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Safety-critical technical reference — read before use. Independent educational guidance for qualified AGL and aerodrome personnel. It is not an approved procedure, design, specification or regulatory instruction and does not replace your aerodrome’s permit-to-work, isolation/LOTO procedures, the approved design or the manufacturer’s instructions. Series-circuit AGL equipment can carry lethal voltages. Read the full disclaimer ↓
PRECISION AGL ACADEMY · Operational Safety Communication

NOTAMs (Notice to Airmen)

An AGL engineering and operational guide to aerodrome notices. A NOTAM is an aeronautical notice issued through the appropriate aviation information system to communicate the establishment, condition, change or removal of an aeronautical facility, service, procedure or hazard — when that information is timely and operationally significant. For Airfield Ground Lighting, a NOTAM is not simply an engineering maintenance record. It is an operational safety communication.

Detect Assess Report Publish Maintain Cancel
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Overview

1. What Is a NOTAM?

NOTAM stands for Notice to Airmen. Its purpose is to provide timely operational information to aviation users about conditions that may affect flight operations. The exact circumstances requiring a NOTAM are determined by applicable aeronautical information regulations and the responsible aerodrome/aviation authority — not by an individual engineer's judgement alone.

Examples of what a NOTAM can cover:

Runway availability Taxiway availability Aerodrome lighting Approach lighting PAPI Runway edge lighting Runway centreline lighting Taxiway lighting Airfield signs Navigation facilities Aerodrome operational restrictions Temporary hazards Construction or maintenance activities

A serviceability level only means something if it is measured the same way every time and reported to the people who need it. Each light is checked against the 50 per cent line, the lights are counted by type, the result is compared with the objective and the adjacency rule, and the outcome is logged and passed on.

MEASURE AND REPORT FROM LIGHT CHECKED TO LEVEL REPORTED 1 INSPECT lit? clean? aimed? 2 MEASURE intensity vs 50% line 3 COUNT per type, per circuit 4 COMPARE % and adjacency 5 REPORT log, notify, NOTAM WORKED EXAMPLE: RUNWAY EDGE, CAT II/III Lights installed 60 Unserviceable 3 Serviceable 57 57 ÷ 60 95% Objective 95% MET Adjacent pairs NONE HOW EACH LIGHT IS CHECKED VISUAL PATROL lit or not, dirty, obscured, damaged MOBILE MEASURING UNIT intensity, beam spread, orientation vs 50% line MONITORING SYSTEM, WHERE FITTED lamp and circuit status to the control room CAT II/III in-pavement lights: intensity checks at least twice a year WHAT A GOOD LOG RECORDS Light type and circuit Installed and out Positions of outages Time found and restored SCHEMATIC · EXAMPLE FIGURES ARE ILLUSTRATIVE · NOT TO SCALE
Figure 1. A serviceability level only means something if it is measured the same way every time and reported to the people who need it. Each light is checked against the 50 per cent line, the lights are counted by type, the result is compared with the objective and the adjacency rule, and the outcome is logged and passed on.
AGL Visual Encyclopedia: Serviceability measured and reported
2. Why It Matters

Why NOTAMs Matter in AGL

An AGL defect can be more than a maintenance problem — it can change what visual guidance an aircraft actually receives. The engineering team identifies and communicates the technical condition through the airport's established reporting process; the authorized aeronautical information function determines and issues the operational notice.

Runway Lighting Failure
Reduced Visual Guidance
Operational Impact
Assessed by Airport Authority
Appropriate Operational Action
NOTAM If Required

The red lights and cross markings that say part of a runway or taxiway cannot be used, and why the normal lights are switched off inside it.

PLAN VIEW · A CLOSED PORTION IN THE MIDDLE OF A RUNWAY AND OF A TAXIWAY A · CLOSED PORTION OF A RUNWAY UNSERVICEABILITY LIGHTS · RED CLOSED MARKING · WHITE CROSS OPEN CLOSED · LIGHTS NOT OPERATED OPEN B · CLOSED PORTION OF A TAXIWAY UNSERVICEABILITY LIGHTS · RED CLOSED MARKING · YELLOW CROSS OPEN CLOSED · LIGHTS NOT OPERATED OPEN WHAT A PILOT SEES RED ACROSS THE WAY IN DO NOT ENTER THE CLOSED AREA A CROSS ON THE SURFACE WHITE ON A RUNWAY, YELLOW ON A TAXIWAY NORMAL LIGHTS ARE OFF NO GUIDANCE LEADS INTO THE CLOSED AREA RED ACROSS THE ENTRANCE · CROSS ON THE SURFACE · NORMAL LIGHTS OFF INSIDE
Figure 2. The red lights and cross markings that say part of a runway or taxiway cannot be used, and why the normal lights are switched off inside it.
AGL Visual Encyclopedia: Closed runway marking lights Closed taxiway and unserviceability lighting
3. A Critical Distinction

NOTAM vs Maintenance Report

These are different documents. A maintenance engineer should not treat a maintenance report as automatically equivalent to a NOTAM — the two serve different audiences and different purposes, even when they originate from the same fault.

Maintenance ReportNOTAM
Technical recordOperational information
Used by engineering/maintenanceUsed by aviation operational users
Records inspection/failureCommunicates operationally significant information
Contains technical detailsUses standardized aeronautical information
Internal/project recordPublished through authorized aeronautical information channels

Turn each maintenance requirement into a planned task with an interval and an acceptable condition, then isolate, work, verify, restore and record.

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 3. Turn each maintenance requirement into a planned task with an interval and an acceptable condition, then isolate, work, verify, restore and record.
AGL Visual Encyclopedia: How do requirements flow into AGL maintenance
4. Potential Triggers

When Can AGL Problems Become NOTAM-Relevant?

Whether a particular condition requires a NOTAM depends on its operational significance and the applicable aeronautical information procedures — not on the fact that a fault exists. Potential examples include:

Runway Lighting

  • Unavailable
  • Partially unavailable
  • Edge lights affected
  • Centreline lights affected

Taxiway Lighting

  • Unavailable
  • Stop bars affected
  • Temporary configuration changes

Approach Lighting

  • Unavailable or degraded system
  • Significant lighting restrictions

PAPI

  • Unavailable
  • Under maintenance / restriction

Airfield Signs

  • Unavailable
  • Lighting-related works affecting operations

The Governing Question

Not "is something wrong?" but "does this change published or expected operational conditions, per applicable procedure?"

A count only matters if it sets work in motion. Each result falls into one of three bands: within the objective, at the action level, or not met. Each band has its own response, from routine scheduling to telling airfield control straight away.

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 4. A count only matters if it sets work in motion. Each result falls into one of three bands: within the objective, at the action level, or not met. Each band has its own response, from routine scheduling to telling airfield control straight away.
AGL Visual Encyclopedia: How does a serviceability result trigger maintenance
5. The Engineering Model

The AGL-to-NOTAM Chain

AGL FAULT
DETECTION
TECHNICAL VERIFICATION
OPERATIONAL IMPACT ASSESSMENT
REPORT TO AUTHORIZED AIRPORT FUNCTION
NOTAM DECISION
NOTAM ISSUANCE
MAINTENANCE / RECTIFICATION
VERIFICATION
NOTAM CANCELLATION OR UPDATE

The key principle: engineering identifies and verifies the condition. Authorized operational/aeronautical information personnel determine and issue the appropriate notice.

Make the circuit safe, read the symptom at the CCR, then narrow the fault down section by section until one part remains.

FAULT-ISOLATION FLOWCHART · SYMPTOM, TYPE, SECTIONFIRSTTELL ATC · SWITCH OFF AND ISOLATE THE CCR · LOCK OFF · AUTHORISED PERSONNEL ONLYALL LIGHTS OUTCCR open-circuit alarm, no currentOPEN CIRCUITa break in the loopTEST CONTINUITY BY SECTIONFault is where it failsCCR TRIPSEarth-fault or overcurrent alarmEARTH FAULTinsulation to earth is lowTEST INSULATION RESISTANCE BY SECTIONLow reading marks the sectionSOME LIGHTS OUTCCR normal, circuit runningLOCAL FAULTfixture, connector or transformerCHECK THE DEVICE ITSELFLight, secondary connector, transformerNARROW DOWN BY HALF-SPLITTEST: GOOD · SET ASIDEBAD · SPLIT AGAINfault sectionTHEN1 Repair the faulty part2 Retest section and circuit3 Restore, run, confirm status4 Record results, tell ATC
Figure 5. Make the circuit safe, read the symptom at the CCR, then narrow the fault down section by section until one part remains.
AGL Visual Encyclopedia: A fault isolated in a series circuit
6, 7 & 8 · By System

NOTAM Considerations Across Lighting Systems

Runway Lighting

Contributes to visual guidance during aircraft operations.

  • Complete runway lighting failure
  • Partial runway edge-light failure
  • Centreline lighting outage
  • Threshold / TDZ lighting condition
  • Runway end lighting condition
  • Reduced lighting capability
  • Lighting system under maintenance

Taxiway Lighting

Supports aircraft ground movement.

  • Edge / centreline lighting unavailable
  • Stop bar lighting unavailable
  • Runway guard light condition
  • Lighting system restricted during maintenance
  • Temporary configuration

Approach Lighting

Provides visual information during the transition toward the runway.

  • Centreline lighting
  • Crossbars
  • Sequenced flashing components
  • Other approach-lighting elements

Identify exactly which portion of the system is affected — never simply report "approach lights faulty."

Understand how airport ground lighting systems, visual aids, electrical circuits and control equipment fit together in a typical airport layout.

TERMINALTOWERAPPRWYTWYSTDCCR HOUSELV DISTRIBUTIONAPRON FLOODLIGHTSWINDSOCK (LIT)LOCALISERLANDING DIRECTIONRUNWAYPARALLEL TAXIWAYAPPROACHLIGHTSAPRON123456789SERIES CIRCUITS FROM THE CCR HOUSE (APPROACH, RUNWAY, TAXIWAY, STAND GUIDANCE)LOW-VOLTAGE SUPPLY TO APRON FLOODLIGHTS (NOT A SERIES CIRCUIT)TYPICAL LAYOUT · CONCEPTUAL PLAN VIEW · NOT TO SCALE
Figure 6. Understand how airport ground lighting systems, visual aids, electrical circuits and control equipment fit together in a typical airport layout.
AGL Visual Encyclopedia: What does a complete AGL airport layout look like
9. A Subtle Trap

NOTAM and PAPI: "Light ON" ≠ "Correctly Serviceable"

PAPI is an important visual approach aid. Potential conditions include complete outage, one or more light units unavailable, misalignment, maintenance or an operational restriction. However, a PAPI that is physically illuminated is not necessarily operationally correct.

Light ON does not automatically mean PAPI correctly aligned and serviceable. Technical verification should therefore accompany operational reporting.

Same Illuminated Unit, Two Different Technical States

A powered, visibly lit PAPI can still present a false glide-path indication — the fault is optical, not electrical, so it will not show up as "light off"

CORRECTLY ALIGNED & SERVICEABLE PAPI UNIT PILOT EYE Beam split correctly split on the nominal glide path Indication is trustworthy ILLUMINATED BUT MISALIGNED PAPI UNIT (POWERED) PILOT EYE Beam physically on, but aimed off the nominal glide path Indication is misleading — verify, don't assume
10. Airfield Signs & 11–12. Planned vs Emergency

Signs, Planned Maintenance & Emergency Failure

Illuminated Signs

Operational importance depends on location, sign function and applicable airport procedures.

  • Sign completely unavailable
  • Sign partially illuminated
  • Incorrect sign displayed
  • Sign electrical failure
  • Sign undergoing replacement or temporary removal

Emergency AGL Failure

Speed matters, but accuracy matters equally. Never communicate an unverified technical assumption as an operational fact.

  • Immediate detection → confirm condition
  • Notify airport operations
  • Assess operational impact
  • Initiate applicable aeronautical information procedure
  • Rectify → test → restore → update/cancel

Planned maintenance workflow: Maintenance Plan → Affected AGL Identified → Operational Impact Assessed → Airport Operations / ATC / AIS Coordination → Required Notice or Restriction → Maintenance Work → Testing → Restoration → Notice Cancellation/Update if applicable.

The order of work after a fault — report and assess, locate while live, isolate and prove dead, repair, test, then restore, verify and record the cause, so the fault is fixed and does not come back.

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. The order of work after a fault — report and assess, locate while live, isolate and prove dead, repair, test, then restore, verify and record the cause, so the fault is fixed and does not come back.
AGL Visual Encyclopedia: The corrective maintenance sequence Sign maintenance
13 & 14. Reporting Discipline

Engineering Information Required — and Why Exact Location Is Critical

Avoid vague statements such as "Runway lights not working." When reporting an AGL condition internally for possible aeronautical information action, capture the following.

Airport Date/time Exact location Runway/taxiway identifier Lighting system Affected component Number of affected units Percentage/extent Failure condition Operational status if known Maintenance status Expected restoration time Engineer/technician Test results Supporting records
The exact information required for a NOTAM request depends on the applicable national and airport procedures. Engineering records should identify runway designation, lighting type, affected section and units, direction/location, circuit identification and nature of defect — accurate location information reduces the risk of operational misunderstanding.
15 & 16. Chain of Communication

NOTAM Information Flow & Who Issues a NOTAM

A NOTAM is not normally issued by an AGL technician simply because a lighting fault has been discovered. The issuance process is governed by the applicable State aeronautical information framework and airport procedures; AGL personnel provide accurate technical information to the authorized function.

AGL Technician
AGL Engineer
Maintenance Control
Airport Operations
Aeronautical Information Service
NOTAM System
Aviation Users
The exact organizational structure differs between airports and States.
17, 18 & 19. Don't Confuse These

NOTAM vs Fault Log, SNOWTAM & AIP

Several documents look related but serve distinct purposes — and can originate from the same event without being interchangeable.

DocumentWhat It Communicates
AGL Fault LogEquipment, failure, measurements, diagnosis, repair, technician, test results.
NOTAMOperationally significant condition, affected facility, relevant period, operational status, restoration/update information.
SNOWTAMA specialized aerodrome condition report tied to runway surface conditions from snow, slush, ice, frost or related contamination. AGL failures are normally handled through the NOTAM/aeronautical information process, not treated as SNOWTAM information.
AIPRelatively permanent aeronautical information of lasting operational relevance.

A useful principle: AIP = Published Aeronautical Information. NOTAM = Time-Critical Change / Condition Information. The exact publication mechanism is governed by the applicable State AIS framework.

20, 21 & 22. Restoration Discipline

"Lights ON" Does Not Equal "System Restored"

Restoration is not complete simply because the technician repairs the equipment. A fixture may illuminate while still having incorrect intensity, incorrect colour, poor alignment, intermittent operation, incorrect circuit configuration, damaged optics or other performance problems.

REPAIR
ELECTRICAL TEST
FUNCTIONAL TEST
VISUAL INSPECTION
PHOTOMETRIC VERIFICATION WHERE REQUIRED
OPERATIONAL CONFIRMATION
NOTIFY AUTHORIZED FUNCTION
UPDATE/CANCELLATION OF NOTICE

Photometry becomes important when a defect affects actual optical performance. Fixture electrically operational does not automatically establish required photometric performance achieved. Where applicable, photometric verification supports the technical confirmation of restoration.

The controlled return of a circuit to service once maintenance is done: everything cleared and closed up, tested, the isolation removed in order, the circuit re-energised and checked, and the work recorded. The job is not finished when the last bolt is tight.

POST-MAINTENANCE RESTORATION SAME PIT, SAME LIGHTS, BEFORE AND AFTER RESTORATION NOT READYREADY FOR SERVICE LID AJAR, TOOL LEFT, LOCK ON, LIGHTS DARK CLEAR, CLOSED, TESTED, LIGHTS ON RESTORATION SEQUENCE Complete and clearTools, materials, peopleClose upLids, covers, fixturesTestInsulation, continuityRemove isolationLock-off per procedureEnergise, checkCCR, alarms, lightsRecord, hand backReport to control Do not remove an isolation until everyone on the circuit has confirmed they are clear. SCHEMATIC · RESTORATION STEPS FOLLOW THE SITE PROCEDURE · NOT TO SCALE
Figure 8. The controlled return of a circuit to service once maintenance is done: everything cleared and closed up, tested, the isolation removed in order, the circuit re-energised and checked, and the work recorded. The job is not finished when the last bolt is tight.
AGL Visual Encyclopedia: Post-maintenance restoration
23, 24 & 25. Diagnosing Extent

CCR, Series-Circuit & Individual Light Failures

CCR Failure

Can affect an entire lighting circuit — runway, taxiway, approach or PAPI outage, or reduced intensity capability.

Trace: Which CCR → Which circuit → Which lighting system → What operational effect?

Series-Circuit Failure

A single fault can affect multiple lighting units.

  • Cable fault
  • Earth fault
  • Open circuit
  • Transformer failure
  • Connector failure
  • CCR problem

Individual Light Failure

A single failed fixture does not automatically mean a NOTAM is required. The engineering/operations team must determine:

  • Location
  • Function
  • Number of failed units
  • Remaining serviceable lights
  • Operational significance
  • Applicable reporting criteria

Technical failure ≠ Automatically NOTAM.

Where One Fault Can Sit in the Chain

The same symptom — lights not performing correctly — can originate at three very different levels, each with a different NOTAM implication

CCR entire circuit at risk SERIES CIRCUIT LOOP cable / earth / open-circuit / transformer fault — multiple units affected FIXTURE A isolated failure FIXTURE B isolated failure FIXTURE C isolated failure Same visual symptom, different technical scope — trace the level before deciding operational significance CCR-level and circuit-level faults are more likely to reach NOTAM significance than one isolated fixture
26, 27 & 38. Planned Work

Replacement, Project Work & Commissioning

Before replacing AGL equipment or starting project work, coordinate with airport operations and the authorized aeronautical information function before affecting operational facilities.

Before Planned Replacement, Consider

  • Which system is affected?
  • Is the system operationally required?
  • How long will it be unavailable?
  • Does the work affect runway/taxiway availability?
  • Are temporary measures available?
  • What coordination is required?
  • Is an aeronautical information action required?

Project & Commissioning Changes Can Include

  • Runway lighting modifications
  • Taxiway closure
  • Approach lighting work / PAPI replacement
  • Sign installation, cable works, CCR replacement
  • Lighting system under testing
  • Temporary runway restrictions
  • PAPI installation
  • Approach lighting construction
  • Taxiway lighting modification
  • New signs under commissioning

The fixed order for AGL maintenance: plan and get the permit, brief, isolate and prove dead, work within the permit, test and restore, then hand back and record.

SAFE MAINTENANCE · PLAN, BRIEF, ISOLATE, WORK, RESTORE, CLOSE OUT 1 PLAN Permit & approval 2 BRIEF Team & site ready 3 ISOLATE Lock, tag, prove dead 4 WORK Within the permit 5 RESTORE Test, then energise 6 CLOSE OUT Hand back & record PLAN VIEW · MAINTENANCE ON A SERIES CIRCUIT, FROM THE PERMIT TO THE WORK SITE NEVER OPEN A LIVE SERIES LOOP · ISOLATE AND PROVE DEAD FIRST · A DARK FIXTURE IS NOT A DEAD CIRCUIT PERMIT TO WORK Ops / ATC approval SCOPE · AREA · TIME TOOLBOX BRIEFING PPE · tools · escort · FOD ALL KNOW THE PLAN ISOLATE AT THE CCR Lock · tag · prove dead · earth OWN LOCK, EVERY PERSON 1 2 3 SERIES CIRCUIT LOOP · DEAD ONLY WHILE ISOLATED 4 WORK AREA · TOOLS COUNTED · FOD CONTROLLED 5 RESTORE · TOOLS COUNTED OUT · TESTED · LOCKS REMOVED BY OWNERS · ENERGISE ON AUTHORISED WORD 6 CLOSE OUT · PERMIT HANDED BACK · OPS / ATC TOLD · WORK AND DEFECTS RECORDED SCHEMATIC · STEPS FOLLOW YOUR SITE PROCEDURE, PERMIT TO WORK AND THE MANUFACTURER’S INSTRUCTIONS
Figure 9. The fixed order for AGL maintenance: plan and get the permit, brief, isolate and prove dead, work within the permit, test and restore, then hand back and record.
AGL Visual Encyclopedia: The safe maintenance sequence Electrical isolation
33. Internal Reporting

AGL NOTAM Internal Reporting Form

A practical internal template AGL teams can adapt to capture the information the authorized NOTAM function will need.

Event Information
Airport 
Date 
Time 
Runway/Taxiway 
AGL System 
Equipment 
Circuit 
Condition
Failure/Restriction 
Affected Units 
Affected Section 
Technical Cause 
Operational Information
Operational Impact IdentifiedYES / NO / UNDER ASSESSMENT
Operations NotifiedYES / NO
Authorized NOTAM Function NotifiedYES / NO
Restoration
Repair Completed 
Testing Completed 
Functional VerificationPASS / FAIL
Photometry RequiredYES / NO
Restoration Confirmed 
Remarks 
34. Interactive

NOTAM Communication Checklist for AGL Engineers

When reporting a lighting problem, walk through each of these before you communicate it. This resets on reload.

What & Where

WHAT? — What failed?
WHERE? — Exactly where?
0 / 2 complete

When & Extent

WHEN? — When did it occur?
EXTENT? — How much of the system is affected?
0 / 2 complete

Impact & Status

IMPACT? — What operational capability may be affected?
STATUS? — Is it under repair?
0 / 2 complete

Restoration & Evidence

RESTORATION? — When is it expected or confirmed?
EVIDENCE? — What measurements/tests confirm the condition?
0 / 2 complete
28, 29 & 30. Data Discipline

NOTAM Data Accuracy & Time Management

Incorrect NOTAM information can create operational confusion. Common information errors include:

Wrong runway designation Wrong taxiway Wrong lighting type Incorrect effective time Incorrect end time Incomplete affected area Failure to update restoration Failure to cancel an obsolete notice

Engineering should clearly record detection time, notification time, maintenance start, maintenance completion, testing completion and restoration confirmation — creating a traceable timeline. Aeronautical information commonly uses UTC for standardized time reporting; engineering records may use local time, but the responsible procedure should be followed when providing information for aeronautical information processing. A time-zone mistake can create an operationally significant error.

31. Lifecycle

The NOTAM Lifecycle

1. Detect

Identify the condition.

2. Verify

Confirm the technical condition.

3. Assess

Determine operational significance.

4. Report

Verified information to authorized function.

5. Publish

NOTAM issued if required.

6. Maintain

Repair and monitor.

7. Verify Restoration

Confirm serviceability.

8. Update/Cancel

Reflect the restored condition.

The planned order of work on a scheduled visit — plan and permit, look while live, isolate, clean, inspect and test, then restore, verify and record, so wear is found and fixed before a light fails.

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 10. The planned order of work on a scheduled visit — plan and permit, look while live, isolate, clean, inspect and test, then restore, verify and record, so wear is found and fixed before a light fails.
AGL Visual Encyclopedia: The preventive maintenance sequence
32 & 41. Decision Support

NOTAM Quality Control & the AGL NOTAM Decision Framework

Before information is passed to the authorized NOTAM function, check: correct airport, correct facility, correct runway/taxiway, correct lighting system, correct affected area, condition verified, start time recorded, expected restoration established if appropriate, maintenance team and operations informed, and supporting test records available.

Use This as an Internal Engineering Decision Aid

Step 1 — Is there an AGL abnormality? NO → Normal operation. YES → Continue.

Step 2 — Is the condition verified? NO → Investigate. YES → Continue.

Step 3 — Does it affect an aeronautical facility or operational capability? NO → Maintenance record. YES → Continue.

Step 4 — Is the condition operationally significant under applicable procedures? NO → Normal maintenance/control process. YES → Notify the authorized airport/AIS function.

Step 5 — Is NOTAM or another aeronautical information action required? Decision by authorized function.

Step 6 — Repair and verify.

Step 7 — Update/cancel the applicable information as required.

The Decision Framework as a Branching Path

Most abnormalities exit early as routine maintenance — only conditions that clear every gate reach the authorized NOTAM function

1. AGL ABNORMALITY? NO NORMAL OPERATION YES 2. CONDITION VERIFIED? NO INVESTIGATE YES 3. AFFECTS AERONAUTICAL FACILITY / CAPABILITY? NO MAINTENANCE RECORD YES 4. OPERATIONALLY SIGNIFICANT? NO NORMAL MAINTENANCE / CONTROL PROCESS YES NOTIFY AUTHORIZED AIS FUNCTION NOTAM ACTION DECIDED by authorized function REPAIR & VERIFY UPDATE / CANCEL PUBLISHED INFORMATION
42. Traceability

NOTAM Documentation Package

For significant AGL events, maintain a complete auditable chain from fault to restoration.

Fault report Photographs where appropriate Test results CCR readings Circuit measurements Insulation test results Fixture inspection Photometry where applicable Repair record Replacement records Restoration test Operations notification Aeronautical information communication Applicable NOTAM reference Cancellation/update record
35. Learn From Others' Mistakes

Common NOTAM-Related Mistakes

Click a card to expand it.

Mistake 1

Wrong Assumption

  • Assuming every AGL fault requires a NOTAM.

Mistake 2

Under-Reporting

  • Failing to report an operationally significant lighting outage.

Mistake 3

Unverified Reporting

  • Giving an unverified technical description.

Mistake 4

Location Error

  • Using the wrong runway/taxiway identifier.

Mistake 5

Time Error

  • Using incorrect effective times.

Mistake 6

Stale Notice

  • Failing to update the notice after restoration.

Mistake 7

Premature Restoration

  • Considering a repaired fixture automatically restored without required verification.

Mistake 8

Terminology Confusion

  • Confusing maintenance records with NOTAMs.

Mistake 9

Coordination Gap

  • Ignoring operational coordination during planned maintenance.

Mistake 10

Broken Traceability

  • Failing to maintain traceability between the technical defect and operational notification.
47. Terminology Discipline

NOTAM vs NOTAM-Like Internal Alerts

Don't mix terminology. An airport may have internal maintenance alerts, engineering notifications, operations alerts, control-room alarms or work permits — these are not necessarily NOTAMs. A NOTAM is part of the formal aeronautical information framework.

48. Worked Example

Practical AGL Scenario

Scenario: A runway edge-lighting circuit develops a fault during night operations.

1

Detect

CCR/circuit alarm or visual report.

2

Verify

Engineer confirms the affected circuit.

3

Identify

Determine affected runway and lighting section.

4

Notify

Inform airport operations according to procedure.

5

Assess

Authorized personnel determine operational significance.

6

Aeronautical Information

Applicable NOTAM action is taken if required.

7

Repair

Fault is isolated and rectified.

8

Test

Electrical and functional tests completed.

9

Verify

Required system performance confirmed.

10

Restore

Responsible function updates/cancels applicable information.

36. Troubleshooting Link

NOTAM and Troubleshooting

Your AGL Troubleshooting Engine can connect technically to the NOTAM workflow. This should be a decision-support pathway, not an automatic NOTAM generator.

Symptom
Equipment
Fault
Affected Circuit
Affected Lighting System
Operational Impact
Notify Responsible Airport Function

Match the symptom to the likely places in the loop, then narrow the fault down by section with the circuit isolated.

SERIES-CIRCUIT TROUBLESHOOTING · SYMPTOM TO LIKELY PLACECCRABCDESERIES LOOPsame current through every lightA CABLE · B JOINT · C CONNECTOR · D ISOLATION TRANSFORMER · E FIXTUREALL LIGHTS OUTA B C · open circuit · continuity by sectionCCR TRIPS, EARTH FAULTA B C D · low insulation · IR by sectionSOME LIGHTS OUTD E C · local fault · test that deviceDIM, LOW CURRENTA B C D · leakage or load · compare with stepFLICKERING, INTERMITTENTB C A · loose or wet · inspect when isolatedALWAYSTELL ATC · ISOLATE AND LOCK OFF THE CCR · AUTHORISED PERSONNEL ONLYSeries circuits carry high current. Use the fault-isolation flowchart to narrow the fault to one section.
Figure 11. Match the symptom to the likely places in the loop, then narrow the fault down by section with the circuit isolated.
AGL Visual Encyclopedia: How do you troubleshoot a series circuit
37. Maintenance Systems

NOTAM and Maintenance Management

A mature AGL maintenance system should connect the fault through to the applicable notice, creating a complete traceable workflow:

FAULT LOG
WORK ORDER
TECHNICAL INSPECTION
OPERATIONAL IMPACT
AERONAUTICAL INFORMATION PROCESS
REPAIR
TESTING
RESTORATION
NOTICE UPDATE/CANCELLATION

Using condition data and trends to forecast when equipment needs attention — so work is done before failure, but not before it is needed.

PREDICTIVE MAINTENANCE · ACT ON CONDITION, BEFORE FAILURE FORECAST THE FAULT, THEN PLAN THE FIX PLANNED WORK WINDOW GOOD POOR TIME → EQUIPMENT CONDITION ALERT LEVEL FAILURE LEVEL ACTUAL READINGS FORECAST IF NOTHING IS DONE 1 TREND SPOTTED readings drift from normal 2 FIXED ALARM would only fire here 3 REPAIR PLANNED done before failure A FORECAST IS AN ESTIMATE: CHECK IT, KEEP REQUIRED INSPECTIONS, KEEP THE LIGHTING AVAILABLE SCHEMATIC · ILLUSTRATIVE CURVE · NOT TO SCALE · REAL TRENDS VARY
Figure 12. Using condition data and trends to forecast when equipment needs attention — so work is done before failure, but not before it is needed.
AGL Visual Encyclopedia: Predictive maintenance
44, 45 & 46. Engineering Improvement

From NOTAM to Reliability Improvement

Repeated NOTAM events for the same equipment should trigger engineering analysis. A NOTAM should not always be treated as the end of the process.

Watch For Recurrence

Repeated PAPI outage → repeated CCR fault → repeated transformer failure → repeated connector failure → repeated cable earth fault may indicate a deeper reliability issue.

  • Failure frequency
  • Failure duration
  • Equipment type & location
  • Root cause
  • Restoration time
  • Recurrence

Trend Analysis

A mature airport maintenance system tracks the number of AGL-related operational notices against:

  • Runway / taxiway
  • Equipment, manufacturer, component
  • Failure mode
  • Month, weather, maintenance activity
OPERATIONAL NOTICE
MAINTENANCE EVENT
ROOT-CAUSE ANALYSIS
RELIABILITY IMPROVEMENT
PREVENTIVE ACTION
REDUCED RECURRENCE
43. Roles

NOTAM and AGL Engineering Responsibility

AGL Technician

Detects and reports the technical condition.

AGL Engineer

Verifies, diagnoses and documents the condition.

Maintenance Control

Coordinates repair and operational communication.

Airport Operations / ATC

Assesses operational implications per airport procedures.

AIS / NOTAM Authority

Processes and publishes the aeronautical information as required.

The exact responsibilities vary by airport and State.
39. Emergency Response

NOTAM and Emergency Response

For critical AGL failures, the engineering team should never delay an urgent operational notification simply because complete root-cause analysis is still underway. The initial communication should accurately describe the known verified condition.

Detect
Verify
Immediately Notify Operations
Protect the Operational Area
Technical Investigation
Aeronautical Information Action as Required
Repair
Test
Restore

Making a series lighting circuit safe to work on — supply locked out, loop disconnected at the CCR, then proved dead and earthed.

SERIES LOOP · CIRCUIT ISOLATION BEFORE WORK NEVER BREAK A LIVE SERIES LOOP · ISOLATE FIRST SUPPLY ISOLATOR OPEN · LOCKED CCR OFF OUT RTN T1 T2 T3 T4 WORK POINT 0 V 1CCR OFF · SUPPLY ISOLATED AND LOCKED OUT 2LOOP DISCONNECTED AT THE CCR OUTPUT 3PROVED DEAD · EARTHED EACH SIDE OF WORK ISOLATED · LOCKED OUT · PROVED DEADSAFE TO WORKNo source can re-energise the loop NOT ISOLATED OR NOT PROVEDLIVE LOOPShock and arc risk; never break a live circuit SCHEMATIC · LOOP SHORTENED · NOT TO SCALE
Figure 13. Making a series lighting circuit safe to work on — supply locked out, loop disconnected at the CCR, then proved dead and earthed.
AGL Visual Encyclopedia: Circuit isolation
40. The Bigger Picture

NOTAM and Safety Management

NOTAMs form part of a broader operational safety system. They help ensure that aviation users are informed when aerodrome conditions differ from expected conditions. For AGL engineering, this creates the principle: a defect that changes operational capability must be communicated through the airport's approved safety and aeronautical information process.

49. The Core Principle

The Most Important NOTAM Principle for AGL Engineers

Do not think of a NOTAM as a document created after a failure. Think of it as part of the operational safety response to a change in aerodrome conditions. The engineering responsibility is to provide information that is:

Accurate
Verified
Timely
Specific
Traceable
50. Reference Framework

NOTAM Standards & References

NOTAM procedures are governed by the applicable international and national aeronautical information framework. For India, the exact NOTAM workflow, authority and publication requirements should be checked against the current applicable DGCA/AIS framework and airport procedures — never rely on an old NOTAM format or procedure simply because it appears in a historical document.

ICAO

Annex 15, Aeronautical Information Services; Annex 14, Aerodromes.

PANS-AIM

ICAO Procedures for Air Navigation Services — Aeronautical Information Management.

DGCA / State AIS

Applicable State AIS/NOTAM regulations and DGCA requirements in India.

Airport Manuals

Airport Operations Manual, Aerodrome Manual, local NOTAM procedures, AGL maintenance and emergency procedures.

ICAO Standards Companion Indian / DGCA Framework
Test Yourself

Quick Knowledge Check

Q1. A NOTAM is best described as:

A. An internal engineering maintenance record
B. An operational safety communication
C. A weather report
D. A CCR fault log

Q2. A PAPI unit is illuminated. What does this confirm on its own?

A. It is correctly aligned
B. It meets photometric requirements
C. Only that it is electrically energised
D. That a NOTAM is not required

Q3. Who is normally authorized to decide on and issue a NOTAM?

A. The authorized aeronautical information / airport function, per applicable procedure
B. Any AGL technician who finds a fault
C. The equipment manufacturer
D. Whoever is on shift at the time

Q4. A single failed runway edge fixture out of many is found. What should happen first?

A. Automatically request a NOTAM
B. Ignore it until the next inspection
C. Issue a SNOWTAM
D. Determine location, extent and operational significance before deciding next steps
51. Explore More

NOTAM Knowledge Hub — Related AGL Topics

AGL Testing & Inspection

Verify the technical condition before reporting restoration.

Explore →

AGL Installation & Commissioning

Understand operational coordination during installation and commissioning.

Explore →

AGL Troubleshooting Engine

Identify and isolate AGL failures.

Explore →

AGL Photometry

Verify optical performance where applicable.

Explore →

Runway Lighting Systems

Understand the operational importance of runway lighting.

Explore →

Taxiway Lighting Systems

Understand lighting requirements for aircraft ground movement.

Explore →

PAPI Engineering Guide

Understand PAPI failures, alignment and restoration.

Explore →

AGL Maintenance Handbook

Connect failure reporting with preventive and corrective maintenance.

Explore →

AGL Case Studies

Study real-world operational and engineering events.

Explore →
52. Full Workflow

Complete AGL NOTAM Workflow

DETECT
VERIFY
IDENTIFY
ASSESS
REPORT
PUBLISH
MAINTAIN
TEST
VERIFY
UPDATE / CANCEL

Detect the AGL abnormality → verify the actual technical condition → identify the exact affected facility and location → assess potential operational significance → report verified information to the responsible airport function → authorized personnel publish the required aeronautical information → maintain by repairing and monitoring → test to confirm technical restoration → verify operational serviceability → update or cancel so published information reflects the restored condition.

The Final Principle

53. Final Engineering Principle

AGL Failure → Operational Impact → Verified Information → Authorized Notification → Corrective Action → Verified Restoration.

A NOTAM does not repair an AGL system. It communicates an operationally significant condition while the technical team works to restore the facility. For AGL engineers, the objective is not merely "issue a NOTAM." The objective is to identify the real condition, communicate it accurately through the approved process, restore the system correctly, verify serviceability, and ensure the aeronautical information remains current.

Accurate. Timely. Traceable.

NOTAMs turn a verified AGL condition into a safety communication aviation users can act on. Explore the reporting discipline, decision framework and standards behind it.

Explore AGL Knowledge Hub AGL Engineering Services AGL Troubleshooting Engine
Keyword Reference

Airfield Lighting NOTAM Procedure

Airfield lighting NOTAM procedure

The airfield lighting NOTAM procedure begins when a lighting fault or planned work affects what pilots can rely on. The AGL team reports the facts to the airport operations office, which decides whether a NOTAM is needed and issues it through the authorised channel. When the system is repaired and checked, the same route is used to cancel or amend the NOTAM. Follow your aerodrome's own procedure and the aviation authority's rules.

AGL Engineering Hub

Explore the AGL Engineering Knowledge Hub

Fundamentals

All About AGL How Airfield Lighting Works Physics of AGL AGL Components Airfield Lighting Colour Codes LED Airfield Ground Lighting LED Benefits, Lifespan & Energy Savings Solar AGL (SAGL) Portable AGL (PAGL) Advantages & Disadvantages by System Type Sustainability in AGL

Standards & Compliance

ICAO Annex 14 AGL Requirements ICAO Aerodrome Lighting Requirements FAA AC 150/5340 Series EASA CS-ADR-DSN Compliance NOTAMs

Runway, Taxiway & Approach Lighting

Runway Lighting Systems Taxiway Lighting Systems Airport Approach Lighting Systems Approach Lighting Systems Apron Lighting & Stand Guidance Apron Floodlighting Design & Lux Levels VDGS: Visual Docking Guidance Obstruction Lighting & Marking Airfield Signage & Guidance Signs Markings & Signage Integration

Surface Movement & Safety

Follow the Greens Runway Guard Lights & Stop Bars Runway Incursion Prevention & SMGCS A-SMGCS ALCMS

PAPI

How Does PAPI Work? PAPI Engineering Guide ICAO PAPI Requirements PAPI Installation & Aiming PAPI Calibration & Alignment PAPI Alignment & Maintenance PAPI Maintenance Checklist

Electrical Engineering & Power

AGL Design & Electrical Engineering Diagrams, Schematics & Wiring CCR Working Principle CCR Deep Dive AGL Isolating Transformers Airport Isolating Transformer Junction Box & Transformer Housing Cables & Connector Engineering Electrical Architecture & Redundancy Emergency Backup Power Emergency Power & Lighting Systems Surge Protection & Lightning Mitigation Lightning & Surge Protection for Circuits

Photometry & Testing

AGL Photometry Photometric Testing Guide Photometric Testing Procedure Runway Lighting Photometry Taxiway Lighting Photometry AGL Testing & Inspection Installation & Commissioning Testing & Commissioning Guide

Maintenance, Inspection & Safety

Preventive & Corrective Maintenance Maintenance Schedule & Checklist Inspection, Maintenance & Audit Checklists How to Inspect & Replace Airfield Lights Common Failure Causes & Fixes Outage Response & Runway Closure Maintenance Work Safety: LOTO, Permits, PPE

Resources, Documentation & Careers

Datasheets, Catalogues & PDF Guides Project Documentation: ITP, As-Built, O&M Engineer & Technician Job Description / Salary
FAQ

Frequently Asked Questions

Q1What is a NOTAM?

NOTAM stands for Notice to Airmen. It communicates the establishment, condition, change or removal of an aeronautical facility, service, procedure or hazard when that information is timely and operationally significant. The circumstances requiring one are determined by applicable aeronautical information regulations and the responsible authority, not by an individual engineer's judgement alone.

Q2Why do NOTAMs matter for airfield ground lighting?

An AGL defect can be more than a maintenance problem, since it can change the visual guidance an aircraft actually receives. Engineering identifies and communicates the technical condition through the airport's reporting process, and the authorized aeronautical information function determines and issues the operational notice.

Q3What is the difference between a NOTAM and a maintenance report?

A maintenance report is a technical record for engineering and maintenance use, containing technical details of inspections or failures. A NOTAM is operational information for aviation users, using standardized aeronautical information published through authorized channels. One should not be treated as automatically equivalent to the other.

Q4Who decides whether a NOTAM is issued for an AGL fault?

Authorized operational and aeronautical information personnel determine and issue the notice. Engineering identifies and verifies the condition and reports it through the established process.

Q5When can an AGL problem become NOTAM-relevant?

It depends on operational significance and the applicable procedures, not simply on a fault existing. Examples include unavailable or partially unavailable runway lighting, affected taxiway lighting or stop bars, unavailable or degraded approach lighting, PAPI outages or restrictions, and unavailable airfield signs. The governing question is whether the condition changes published or expected operational conditions.

Q6What is the AGL-to-NOTAM chain?

AGL fault, detection, technical verification, operational impact assessment, report to the authorized airport function, NOTAM decision, NOTAM issuance, maintenance or rectification, verification, and finally NOTAM cancellation or update.

Q7Does a lit PAPI mean it is serviceable?

No. A PAPI that is physically illuminated is not necessarily operationally correct. A powered, visibly lit PAPI can still present a false glide-path indication, where the fault is optical rather than electrical, so technical verification should accompany operational reporting.

Q8How precisely should approach lighting faults be reported?

Identify exactly which portion of the system is affected, such as centreline lighting, crossbars, sequenced flashing components or other elements, rather than simply reporting that the approach lights are faulty.

Q9What should happen during an emergency AGL failure?

Speed matters, but accuracy matters equally. Confirm the condition, notify airport operations, assess the operational impact, initiate the applicable aeronautical information procedure, then rectify, test, restore and update or cancel the notice. Never communicate an unverified technical assumption as an operational fact.

Q10How is planned AGL maintenance coordinated with NOTAMs?

The workflow runs from the maintenance plan and identification of affected AGL, through operational impact assessment and coordination with airport operations, ATC and AIS, to any required notice or restriction, then the maintenance work, testing, restoration and notice cancellation or update if applicable.

Field Insight

Engineering & Expert Notes

RS
By Rahul Sharma
Airfield Ground Lighting Specialist
A Fault Log Is Not a NOTAM
Principle

Understand when a maintenance finding affects operations and needs to be notified.

Timeliness Matters
Timing

Start notification promptly and follow your airport's procedure for who issues it.

Light On Does Not Mean Compliant
PAPI and AGL

A light that is on may be misaligned or degraded. Consider whether the function is actually available.

Be Clear and Specific
Wording

Describe what is unavailable and where. Vague wording leaves operators guessing.

Cancel and Update Accurately
Updates

Keep information current as work progresses and when the facility is returned to service.

Record the Chain of Decisions
Records

Keep a record of the engineering input, decision and issue time for later review.

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