Division 18 · APL · Structural, Optical & Electrical Integrity

Approach Lighting Maintenance

Dedicated maintenance procedures for the complete approach lighting system — fixtures, light bars, poles, crossbars, structural members, foundations, frangible components, electrical connections, and associated isolation transformers. The objective is to preserve the geometry and continuity of the whole system, not just the operation of individual fixtures.

Core principle: Physical Integrity + Frangibility + Electrical Integrity + Geometric Accuracy + Optical Performance = Acceptable Approach Lighting Condition. A fixture can be electrically functional and still require maintenance because of incorrect alignment, incorrect elevation, structural movement, corrosion, vegetation obstruction, or a damaged frangible component.

Safety before work: isolate and lock out the affected series circuit at the CCR before touching fixtures, connectors or isolation transformers — never open a live series circuit or disconnect a primary connector on an energised circuit. Obtain airside / ATC work authorisation, and apply working-at-height controls for poles and structures.

36
Topics in Division
03
Topic Groups (A–C)
05
Integrity Factors
10
Step Maintenance Sequence

Maintenance Sequence

Every approach-lighting maintenance task in this division follows the same underlying sequence, and every intervention is judged against the same five integrity factors.

Inspect
Clean
Check Structure
Check Electrical System
Check Alignment
Check Elevation
Verify Visibility
Verify Illumination
Restore
Record
Physical integrity Frangibility Electrical integrity Geometric accuracy Optical performance

Troubleshooting Flow

Recommended diagnostic path for a defective approach light, from initial observation through to record.

Light OFF / abnormal
Visual fixture inspection
Check lamp/LED
Check optical component
Check secondary lead
Check connector
Check isolation transformer
Check circuit/cable
Correct defect
Test
Check alignment
Check elevation
Verify illumination
Record

Maintenance Decision Matrix

Quick-reference mapping from inspection finding to typical maintenance action.

FindingTypical Action
Dirty fixtureClean
Damaged fixtureRepair/replace
Failed lamp/LEDReplace
Damaged lens/prismReplace
Misaligned fixtureRealign
Incorrect elevationCorrect
Loose mountingTighten (to specified torque)
Damaged frangible componentReplace
Corroded structureAssess/treat/replace
Damaged poleRepair/replace
Damaged crossbarRepair/replace
Foundation deteriorationAssess/repair
Cable damageRepair/replace
Connector damageReplace
Transformer faultRepair/replace
Water ingressIdentify source/correct
Vegetation obstructionClear
Storm damageInspect/restore
Vehicle impactIsolate/inspect/repair
Construction displacementRestore geometry
Illumination abnormalityInvestigate/correct

The 36 Topics

Grouped by maintenance category — click any topic to expand its maintenance activities and acceptance condition.

A

Preventive Maintenance

18 topics
MNT-APL-001Approach Light Fixture Cleaning
Removes
  • Dust
  • Dirt
  • Mud
  • Insects
  • Other contamination
Acceptance / Record

Standard: cleaning must not damage lens, prism, optical surfaces, housing, or seals — verify fixture condition after cleaning.

MNT-APL-002Approach Fixture Inspection
Inspect For
  • Physical damage
  • Housing condition
  • Optical condition
  • Mounting condition
  • Alignment
  • Cable/connector condition
  • Corrosion
  • Water ingress
Acceptance / Record

Action: record defective fixtures for corrective maintenance.

MNT-APL-003Light-Bar Inspection
Inspect For
  • Structural condition
  • Fixture mounting
  • Alignment
  • Corrosion
  • Physical deformation
  • Loose components
  • Cable routing
Acceptance / Record

Attention: damage that could alter the designed approach-lighting geometry.

MNT-APL-004Pole Inspection
Inspect For
  • Physical damage
  • Corrosion
  • Deformation
  • Loose components
  • Mounting condition
  • Frangible arrangement
Acceptance / Record

Standard: assess any abnormal structural condition before the installation returns to normal service.

MNT-APL-005Crossbar Inspection
Inspect For
  • Physical damage
  • Deformation
  • Corrosion
  • Loose connections
  • Fixture mounting
  • Structural stability
Acceptance / Record

Verify: fixtures remain correctly positioned.

MNT-APL-006Structure Inspection
Check
  • Structural members
  • Connections
  • Mounting points
  • Corrosion
  • Damage
  • Stability
  • Alignment
MNT-APL-007Foundation Inspection
Inspect For
  • Cracking
  • Physical damage
  • Settlement
  • Exposed components
  • Loose mounting arrangements
  • Water accumulation
  • Signs of structural movement
Acceptance / Record

Standard: refer significant deterioration for appropriate engineering assessment.

MNT-APL-008Frangible Component Inspection
Inspect For
  • Damage
  • Deformation
  • Corrosion
  • Incorrect installation
  • Missing components
  • Evidence of impact
Acceptance / Record

Never: replace a frangible component with an ordinary rigid component unless specifically approved by the applicable design requirements. Use only the specified fasteners and tightening torque — over-tightening or substituting fasteners can compromise frangibility.

MNT-APL-009Fixture Alignment Inspection
Check For
  • Horizontal displacement
  • Angular displacement
  • Rotation
  • Loose mounting
  • Structural movement
Acceptance / Record

Standard: check alignment against the approved system/design requirements.

MNT-APL-010Fixture Elevation Inspection
Check For Changes Caused By
  • Settlement
  • Structural movement
  • Foundation deterioration
  • Maintenance work
  • Accidental impact
Acceptance / Record

Standard: correct any abnormal elevation — mounting height and vertical aiming angle / level — using the approved method.

MNT-APL-011Cable Inspection
Inspect For
  • Physical damage
  • Exposed sections
  • Poor routing
  • Mechanical stress
  • Water ingress
  • Deterioration
  • Identification
Acceptance / Record

Attention: areas exposed to environmental or mechanical damage.

MNT-APL-012Connector Inspection
Inspect For
  • Physical damage
  • Loose connection
  • Corrosion
  • Moisture ingress
  • Seal condition
  • Cable-lead condition
Acceptance / Record

Standard: repair/replace defective connectors per applicable connector requirements.

MNT-APL-013Isolation-Transformer Inspection
Inspect For
  • Physical condition
  • Housing condition
  • Cable leads
  • Connector condition
  • Water ingress
  • Corrosion
  • Mechanical damage
Acceptance / Record

Where located in pits: inspect the associated pit condition as well.

MNT-APL-014Water-Ingress Inspection
Check For
  • Water entry
  • Moisture
  • Condensation
  • Damaged seals
  • Poor cable-entry sealing
Acceptance / Record

Where identified: identify source, remove moisture, correct sealing, inspect and test affected equipment.

MNT-APL-015Corrosion Inspection
Inspect
  • Fixtures
  • Poles
  • Crossbars
  • Structural members
  • Fasteners
  • Connectors
  • Transformer components
Acceptance / Record

Standard: where corrosion affects structural or electrical integrity, initiate corrective maintenance.

MNT-APL-016Vegetation Clearance
Inspect For
  • Vegetation obstructing fixtures
  • Vegetation affecting visibility
  • Vegetation interfering with structures
  • Vegetation affecting access
  • Vegetation creating maintenance hazards
Acceptance / Record

Coordinate: vegetation control with applicable airport environmental and airside requirements.

MNT-APL-017Approach Lighting Visibility Inspection
Check For
  • Vegetation
  • Construction equipment
  • Temporary structures
  • Debris
  • Other obstructions
Acceptance / Record

Objective: ensure the intended approach-lighting visual pattern remains available.

MNT-APL-018Illumination Condition Verification
Check For
  • Failed lights
  • Abnormally dim lights
  • Uneven illumination
  • Incorrect fixture operation
  • Optical contamination
  • Damaged optical components
Acceptance / Record

Standard: where formal photometric testing is required, perform it under the applicable procedure rather than relying solely on visual inspection.

B

Corrective Maintenance

13 topics
MNT-APL-019Approach Fixture Replacement
After Replacement, Verify
  • Mounting
  • Alignment
  • Elevation
  • Cable/connector
  • Illumination
  • Post-maintenance inspection complete
Acceptance / Record

Standard: replace damaged or failed fixtures when repair is not appropriate.

MNT-APL-020Lamp/LED Replacement
After Replacement, Verify
  • Correct installation
  • Illumination
  • Optical orientation
  • Fixture operation
Acceptance / Record

Standard: replace failed lamps or LED modules with approved components only.

MNT-APL-021Lens/Prism Replacement
After Replacement
  • Confirm correct component
  • Confirm proper installation
  • Clean optical surfaces
  • Verify alignment
  • Verify illumination
MNT-APL-022Pole Repair
Assess
  • Structural integrity
  • Alignment
  • Corrosion
  • Mounting
  • Frangibility
Acceptance / Record

Standard: repair only where permitted by the approved maintenance/design requirements.

MNT-APL-023Crossbar Repair
After Repair, Verify
  • Structural condition
  • Fixture mounting
  • Geometry
  • Alignment
MNT-APL-024Structure Repair
Must Not Unintentionally Alter
  • Position
  • Elevation
  • Alignment
  • Frangibility
Acceptance / Record

Standard: repair should follow an appropriate engineering assessment.

MNT-APL-025Frangible Component Replacement
After Replacement, Verify
  • Installation
  • Orientation
  • Mechanical security
  • Required frangible arrangement
Acceptance / Record

Standard: replace with the approved type only.

MNT-APL-026Cable Repair
After Repair
  • Verify connection
  • Verify insulation condition as applicable
  • Verify continuity
  • Restore mechanical protection
  • Complete post-maintenance testing
Acceptance / Record

Standard: repair using the approved repair method.

MNT-APL-027Connector Replacement
After Replacement, Verify
  • Mating
  • Locking
  • Sealing
  • Cable lead
  • Electrical continuity
MNT-APL-028Transformer Replacement
After Replacement, Verify
  • Rating
  • Connections
  • Positioning
  • Cable leads
  • Connector
  • Applicable electrical testing performed
Acceptance / Record

Standard: replace with approved units only.

MNT-APL-029Foundation Repair
After Repair, Verify
  • Structural stability
  • Fixture/pole position
  • Elevation
  • Alignment
Acceptance / Record

Standard: repair should follow appropriate engineering requirements.

MNT-APL-030Alignment Correction
Verification Sequence
  • Position
  • Elevation
  • Orientation
  • Mounting security
Acceptance / Record

Performed: when inspection identifies a deviation.

MNT-APL-031Damaged Structure Replacement
Following Replacement, Verify
  • Geometry
  • Frangibility where applicable
  • Fixture position
  • Electrical connections
  • Functional verification performed
Acceptance / Record

Standard: used where repair is not suitable — replace with approved components only.

C

Special Maintenance

5 topics
MNT-APL-032Post-Storm Approach Lighting Inspection
Look Specifically For
  • Wind damage
  • Structural movement
  • Water ingress
  • Flooding
  • Broken fixtures
  • Loose components
  • Electrical damage
Acceptance / Record

Inspect: fixtures, poles, crossbars, structures, foundations, frangible components, cables, connectors, transformers.

MNT-APL-033Post-Vehicle-Impact Inspection
Sequence
  • Isolate affected equipment/circuit as required
  • Establish the damaged area
  • Inspect structural and frangible components
  • Inspect fixtures, cables, connectors, transformer
  • Assess foundation
  • Repair/replace damaged components
  • Perform electrical and functional testing
  • Verify alignment and restore the system
MNT-APL-034Post-Construction Restoration
Inspect For
  • Displaced fixtures
  • Changed elevation
  • Cable damage
  • Damaged foundations
  • Structural disturbance
  • Vegetation/obstruction changes
  • Connector/transformer disturbance
Acceptance / Record

Standard: restore the system to the approved configuration.

MNT-APL-035Approach Lighting System Restoration
Confirm
  • Fixtures operational and correctly aligned
  • Structures secure
  • Frangible components correctly installed
  • Cables intact
  • Connectors secure
  • Transformers serviceable
  • Visibility satisfactory
  • Illumination satisfactory
MNT-APL-036Post-Maintenance Functional Verification
Verify As Applicable
  • Mechanical — fixture, pole, crossbar, structure, foundation, frangible
  • Electrical — cable, connector, transformer, continuity, insulation testing
  • Optical — orientation, alignment, elevation, illumination
  • Environmental — water ingress, corrosion, vegetation clearance
  • Final — system operation, visibility, maintenance record
Acceptance / Record

Standard: this is a mandatory closure activity for every maintenance intervention.

Verification Categories

Post-maintenance functional verification is checked across five categories before any approach-lighting task is closed out.

1
Mechanical

Fixture mounting, pole, crossbar, structure, foundation, frangible components.

2
Electrical

Cable, connector, transformer, continuity, applicable insulation testing.

3
Optical

Fixture orientation, alignment, elevation, illumination.

4
Environmental

Water ingress, corrosion, vegetation clearance.

5
Final

System operation, visibility, maintenance record.

Frequently Asked Questions

Quick answers about approach lighting maintenance, based on the topics in this division.

8 QUESTIONS
Q1What is approach lighting maintenance in the AGL Maintenance Handbook?

It provides dedicated procedures for the complete approach lighting system: fixtures, light bars, poles, crossbars, structural members, foundations, frangible components and electrical connections.

Q2What does Division 18 of the AGL Maintenance Handbook cover?

Division 18 (Approach Lighting Maintenance) contains 36 topics in three groups: Group A Preventive Maintenance (18 topics), Group B Corrective Maintenance (13 topics) and Group C Special Maintenance (5 topics).

Q3What makes an approach lighting condition acceptable?

Five integrity factors together: physical integrity, frangibility, electrical integrity, geometric accuracy and optical performance. A fixture can be electrically functional and still not be acceptable.

Q4What safety rule applies before work on approach lighting?

Isolate and lock out the affected series circuit at the CCR before touching fixtures, connectors or isolation transformers, and never open a live series circuit.

Q5What is the approach lighting maintenance sequence?

Ten steps: Inspect, Clean, Check Structure, Check Electrical System, Check Alignment, Check Elevation, Verify Visibility, Verify Illumination, Restore and Record.

Q6How should a defective approach light be troubleshot?

Start with a visual fixture inspection, then check the lamp or LED, optical component, secondary lead, connector, isolation transformer and circuit or cable. Correct the defect, test, check alignment and elevation, verify illumination and record.

Q7What does the maintenance decision matrix recommend?

A dirty fixture is cleaned, a failed lamp or LED is replaced, a misaligned fixture is realigned, incorrect elevation is corrected, loose mounting is tightened to the specified torque, a damaged frangible component is replaced, vegetation is cleared, vehicle impact is isolated, inspected and repaired, and construction displacement means restoring the geometry.

Q8What verification is required before a task is closed?

Five categories: mechanical (mounting, pole, crossbar, structure, foundation, frangible components), electrical (cable, connector, transformer, continuity and applicable insulation testing), optical (orientation, alignment, elevation, illumination), environmental (water ingress, corrosion, vegetation clearance) and final (system operation, visibility and the maintenance record).

Go Further

Don't Just Maintain the Bars. Protect the Approach.

Approach lighting maintenance is more than checking individual light bars.

Build the technical knowledge to understand configuration integrity, structural condition, sequenced flashing systems, and how the approach array guides a pilot in low visibility.

Maintain the array. Protect the guidance. Understand the approach.

Build Practical AGL Approach Lighting Maintenance Capability
AGL Fundamentals Components Electrical Systems Preventive Maintenance Inspection Testing Photometry Troubleshooting Commissioning

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