The dedicated failure classification for approach-lighting systems — covering the complete chain from individual approach-light fixture failure through electrical, structural, optical, alignment, control and weather-related failures. Approach lighting differs from ordinary runway/taxiway lighting because failures can involve elevated structures, crossbars, poles, foundations and frangible components, in addition to the lighting/electrical system. Do not record an approach light simply as “failed.” Identify the failure mode, the affected component or structure, the technical mechanism, the operational consequence and the corrective action.
Key principle — Division 13 distinguishes component failure, structural failure, lighting-service failure and system-level failure. A failed light should never simply be logged as “approach light failed” — every record should trace the actual technical mechanism: what failed → how did it fail → why did it fail → what evidence confirmed it → how was it corrected → how can recurrence be prevented?
Failure of an individual approach-light fixture resulting in loss or degradation of its intended lighting function.
Failure or burnout of a lamp used in an approach-lighting fixture.
Failure or degradation of LED light sources used in approach-lighting fixtures.
Failure of the electronic driver supplying or controlling an LED approach-light fixture.
Failure of cables supplying or interconnecting approach-lighting equipment.
Cross-reference with Division 02 — Electrical Failures and Division 05 — Cable & Connector Failures where applicable.
Failure of connectors used within the approach-lighting electrical circuit.
Cross-reference with Division 05 — Cable & Connector Failures.
Failure of an isolation transformer or other transformer associated with an approach-lighting fixture/circuit.
Cross-reference with Division 04 — Isolation Transformer Failures.
Physical damage to an approach-lighting support structure.
Damage, deformation or failure of a crossbar supporting approach-light fixtures.
Damage, deformation or failure of poles supporting approach-lighting equipment.
Failure or deterioration of the foundation supporting approach-lighting structures.
Failure or damage of a frangible coupling/component intended to provide the required frangible characteristic of an approach-lighting structure.
Cross-reference with Division 06 — Mechanical & Structural Failures.
Approach-lighting fixture or supporting structure is no longer correctly aligned with its intended design position.
Deterioration of the optical performance of an approach-lighting fixture without necessarily producing a complete outage.
Entry of water or moisture into approach-lighting fixtures, transformers, connectors, structures or associated equipment.
Cross-reference with Division 09 — Environmental Failures.
Corrosion affecting approach-lighting fixtures, structures, poles, crossbars, fasteners, connectors or other components.
Failure of the electrical circuit supplying one or more approach-lighting fixtures.
Failure of the system used to control, monitor or select approach-lighting operation.
Cross-reference with Division 07 — Control System Failures.
Failure of multiple approach-light fixtures or sections during the same incident or related failure event.
Look for the common cause, rather than treating every failed fixture independently. For example:
Multiple approach-light failures should normally receive greater investigation priority than an isolated fixture failure because they may indicate a common-mode system vulnerability.
Approach-lighting equipment or structures are damaged or rendered unavailable due to severe environmental/weather conditions.
Cross-reference with Division 09 — Environmental Failures.
Standard record structure, failure-chain relationships, diagnostic matrix, RCA linkage, evidence layer and severity scheme that apply across all 20 Division 13 failure topics.
Every Division 13 failure should ideally be converted into a standard failure record with the following fields:
Asset Identification
Failure Information
Structural Condition
Electrical Condition
Optical Condition
Environmental Condition
RCA
Corrective Action
Verification
Reliability
Division 13 becomes much more valuable when the database captures relationships between failure modes rather than treating each as isolated.
| No. | Failure | Primary Investigation |
|---|---|---|
| 1 | Approach fixture failure | Complete fixture condition |
| 2 | Lamp failure | Lamp/output |
| 3 | LED failure | LED/module condition |
| 4 | Driver failure | Driver input/output |
| 5 | Cable failure | Cable continuity/insulation |
| 6 | Connector failure | Contact/connection |
| 7 | Transformer failure | Transformer electrical condition |
| 8 | Structure damage | Structural integrity |
| 9 | Crossbar damage | Crossbar/support condition |
| 10 | Pole damage | Pole integrity/alignment |
| 11 | Foundation failure | Foundation/civil condition |
| 12 | Frangible-component failure | Frangible component |
| 13 | Misalignment | Fixture/structure alignment |
| 14 | Optical degradation | Optical performance |
| 15 | Moisture ingress | Sealing/enclosure condition |
| 16 | Corrosion | Structural/electrical condition |
| 17 | Circuit failure | Series-circuit condition |
| 18 | Control failure | Control/communication |
| 19 | Multiple approach-light failure | Common-cause investigation |
| 20 | Weather-related damage | Environmental event/damage |
Every approach-lighting failure should eventually become engineering intelligence:
For example: Multiple approach-light failure → Common circuit fault → Cable insulation breakdown → Moisture ingress → Cable replacement → Review sealing/drainage → Post-repair insulation test.
Division 13 links every failure to the Root Cause Analysis Database. The most relevant RCA categories for approach-lighting failures are:
Every failure receives a severity classification, plus operational-impact tagging:
Critical / Safety-Critical — immediate operational or safety risk
Major / Operationally Critical — significant availability impact
Moderate — reduced performance, not yet critical
Minor / Non-Critical — limited or no operational effect
Degradation / Intermittent / Latent — developing or hidden fault
Visual evidence
Technical evidence
The Troubleshooting Atlas answers “I have a fault now — how do I diagnose and fix it?” The Failure Database answers “this failure happened — what happened, why, what evidence proves it, what was done, and how do we stop it recurring?” Kept strictly separate, then linked end-to-end, the two form a genuine AGL Failure Intelligence Engine rather than a simple fault list. Division 13 connects directly with Division 02 Electrical Failures, Division 04 Isolation Transformer Failures, Division 05 Cable & Connector Failures, Division 06 Mechanical & Structural Failures, Division 07 Control System Failures, Division 09 Environmental Failures, Division 18 Maintenance-Induced Failures, Division 19 Product & Component Reliability, Division 21 RCA and Division 23 Reliability Trend Analysis.
Quick answers about approach-lighting failures, as covered in Division 13 of the AGL Failure Database.
Division 13 covers failures in approach-lighting systems. It contains 20 published topics (ALF-01 to ALF-20) spanning fixture, lamp, LED, driver, cable, connector and transformer failures, structural and frangible-component damage, misalignment, optical degradation, moisture, corrosion, circuit and control failures, and weather-related damage.
Approach fixture failure, lamp, LED, driver, cable, connector and transformer failure, structure damage, crossbar damage, pole damage, foundation failure, frangible-component failure, misalignment, optical degradation, moisture ingress, corrosion, circuit failure, control failure, multiple approach-light failure and weather-related damage.
They fall into six groups: Lighting & Component Failures (7 topics), Structural & Mechanical Failures (5), Optical & Alignment Failures (2), Environmental Failures (2), Circuit & Control Failures (2) and System-Level Failures (2).
In the individual-fixture chain, an LED or lamp failure leads to approach fixture failure, an individual approach-light outage and approach-lighting pattern degradation. In the circuit chain, a cable failure leads to circuit failure and multiple approach-light failure.
The diagnostic matrix assigns a primary investigation to each topic. Approach fixture failure starts with complete fixture condition, lamp failure with lamp output, LED failure with LED/module condition, driver failure with driver input and output, cable failure with continuity and insulation, connector failure with contact and connection, transformer failure with transformer electrical condition, and structure damage with structural integrity.
Every failure follows a loop: failure event, failure mode, failure mechanism, root cause, corrective action, preventive action and post-repair test. For example, a multiple approach-light failure is traced to a common circuit fault, then to cable insulation breakdown caused by moisture ingress, leading to cable replacement, a review of sealing and drainage, and a post-repair test.
Every failure receives a severity classification, plus operational-impact tagging. The classes are Critical / Safety-Critical (immediate operational or safety risk), Major / Operationally Critical (significant availability impact), Moderate (reduced performance, not yet critical), Minor / Non-Critical (limited or no operational effect), and Degradation / Intermittent / Latent (a developing or hidden fault).
The Troubleshooting Atlas answers “I have a fault now — how do I diagnose and fix it?” The Failure Database answers “this failure happened — what happened, why, what evidence proves it, what was done, and how do we stop it recurring?” Kept strictly separate, then linked end to end, the two form an AGL Failure Intelligence Engine rather than a simple fault list.
A dark light bar in an ALSF, MALSR or SSALR system can trace back to a lamp, a series-circuit fault, a flasher failure or a CCR issue — real troubleshooting means understanding approach lighting circuit architecture well enough to isolate the actual fault.
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