Division 02 · CRR · Defect-Driven Repair Strategy

Corrective Maintenance

The defect-driven counterpart to Division 01. Corrective maintenance begins when an inspection, failure, test result or abnormal condition identifies a defect requiring diagnosis, repair, replacement, testing and restoration — carried out to return AGL equipment to full, verified service.

Philosophy: a corrective-maintenance job is not complete simply because the defective component has been physically replaced. The full cycle establishes that the original defect is corrected, the equipment is correctly reassembled and connected, it functions correctly, the work area is restored, any associated defect is addressed, and records are completed.

34
Topics in Division
04
Asset Groups (A–D)
04
Defect Classifications
10
Step CM Sequence

CM Philosophy

Every corrective-maintenance task in this division follows the same underlying sequence, regardless of asset type — from initial detection through to closure and trend review.

Detect
Assess
Diagnose
Plan
Isolate
Repair/Replace
Test
Restore
Monitor
Close
Critical Major Minor Observation

Corrective Maintenance Priority

Every defect is classified consistently with the handbook's established framework, and the classification drives the response.

PriorityMeaningTypical Action
CriticalImmediate operational / safety significanceImmediate action
MajorSignificant degradation / failurePriority corrective action
MinorLimited impactPlanned repair
ObservationCondition requiring monitoringMonitor / trend

Defect Initiation

Corrective maintenance can originate from five sources, each feeding into the same assessment and repair cycle.

Routine Inspection

  • Defect found during scheduled, calendar-driven inspection
e.g. runway edge light found unserviceable

Detailed Inspection

  • Condition deterioration identified during a detailed asset inspection
e.g. isolation transformer insulation deterioration

Failure

  • Equipment fails during normal operation
e.g. CCR output fault

Test Result

  • An electrical or functional test returns a non-conforming result
e.g. cable test indicates unacceptable condition

Special Inspection

  • Lightning
  • Flooding
  • Severe weather
  • Accident / incident
  • Construction
  • Major maintenance

Defect Assessment Record

  • Asset ID, location, circuit, equipment type
  • Defect description and failure symptom
  • Date/time detected and source of defect
  • Operational and safety impact, required action, classification

The 34 Topics

Grouped by asset type — click any topic to expand its corrective activities and post-repair verification.

A

Lighting Fixtures

10 topics
MNT-CRR-001Failed Lamp Replacement
Procedure
  • Identify failed lamp
  • Confirm fixture and circuit
  • Isolate equipment where required
  • Remove defective lamp
  • Inspect lamp holder / contact arrangement
  • Inspect optical components
  • Install approved replacement lamp
  • Reassemble fixture
  • Perform functional check
  • Record replacement
Acceptance / Record

Note: the cause of failure should also be considered rather than simply replacing the lamp.

MNT-CRR-002Failed LED-Module Replacement
Procedure
  • Confirm failed LED module
  • Verify correct replacement part
  • Isolate equipment where required
  • Open fixture per approved procedure
  • Inspect wiring / connectors
  • Remove defective module
  • Install replacement module
  • Verify sealing
  • Reassemble and perform illumination check
  • Record component replacement
MNT-CRR-003Damaged Lens Replacement
Check
  • Type and size
  • Optical characteristics
  • Mounting
  • Sealing
Acceptance / Record

After replacement: lens installed → fixture sealed → alignment verified → illumination checked → record completed.

MNT-CRR-004Damaged Prism Replacement
Inspect
  • Prism damage
  • Optical surface
  • Mounting arrangement
  • Sealing
  • Correct orientation
Acceptance / Record

Replace with the approved component and verify optical performance / function after reassembly.

MNT-CRR-005Damaged Housing Repair
Damage May Include
  • Cracking
  • Deformation
  • Corrosion
  • Mechanical damage
  • Damaged sealing surfaces
Acceptance / Record

Decision: determine whether the housing is repairable or requires complete fixture replacement.

MNT-CRR-006Gasket Replacement
Procedure
  • Remove damaged gasket
  • Clean mating surfaces
  • Inspect sealing groove
  • Install correct gasket
  • Verify seating
  • Reassemble housing
  • Verify sealing
  • Perform functional check
MNT-CRR-007Mounting-Hardware Replacement
Replace
  • Bolts, nuts, washers
  • Mounting components
  • Associated hardware
Acceptance / Record

After replacement: secure fixture → verify alignment → verify stability → complete functional check.

MNT-CRR-008Frangible-Component Replacement
Check
  • Correct component type
  • Mechanical condition
  • Correct installation
  • Fixture alignment
  • Structural integrity
Acceptance / Record

After replacement: confirm the fixture is correctly restored.

MNT-CRR-009Secondary-Lead Replacement
Addresses
  • Damaged cable / insulation
  • Failed termination
  • Connector interface
  • Mechanical protection
Acceptance / Record

After replacement: verify connection, insulation condition, polarity / connection arrangement, and perform functional check.

MNT-CRR-010Complete Fixture Replacement
Required Where
  • Housing is beyond repair
  • Optical system is damaged
  • Internal components extensively damaged
  • Corrosion compromises integrity
  • Repeated failures indicate replacement
Acceptance / Record

Sequence: identify → isolate → remove → inspect interface → install → align → connect → test → restore → record.

B

Electrical Equipment

8 topics
MNT-CRR-011CCR Fault Repair
Check As Applicable
  • Input supply
  • Output current
  • Display and alarm
  • Protection and control system
  • Cooling and fans
  • Contactors and terminals
  • Control wiring and earth connection
  • Communication
Acceptance / Record

Root cause: the repair should address the root fault, not merely clear the alarm.

MNT-CRR-012CCR Component Replacement
Potential Replacements
  • Control components
  • Contactors and relays
  • Fans
  • Protection devices
  • Interface components
  • Other approved replaceable parts
Acceptance / Record

After replacement: component replaced → wiring verified → power restored → output checked → control checked → alarm checked → record.

MNT-CRR-013Isolation-Transformer Replacement
Procedure
  • Identify defective transformer, confirm rating
  • Isolate circuit
  • Disconnect primary and secondary
  • Remove and inspect pit / interface
  • Install replacement, connect primary / secondary
  • Verify connections
  • Perform required electrical testing
  • Restore circuit, functional check, record
MNT-CRR-014Connector Replacement
Replace Where There Is
  • Corrosion
  • Damaged contacts
  • Broken locking mechanism
  • Seal failure or overheating
  • Mechanical damage
  • Moisture ingress
Acceptance / Record

After replacement: verify connector, termination, sealing, locking, cable lead, and perform functional / electrical verification.

MNT-CRR-015Cable Repair
May Address
  • Damaged insulation
  • Mechanical damage
  • Localized cable defect
  • Damaged termination
  • Cable exposure
  • Water ingress where repair is appropriate
Acceptance / Record

Method: appropriate to the cable system and approved maintenance procedure.

MNT-CRR-016Cable-Joint Repair
Check
  • Joint condition
  • Sealing
  • Insulation
  • Mechanical protection
  • Water ingress
  • Connection integrity
Acceptance / Record

After repair: joint completed → sealing verified → electrical test → functional verification → record.

MNT-CRR-017Cable-Termination Repair
May Include
  • Re-termination
  • Connector replacement
  • Cable-end preparation
  • Contact replacement
  • Sealing restoration
Acceptance / Record

After repair: verify electrical and mechanical integrity.

MNT-CRR-018Earthing-Connection Repair
May Involve
  • Damaged conductor
  • Loose connection
  • Corroded connection
  • Damaged bonding connection
  • Broken connection
Acceptance / Record

After repair: verify mechanical connection, continuity where applicable, perform earth testing, record results.

C

AGL Systems

10 topics
MNT-CRR-019PAPI Fault Correction
Possible Corrective Actions
  • Lamp / LED fault
  • Optical component problem
  • Internal component failure
  • Cable / connector issue
  • Alignment issue
  • Power issue
Acceptance / Record

After repair: verify unit operation, alignment, elevation / beam condition, and complete required photometric verification.

MNT-CRR-020PAPI Alignment Correction
Procedure
  • Confirm the defect
  • Verify reference / approved setting
  • Adjust the unit
  • Secure mounting
  • Recheck alignment
  • Perform required verification and record final condition
MNT-CRR-021Airfield-Sign Repair
May Address
  • Housing / face damage
  • LED module failure
  • Driver failure
  • Wiring / connector issue
  • Mounting
  • Water ingress
Acceptance / Record

After repair: verify message, illumination, colour / visibility, mounting, and record.

MNT-CRR-022Sign LED-Module Replacement
Procedure
  • Identify failed module
  • Isolate
  • Remove and install approved module
  • Check wiring
  • Restore sealing
  • Test illumination and record
MNT-CRR-023Sign Driver Replacement
Check
  • Correct driver type
  • Electrical compatibility
  • Wiring and mounting
  • Protection and output
Acceptance / Record

After replacement: verify complete sign operation.

MNT-CRR-024Approach-Light Repair
May Address
  • Failed fixture
  • Damaged structure / pole
  • Cable / connector fault
  • Transformer fault
  • Alignment issue
  • Corrosion / mechanical damage
Acceptance / Record

After repair: verify structural condition, fixture alignment, illumination, cable / connection, and restore the area.

MNT-CRR-025Stop-Bar Repair
May Involve
  • Fixture replacement
  • LED / module replacement
  • Cable repair
  • Connector replacement
  • Mounting repair
  • Alignment correction
Acceptance / Record

After repair: verify illumination and operational function.

MNT-CRR-026Runway Guard Light Repair
May Include
  • Fixture repair / replacement
  • Lamp / LED replacement
  • Cable / connector repair
  • Alignment correction
  • Mounting repair
  • Control / flash-function correction
Acceptance / Record

Verify flashing operation where applicable.

MNT-CRR-027ALCMS Fault Correction
Corrective Troubleshooting
  • HMI problems
  • Communication failure
  • Control failure / PLC-interface fault
  • Network equipment fault
  • Remote-status failure
  • Alarm and data-logging issues
Acceptance / Record

After correction: fault identified → corrective action → communication verified → command verified → feedback verified → alarm verified → record.

MNT-CRR-028Control-System Component Replacement
Before Replacement
  • Identify failed component, verify part number
  • Confirm system compatibility
  • Preserve configuration / data where required
  • Isolate affected system
Acceptance / Record

After replacement: restore configuration, verify communication, command, feedback, alarms, and record.

D

Restoration

6 topics
MNT-CRR-029Defect Verification
Before Closing The Job, Verify
  • Original defect
  • Corrective action
  • Component replaced / repaired
  • Associated components
  • Cause where known
MNT-CRR-030Repair Verification
Verify
  • Mechanical integrity
  • Electrical connection
  • Optical condition
  • Alignment
  • Sealing and mounting
  • Identification
MNT-CRR-031Post-Repair Functional Check
Depending On Equipment
  • ON / OFF, brightness / intensity
  • Flashing
  • Remote control, alarm, feedback
  • Communication
  • Illumination
MNT-CRR-032Post-Repair Electrical Testing
Where Applicable
  • Continuity
  • Insulation resistance
  • Earth continuity / resistance
  • Circuit verification
  • Transformer testing
  • Other required electrical tests
MNT-CRR-033Return-to-Service Restoration
Before Return To Service
  • Repair and connections complete
  • Equipment secure, alignment correct
  • Functional test satisfactory
  • Required electrical tests satisfactory
  • Work area restored, FOD removed
  • Covers / labels restored
  • Documentation completed
  • Operational authority notified where required
MNT-CRR-034Corrective-Maintenance Record
Each Job Should Record
  • Identification, work order, asset / circuit ID, location, equipment type
  • Defect, date/time, source, failure description, classification, operational impact
  • Diagnosis, troubleshooting, cause, findings
  • Corrective action, repair performed, component / part / quantity, technician
  • Functional test, electrical test, alignment check, other verification
  • Closure, final condition, return-to-service date/time, supervisor, remarks, photographs

Root-Cause Consideration

A major improvement for this division is to avoid "replace and close" maintenance. For recurring failures, the diagnostic chain below is worked through before the job is closed.

What failed?
Why did it fail?
Was the component itself defective?
Was installation a factor?
Was moisture involved?
Was overheating involved?
Was electrical stress involved?
Was mechanical damage involved?
Was environmental exposure involved?
Is the failure recurring?
If recurring: the defect is escalated into condition assessment / corrective-action review.

Corrective Maintenance Workflow

The full lifecycle a defect moves through, from initial identification to trend review.

1
Defect Identified

Recorded and severity classified.

2
Impact Assessed

Operational impact assessed against the fault.

3
Diagnosis & Planning

Fault diagnosis and corrective action planned.

4
Isolation

Safety and isolation applied where required.

5
Repair / Replace

Corrective action carried out.

6
Verification

Electrical / mechanical verification and functional test.

7
Restoration

Area restoration and FOD removal.

8
Return to Service

Equipment restored to service.

9
Record Completion

Full record completed and defect closed.

10
Trend Review

Root-cause / trend review if the defect is recurring.

Key Principle for Division 02

A corrective-maintenance job is not closed when the component is replaced. It is closed only when the full chain below is complete — making Division 02 complementary to Division 01, and consistent with the Inspection Handbook, where inspection identifies and classifies the condition while maintenance performs the corrective action.

Defect Identified → Cause Assessed → Repair Completed → Equipment Tested → Function Verified → Area Restored → Returned to Service → Record Completed → Defect Closed

Frequently Asked Questions

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

8 QUESTIONS
Q1What is corrective maintenance in AGL?

Corrective maintenance is the defect-driven counterpart to preventive maintenance. It begins when an inspection, failure, test result or abnormal condition identifies a defect that needs diagnosis, repair, replacement, testing and restoration, so that AGL equipment is returned to full, verified service.

Q2What does Division 02 of the AGL Maintenance Handbook cover?

Division 02 (Corrective Maintenance) contains 34 topics in four groups: Group A Lighting Fixtures (10 topics), Group B Electrical Equipment (8 topics), Group C AGL Systems (10 topics) and Group D Restoration (6 topics).

Q3Is a corrective-maintenance job finished once the defective component is replaced?

No. The job is closed only when the full chain is complete: defect identified, cause assessed, repair completed, equipment tested, function verified, area restored, returned to service, record completed and defect closed. The full cycle establishes that the original defect is corrected, the equipment is reassembled and connected correctly, and any associated defect has been addressed.

Q4What is the standard corrective-maintenance sequence?

Every task follows the same ten-step sequence regardless of asset type: Detect, Assess, Diagnose, Plan, Isolate, Repair/Replace, Test, Restore, Monitor and Close.

Q5How are corrective-maintenance defects prioritised?

Every defect is classified as Critical (immediate operational or safety significance, immediate action), Major (significant degradation or failure, priority corrective action), Minor (limited impact, planned repair) or Observation (a condition needing monitoring, monitor and trend). The classification drives the response.

Q6Where do corrective-maintenance jobs come from?

Five sources feed the same assessment and repair cycle: routine inspection, detailed inspection, equipment failure, a non-conforming test result, and special inspection after events such as lightning, flooding, severe weather, an accident or incident, construction or major maintenance.

Q7What does 'replace and close' mean, and how does the handbook avoid it?

It describes replacing a failed part and closing the job without asking why it failed. For recurring failures the handbook works through a root-cause chain first: what failed, why, whether the component was defective, and whether installation, moisture, overheating, electrical stress, mechanical damage or environmental exposure was involved. If the failure is recurring, it is escalated into a condition assessment or corrective-action review.

Q8What should a defect assessment record contain?

It should capture the asset ID, location, circuit and equipment type; the defect description and failure symptom; the date and time detected and the source of the defect; and the operational and safety impact, required action and classification.

Go Further

Don't Just Fix the Fault. Understand Why It Failed.

Corrective maintenance is more than reacting to a reported defect.

Build the technical knowledge to diagnose root cause, apply the correct repair, verify restoration, and prevent the same failure from recurring across the airfield.

Diagnose with purpose. Repair with confidence. Prevent recurrence.

Build Practical AGL Corrective Maintenance Capability
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