthy, mechanical whether the installation is secure and correctly positioned, optical whether the light produces the required visual performance, and operational whether the complete system operates and responds correctly.
Q3What is the recommended AGL testing sequence?
A useful hierarchy runs from visual inspection and mechanical inspection through electrical testing, functional testing, alignment verification, photometry, system testing and final inspection, and ends with documentation. The sequence helps prevent unnecessary energization of defective equipment.
Q4When should AGL testing be performed?
Exact frequency should follow the applicable airport maintenance program, standards and project requirements. Testing may be required at material receipt, installation, pre-energization, commissioning, acceptance and periodic maintenance, and after equipment replacement, cable repair, major construction, severe weather, suspected lightning damage or abnormal operational performance.
Q5Why inspect equipment before installation?
Testing starts before installation. Incoming fixtures, transformers, CCRs, connectors, cables, PAPI units, signs and control equipment should be checked for correct model, rating, quantity, accessories, physical damage, manufacturing defects, identification, certification, packaging and storage condition.
Q6What does a visual inspection check?
Visual inspection is the first line of AGL quality control and should be documented rather than treated as an informal walk-through. It looks for broken housings, cracks, corrosion, loose hardware, missing covers, damaged lenses, dirty optics, water ingress, cable and connector damage, incorrect installation, missing identification and physical obstruction.
Q7What electrical tests are used in AGL verification?
Electrical testing can include continuity, insulation resistance, voltage, current, circuit resistance, transformer verification, earth continuity, earth resistance where applicable, CCR output and control circuit testing. The exact method and acceptance value must come from the applicable equipment standard, manufacturer instructions and project specification.
Q8What is the difference between a continuity test and an insulation resistance test?
A continuity test verifies that the intended electrical path is complete, for example CCR to cable to transformer to connector to fixture and back. An insulation resistance test can identify moisture, damaged insulation, cable deterioration, ground leakage, incorrect termination and connector problems, and should be performed using the specified test voltage.
Q9Why can an AGL system look normal while having an underlying defect?
AGL systems face moisture, water ingress, temperature variation, lightning, cable deterioration, mechanical impact, vehicle movement, aircraft blast, vibration, corrosion, connector deterioration, optical contamination and equipment ageing. Testing helps identify problems before they become operational failures.
Q10What should be recorded during AGL testing?
Every inspection and test should be recorded so system condition and performance can be demonstrated, trended and defended. For a continuity test, record the circuit number, test points, test instrument, measured result, acceptance criterion and pass or fail.
Q11How to measure insulation resistance in AGL?
Isolate and de-energise the circuit under your site's permit-to-work, lock it out and disconnect the CCR and any equipment the procedure says to disconnect. Use a calibrated insulation resistance tester at the test voltage set by your specification and the cable rating. Connect between the conductor and earth, apply the voltage for the specified time, then read and record the value with the date, circuit and conditions. Discharge the circuit afterwards. Compare the result with the acceptance limit and with earlier readings, and treat a low or falling reading as a defect to investigate.
Engineering & Expert Notes
Visual Inspection Still Finds Many Defects
VisualDamaged seals, loose fixings and contamination are often visible. Allow time for careful observation before instruments come out.
Insulation Tests Need Proper Preparation
ElectricalIsolate and discharge circuits, choose the correct test voltage for the equipment, and record temperature and conditions.
Compare Readings With History
TrendingA passing number can hide a downward trend. Compare against previous results as well as the acceptance limit.
Verify Optical Performance Where Required
PhotometryElectrical acceptance does not prove light quality. Include photometric and alignment checks in the scope.
Define Pass and Fail Criteria Before Testing
CriteriaAgree acceptance values and responsibilities in advance so results are interpreted consistently.
File Reports Where the Next Team Can Find Them
RecordsTest reports are most valuable years later during fault finding. Store them with clear identifiers and revision control.
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Please read before relying on any content on this page or on any record downloaded from it.
- Purpose and intended users. This page is an independent educational and informational reference for competent, suitably trained and authorised airfield ground lighting (AGL) and aerodrome personnel. It is not professional engineering, legal or regulatory advice, and using it creates no professional or client relationship. Learning-path and Academy references describe stages of learning only and are not a certification, accreditation or authorisation.
- Safety. Work on series circuits, constant current regulators (CCRs), isolating transformers, cables, connectors and lighting fixtures can be fatal. Always apply the aerodrome’s permit-to-work and isolation/LOTO procedures, prove dead, use correctly rated instruments and PPE, and follow the manufacturer’s instructions. Nothing here authorises work on live equipment or the bypassing of any safety device or interlock.
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