Airfield Lighting Testing & Commissioning Guide
How to prove an installed AGL system is correctly installed, electrically safe, functionally operational and optically compliant: cable and insulation tests, CCR, transformers, circuits, photometry, PAPI, signs, controls, punch lists and handover records. Commissioning is more than checking that the lights turn on.
What Testing and Commissioning Mean
Airfield lighting testing and commissioning verifies that an installed AGL system is correctly installed, electrically safe, functionally operational and able to provide the intended visual guidance performance. It is not a final check that the lights turn on: it covers the chain from the power supply and CCR through the primary series circuit, isolation transformers and connectors to the fixtures, visual aids, signs and control system.
Testing produces evidence; commissioning uses that evidence to show the system is complete, functional and ready for operation.
Testing vs Commissioning, and Why the Whole System Matters
Testing can include
Commissioning also includes
Path: CCR, primary series cable, isolation transformer, secondary connector, light fixture. Control runs control system, CCR, series circuit, fixtures. PAPI, signs, approach lighting and stop bars have their own power and control.
A defect anywhere affects the result:
- A cable can have continuity but poor insulation
- A transformer can be installed correctly but be defective
- A light can operate with poor photometric output
- A CCR can produce current but not change step correctly
- A PAPI can illuminate but be aimed wrongly
- A sign can be lit but have a control or optical fault
| Activity | Purpose |
|---|---|
| Installation inspection | Verify physical installation |
| Cable testing | Verify electrical circuit integrity |
| Equipment testing | Verify individual component operation |
| Circuit testing | Verify complete electrical circuit |
| Functional testing | Verify operational behaviour |
| Photometric testing | Verify optical performance |
| Integrated testing | Verify system interaction |
| Final inspection | Verify completion |
| Documentation | Create formal commissioning evidence |
| Handover | Transfer the completed system to operations and maintenance |
Installation Inspection, As-Built Verification and Checklist
Light fixtures
Type, location, orientation, elevation.
- Mounting, lens condition, drainage
- Cable entry and connector installation
Housings and junction boxes
Location, access and sealing.
- Secure installation, drainage, cable routing
- Enclosure condition, connector arrangement
- Identification
Primary cables and CCRs
Routing, joints and terminations.
- Identification, mechanical protection, separation
- CCR location, enclosure, ventilation, grounding, labels, control connections
Test against the installed configuration, not only the design drawing. Review single-line diagrams, circuit drawings, layouts, cable, transformer, fixture and CCR schedules, control drawings, PAPI drawings, sign schedules and data sheets. Record every field change for the as-built set, especially a changed cable route, circuit division, transformer location or fixture position.
Before energization, verify
Installation
Readiness
Cable, Insulation, Continuity and Circuit Impedance
Cable testing
Potential tests depend on cable type, circuit arrangement, voltage, specification and electrical requirements: insulation resistance, continuity, conductor identification, cable integrity, fault location, sheath checks and circuit resistance or impedance. Test before final commissioning where practical so construction defects are fixed before energization.
Insulation resistance
Helps find damaged cable, moisture ingress, defective joints, transformer insulation problems, damaged connectors and termination defects. Test voltage, connections, duration and acceptance criteria come from the approved test procedure.
Do not use a generic insulation-resistance number as a universal AGL acceptance limit.
Continuity is not insulation integrity
Continuity finds open circuits, wrong connections, poor joints, wrong terminations and damaged conductors. A cable can show continuity PASS while insulation FAIL, so both tests are needed where specified.
Circuit resistance / impedance
Depends on cable length, conductors, number and type of transformers, fixture load, temperature, configuration and connections. Compare it with design calculations, manufacturer information, approved criteria, factory or site data and the commissioning baseline. A significant difference should be investigated.
| Insulation test record field | Impedance verification record field |
|---|---|
| Circuit number, cable identification | Circuit identification |
| Instrument and serial number | Cable length and configuration |
| Calibration status | Number and type of connected transformers |
| Test voltage and duration | Measurement conditions and test equipment |
| Temperature or conditions | Measured value and design/reference value |
| Measured resistance, acceptance criterion, result | Difference and assessment |
Related Guides
Series-Circuit Impedance Calculator Series-Circuit vs CCR Testing Cables & Connector EngineeringTransformers, Connectors and CCR Testing
Isolation transformer
Follow the manufacturer instructions and project specification.
- Physical and nameplate inspection
- Primary and secondary checks
- Insulation, winding continuity, polarity where applicable
- Damage and moisture ingress
Nameplate verification
Must match the approved equipment schedule.
- Manufacturer, model, rating, serial number
- Primary and secondary characteristics
- Project identification and circuit association
- A wrong rating causes downstream lighting problems
Connectors
Inspect every connector before energization.
- Correct type, assembly and termination
- Secure, no damage, moisture or corrosion
- Correct identification
- Defects cause high resistance, intermittent faults or open circuits
CCR commissioning
Consider incoming supply, output current, intensity steps, current regulation, control response, local and remote control, monitoring, alarms, fault indications, protective functions, interlocks, communication and standby functions where applicable. Follow the manufacturer's commissioning procedure for internal adjustments and protective functions. The FAA specification for CCRs and regulator monitors is AC 150/5345-10H.
Current-step testing
Verify each step: the command is received, the CCR moves to the correct condition, output is stable, monitoring reports the state and the lighting responds. Take current values and tolerances from the CCR specification, not a generic table.
Local control
Test ON/OFF, step selection, status and alarm indication, reset and protective trips where specified. Confirm both command and response.
Remote control
Test from the airport's actual control system: ON/OFF, intensity, acknowledgement, feedback, faults, loss of communication, local/remote selection and interlocks.
Functional and Brightness-Step Testing
Complete-circuit functional test
Show that the whole circuit operates together, not only that each fixture works. The chain should be:
Command
CCR response
Correct current / intensity
All connected fixtures respond
Correct visual pattern
Monitoring confirms status; no unexpected alarms
Brightness-step testing
For each commanded step record: commanded condition, CCR response, circuit current, fixture response, control-system indication, abnormal behaviour and alarms. It can reveal:
- Incorrect CCR programming or missing intensity levels
- Unstable current or incorrect control signals
- Communication problems and monitoring errors
- Failed or uneven fixtures
- Wrong local/remote configuration
Treat it as an integrated commissioning test, not simply a CCR test.
Photometric Verification
Photometry verifies the optical result: intensity, beam distribution, colour, coverage, orientation, alignment and fixture-to-fixture consistency. It may be required for runway edge, threshold and end, centreline, touchdown zone, approach, taxiway edge and centreline lighting, stop bars, runway guard lights and PAPI. The method must match the lighting function and the acceptance criteria. The FAA specification for runway, taxiway, heliport and vertiport light fixtures is AC 150/5345-46F.
Typical sequence
Verify test equipment calibration
Confirm fixture identification
Confirm operating intensity
Establish measurement geometry
Measure required optical parameters
Compare results with approved criteria
Identify failed or degraded units
Perform corrective action
Repeat the measurement
Issue the final photometric report
Keep the link between each measurement, fixture location and acceptance criterion.
Electrical to optical: electrical input, CCR, series circuit, transformer, light fixture, optical system, measured light output. Electrical commissioning shows the system supplies the expected operating condition; photometry verifies the final optical result.
PAPI Testing
PAPI needs specialized commissioning because its function depends on optical geometry as well as electrical operation. The FAA specification for PAPI systems is AC 150/5345-28H.
Functional
Operation first.
- All units operate, brightness appropriate
- Control commands received
- Indications correct and stable, no flicker
Alignment
An engineering measurement.
- Reference and unit elevation, horizontal position
- Spacing, azimuth, vertical aiming, runway relationship
- Do not confirm by judging red/white from the ground
Photometric
Retain data and calibration records.
- Intensity, beam coverage, colour
- Alignment-related parameters and transition characteristics where applicable
- Consistency among units
Related Guides
PAPI Engineering Guide PAPI Alignment, Testing & Maintenance Field Guide ICAO PAPI Requirements PAPI/APAPI Testing & CommissioningSign, Control-System and SCADA Testing
Signs
FAA AC 150/5340-18H covers siting, design and installation of airport signs and AC 150/5345-44L covers the specification for runway and taxiway signs; both are listed as active.
- Installation, location, orientation, legend, identification
- Mechanical condition, electrical connections
- Illumination, brightness and control, monitoring, circuit association
- Emergency/backup behaviour where applicable
- Functional test: command, sign energized, correct legend, status feedback; verify each independently controlled sign against its control point
Control system
- Local and remote controls, intensity commands, circuit selection
- Status feedback, equipment alarms, CCR monitoring
- Communication links, interlocks, emergency controls
- Fail-safe behaviour where specified
SCADA / monitoring
Verify equipment, circuit and CCR status, current or intensity information, alarms, communication-loss and fault indication, command acknowledgement, event logging and time/date. Test both directions: control to field, and field to monitoring.
Integrated Commissioning and the End-to-End Sequence
The strongest test follows the operational chain: the operator selects an intensity, the control system sends the command, the CCR changes step, the primary circuit responds, fixtures illuminate, photometric output matches the required condition and the monitoring system reports the correct status.
Test progressively: component, then circuit, then system, then integrated operation. Do not energize and troubleshoot the entire airfield system at once.
Design and document review
Pre-commissioning inspection
Cable continuity testing
Insulation resistance testing
Transformer and connector inspection
Circuit resistance / impedance verification
CCR testing
Initial energization
Functional testing
Brightness-step testing
Photometric testing
PAPI testing
Sign testing
Control and monitoring testing
Integrated system testing
Final inspection
Punch-list closure
Retesting
As-built and documentation review
Final commissioning approval and handover
Retest Selector: What to Repeat After Corrective Work
Pick a repair to see which tests should be repeated.
Punch Lists, FAT / SAT, Hold Points and Safety
Punch list
Typical items: wrong fixture orientation, damaged connector, missing label, cable identification, incomplete sealing, incorrect transformer, failed insulation test, low photometric result, PAPI alignment, sign-control mismatch, CCR alarm, SCADA point.
- Unique reference and location
- Description and responsible party
- Corrective action and status
- Retest requirement and closure date
Factory vs site acceptance
FAT is done before shipment: construction, functionality, electrical performance, control interfaces, alarms, factory configuration and documents. SAT is done after installation: site wiring, power, field interfaces, the actual control system, communications and field performance. For CCRs, control panels and monitoring systems, FAT and SAT complement site commissioning; they do not replace it.
| Point | Example |
|---|---|
| Hold point | Cable testing complete, approval before circuit energization |
| Witness point | CCR commissioning, consultant or authority witness |
| Hold point | Photometric acceptance, approval before operational handover |
| Document review | Final commissioning dossier, approval before closeout |
Commissioning safety
Common AGL Commissioning Failures
Click a failure to see the possible causes.
Cable insulation failure
Possible causes
- Cable damage, moisture
- Poor joint, incorrect termination
- Construction damage
Open circuit
Possible causes
- Broken conductor, incorrect connection
- Failed connector, loose termination
Abnormal circuit impedance
Possible causes
- Incorrect cable, unexpected circuit length
- Incorrect transformer, poor connection
- Incorrect circuit configuration
CCR does not reach required step
Possible causes
- Configuration problem
- Control-system issue
- CCR fault, monitoring issue
One light does not operate
Possible causes
- Transformer, connector
- Fixture, secondary wiring
Multiple lights do not operate
Possible causes
- Primary cable, CCR
- Control system, circuit fault
Photometric failure
Possible causes
- Contamination, wrong fixture, incorrect optics
- Alignment, degraded light source
- Electrical operating condition
PAPI failure
Possible causes
- Incorrect aiming, elevation error
- Optical problem, failed light source
- Control problem, mechanical disturbance
Sign does not respond correctly
Possible causes
- Wiring, address/configuration, controller
- Incorrect circuit, lamp/LED assembly
- Monitoring/control problem
Test Records, Baseline, Dossier and Report
| Field | Example |
|---|---|
| Airport / Runway-Taxiway / Circuit | Project airport, RWY/TWY ID, circuit ID |
| Equipment and equipment ID | CCR / transformer / light, asset ID |
| Test type | Insulation / current / photometry |
| Instrument, serial number, calibration | Make and model, instrument ID, certificate reference |
| Test condition | Specified operating state |
| Measured result and acceptance criterion | Recorded value, controlled requirement |
| Status and corrective action | Pass / fail, description |
| Retest result, technician, date | Pass / fail, name or ID, test date |
Commissioning baseline
Reference for all future maintenance.
- CCR output, circuit characteristics, transformer data
- Fixture identification, photometric performance
- PAPI alignment, sign operation, control configuration
Commissioning dossier
What the handover package normally holds.
- Project data and commissioning date, approved, red-line and as-built drawings
- Equipment records, certificates, calibration certificates, spare-parts lists
- All test records, punch list, retests, final inspection
- Commissioning certificate, O&M manuals, training, handover
Commissioning report
Should answer seven questions.
- Installed correctly? Electrically safe and functional?
- Lighting operated correctly? Optical system performed?
- PAPI and signs correct? Control system correct?
- All defects closed?
Acceptance rests on objective evidence: installation, electrical, functional, optical, control/monitoring evidence, final inspection and complete documentation. Record actual measurements, not PASS/FAIL only, wherever a quantitative result exists. Keep every result traceable: airport, runway/taxiway, circuit, equipment, test, result.
Related Guides
AGL Maintenance & Preventive Maintenance Forms: Photometry & Optical Testing Photometry Testing SOPRehabilitation, LED Conversion and Common Mistakes
Testing during rehabilitation
Commissioning is also required after runway or taxiway lighting replacement, CCR, cable or transformer replacement, control upgrade, LED conversion, PAPI or sign replacement and pavement reconstruction. The scope should reflect the work done: a small replacement does not need the programme of a full reconstruction, but the affected interfaces must be verified.
LED commissioning
Check fixture, LED module, optics, intensity settings, colour, and compatibility with controls, CCR, transformer and monitoring, plus photometric performance. Do not accept an LED fixture just because it saves power or lights up.
Common mistakes
- Testing only whether lights turn on
- Skipping insulation testing
- Using uncalibrated test equipment
- Not recording the operating intensity
- Treating all lights as identical
- Ignoring control-system feedback
- Closing defects without retesting
- Not preserving baseline data
Standards and Reference Framework
Annex 14 Vol. I with applicable aerodrome design and maintenance guidance.
AC 150/5340-30J, 26C, 5345-10H, 5345-46F, 5340-18H, 5345-28H.
Approved design, contract specification and controlled equipment documentation.
Manufacturer instructions and equipment ratings.
| FAA reference | Subject |
|---|---|
| AC 150/5340-30J | Design and Installation Details for Airport Visual Aids |
| AC 150/5340-26C | Maintenance of Airport Visual Aid Facilities |
| AC 150/5345-10H | Constant Current Regulators and Regulator Monitors |
| AC 150/5345-46F | Runway, Taxiway, Heliport and Vertiport Light Fixtures |
| AC 150/5340-18H | Standards for Airport Sign Systems |
| AC 150/5345-44L | Runway and Taxiway Signs |
| AC 150/5345-28H | Precision Approach Path Indicator (PAPI) Systems |
These FAA documents appear on the FAA's list of advisory circulars required for use in AIP-funded projects (checklist dated 5 March 2025). AC 150/5340-18H and AC 150/5345-44L are shown as active on their FAA records, both issued 30 September 2024. The ICAO Store lists Annex 14 Volume I as the 9th Edition (July 2022), with Amendment 18 dated 4 August 2025 and corrigenda issued in 2023 and 2026, including Corrigendum No. 3 dated 8 June 2026. Check the ICAO Store for the current edition, amendments and corrigenda before relying on a specific edition.
References
- FAA: Advisory Circulars required for use in AIP (5 March 2025)
- FAA record: AC 150/5340-18H
- FAA record: AC 150/5345-44L
Related Guides
ICAO Annex 14 AGL Requirements FAA AC 150/5340 Series Explained AGL Testing & InspectionAGL Testing Checklist and Handover Checklist
Pre-commissioning
Electrical
Functional
Optical
Final
Handover: records
Handover: closeout
Prove the system, then keep the baseline
Quantitative, traceable and repeatable commissioning records serve project acceptance and become the baseline for maintenance, troubleshooting and performance monitoring.
Quick Knowledge Check
Q1. A cable shows continuity PASS. What does that tell you about insulation?
Q2. Why should a generic insulation-resistance value not be used as a universal limit?
Q3. Brightness-step testing is best described as:
Q4. After replacing a fixture, what should be done?
Q5. Why is the commissioning baseline valuable?
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Open AGL Photometric Testing Guide →Runway Lighting Photometry
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Edge, centreline, stop bar and guard lights.
Open Taxiway Lighting Photometry →Airport Isolating Transformer
Types, ratings and failure modes.
Open Airport Isolating Transformer →Junction Boxes & Light Bases
Housings, bases and installation.
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Wider testing and commissioning reference.
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AGL Testing & Commissioning FAQ
Q1What is airfield lighting commissioning?
Airfield lighting commissioning is the formal process of verifying that an installed AGL system has been correctly installed, electrically sound, operationally functional and capable of meeting its applicable performance requirements.
Q2What tests are required for AGL commissioning?
Typical tests include cable continuity, insulation resistance, transformer checks, connector inspection, CCR testing, circuit measurements, functional testing, brightness-step testing and photometric verification. PAPI, signs and control systems require additional dedicated tests.
Q3What is an AGL testing checklist?
An AGL testing checklist is a structured list used to verify that the electrical, optical, mechanical, functional and control aspects of an airport lighting installation have been tested and documented.
Q4Why is insulation resistance testing required?
It helps identify damaged or degraded insulation, moisture, defective joints and other conditions that can compromise circuit integrity.
Q5Is continuity testing enough?
No. Continuity demonstrates that an intended electrical path exists; it does not by itself demonstrate acceptable insulation condition.
Q6How is a CCR tested during commissioning?
CCR testing can include input power, output current, intensity steps, current regulation, alarms, controls, monitoring, local/remote operation and protective functions, according to the applicable specification and manufacturer procedure.
Q7What is circuit impedance testing?
It is the measurement of the electrical characteristics of the installed circuit and can be compared with design calculations or commissioning baselines to identify abnormal circuit conditions.
Q8Is photometry part of commissioning?
Where required by the project or applicable standard, yes. Photometry verifies the optical performance of the installed lights rather than only their electrical operation.
Q9How is PAPI commissioned?
PAPI commissioning includes functional operation plus verification of position, elevation, alignment, aiming and optical performance as applicable.
Q10Are airport signs included in AGL commissioning?
Where the project includes lighted/sign systems, sign installation, electrical function, control and monitoring should be commissioned as applicable.
Q11What documents are required at handover?
The final package commonly includes test certificates, calibration records, photometric results, equipment records, as-built drawings, PAPI/sign/control-system test records, punch-list closure records, O&M manuals and commissioning certificates.
Q12What happens when an AGL test fails?
The failed result should be investigated, the cause identified, corrective action completed and the affected test repeated. The final record should contain both the original failure and the successful retest.
Engineering & Expert Notes
Know What Is Testing and What Is Commissioning
ScopeTesting checks individual items and circuits; commissioning proves the integrated system works as intended. Plan both.
Complete Cable and Insulation Tests Before Energisation
ElectricalEarly detection of faults prevents damage and delay. Repeat tests if work disturbs cables afterwards.
Test All Brightness Steps
FunctionalCheck operation at each intensity step and during changes between steps, not only at full brightness.
Include Photometry and Alignment
OpticalDocument the optical performance of key lights and verify PAPI and other aimed units.
Define Retest Rules
RetestsAgree what must be repeated after a repair or change. This avoids arguments and keeps records consistent.
Leave a Baseline for the Operator
BaselineProvide test records, settings and photos so the operator can compare future measurements with commissioning data.
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