The operational-event and service-impact section of the AGL Failure Database. Unlike Divisions 01–09, Division 10 focuses on the operational incident itself and its effect on airport/AGL availability — rather than only the underlying component failure. The same event can therefore carry cross-references to multiple technical divisions.
Key principle — Division 10 does not replace Divisions 01–09; it sits as the operational-event layer above them. For example: LED driver failure → Division 01, circuit open circuit → Division 02, CCR shutdown → Division 03, vehicle impact damage → Division 06/09 as applicable — but the resulting runway light outage is recorded here as the Division 10 operational incident, retaining every level of the chain from component to airport impact.
Loss of required runway lighting service affecting one or more runway lighting functions.
Determine: what lights are affected → how many → location → circuit → CCR → control status → electrical condition.
Severity depends on the lighting function affected, number of affected fixtures, location, time of occurrence, operational conditions and redundancy available.
Loss of required taxiway lighting service.
Identify the affected taxiway section and determine whether the outage is single fixture, local group, circuit-wide, multiple circuit, or system-wide.
Failure of two or more AGL lighting circuits or associated circuits during the same incident or related event.
Look specifically for the common cause — for example: common power failure → multiple CCRs unavailable → multiple circuits fail.
Multiple-circuit failures deserve higher-level RCA because they may expose a common-mode vulnerability.
Loss of electrical power required for AGL operation.
Trace the power path: source → distribution → protection → CCR/control equipment → series circuit → fixture.
AGL equipment shuts down without an intended operational command or planned maintenance action.
Establish whether the shutdown was commanded, automatic, protective, or unexplained. This distinction is essential.
Recurring alarm conditions indicating repeated or unresolved abnormal system behaviour.
Do not treat each alarm as an independent event initially. Look for frequency, timing, common equipment, common circuit, environmental correlation and maintenance history.
Repeated alarm → unresolved condition → eventual operational incident can be an important leading indicator.
Damage or disruption to AGL equipment caused by wildlife activity.
Record wildlife evidence, location, affected equipment, physical damage, previous occurrences, and environmental conditions.
Wildlife damage should be recorded as the incident cause, while the actual technical damage can be cross-referenced to the relevant failure division.
An operational incident involving vehicle contact with AGL equipment or associated infrastructure.
Perform a complete impact assessment: fixture, frangible component, base can, mounting, foundation, cable, connector, alignment, and surrounding pavement/civil condition.
Division 06 — Mechanical & Structural Failures and, where applicable, Division 05 — Cable & Connector Failures.
Damage or operational disturbance resulting from a foreign object affecting AGL equipment or the airfield environment.
Determine: object → source → impact location → damaged asset → operational consequence.
Damage or disruption caused by construction, civil works, excavation, equipment movement or related activity.
Review construction activity, work permit, work area, drawings, utility/AGL information, and protection/isolation arrangements.
AGL equipment or circuit is unintentionally isolated from service.
Verify: equipment intended to remain available → actual isolation → person/system performing isolation → authorization → switching record.
Incorrect switching action causes an unintended change in AGL system operating condition.
Review switching instruction, switching sequence, operator action, control indication, equipment response, and switching record.
Intentional or automatic shutdown of equipment/system in response to an emergency condition.
An emergency shutdown is not necessarily a failure. It becomes an operational incident when it results in unexpected loss of service, unplanned operational impact, emergency intervention, or significant AGL unavailability.
Determine whether the shutdown was necessary and correct or unnecessary/incorrectly triggered.
Loss of lighting identified as operationally critical to the affected airport movement area or procedure.
Record critical lighting function, number of affected units, location, duration, redundancy available, operational effect, and actions taken.
This category should be linked to operational criticality, not merely the number of failed fixtures.
Loss of part of an AGL system while the remaining system continues operating.
Determine: affected portion / unaffected portion / redundancy / operational impact.
Complete loss of service of the affected AGL system.
This should trigger high-priority RCA and incident review.
AGL service repeatedly becomes unavailable and subsequently returns without a stable permanent correction.
Capture start/end time, frequency, duration, conditions, equipment state, alarm history, and environmental correlation.
Intermittent failures can be particularly difficult because the equipment may appear normal during inspection.
An AGL incident results in a measurable disruption to normal airport operations.
Airport operational disruption is an outcome, not necessarily the root failure. Example chain: CCR failure → runway circuit outage → loss of critical lighting → runway operational restriction → airport operational disruption. The database should retain every level of that chain.
Standard record structure, severity classification, incident chains, and cross-division linkage that apply across all 18 Division 10 operational incident topics.
Every Division 10 incident should capture the following fields, grouped across identification, classification, operational condition, investigation, response and reliability:
Division 10 distinguishes equipment failure severity from operational consequence severity via a five-level scale:
Level 1 — Localized: single fixture or small localized incident (e.g. single taxiway edge light outage)
Level 2 — Limited: multiple fixtures or localized circuit/service impact (e.g. one taxiway lighting circuit unavailable)
Level 3 — Significant: major portion of a lighting system affected (e.g. multiple runway lighting circuits unavailable)
Level 4 — Critical: loss of critical lighting or major AGL capability (e.g. critical runway lighting unavailable)
Level 5 — Airport Operational Disruption: significant airport operational restriction or disruption
The same operational event can carry cross-references to any of the technical failure divisions, depending on the underlying component or cause:
Division 10 retains every level of a chain rather than collapsing it to a single record. Five representative chains:
Chain 1 — Runway
Chain 2 — Power
Chain 3 — Vehicle
Chain 4 — Human Operational Error
Chain 5 — Intermittent Failure
Division 10 should not replace Divisions 01–09 — it acts as the operational-event layer above them. A single failure escalates through seven recognisable levels:
Divisions 01–09 answer “what component failed, and why?” Division 10 answers “what did that failure do to lighting service and airport availability?” The recommended database architecture strings both together: Operational Event → Affected AGL Asset → Technical Failure → System Failure → Lighting Service Impact → Operational Severity → Airport Impact → Immediate Response → Root Cause → Corrective Action → Verification → Recurrence/MTTR → Lessons Learned — making Division 10 the bridge between the technical failure divisions and the higher-level maintenance, emergency response, audit, reliability and continuous-improvement divisions.
Quick answers about operational incidents and airport-level impact, as covered in Division 10 of the AGL Failure Database.
Division 10 is the operational-event layer above Divisions 01–09. It contains 18 published topics (OPI-01 to OPI-18) covering lighting outages, power and equipment incidents, external and accidental damage, operational control incidents, system availability incidents and airport operational disruption.
Runway light outage, taxiway light outage, multiple circuit failure, power loss, unexpected equipment shutdown, repeated alarm events, wildlife damage, vehicle impact, foreign-object damage, construction-related damage, accidental equipment isolation, operational switching error, emergency shutdown, loss of critical lighting, partial, complete and intermittent system outage, and airport operational disruption.
They fall into six groups: Lighting Outage Incidents (3 topics), Power & Equipment Incidents (3), External & Accidental Incidents (4), Operational Control Incidents (3), System Availability Incidents (4) and Airport-Level Impact (1).
Division 10 distinguishes equipment failure severity from operational consequence severity using a five-level scale: Level 1 Localized (a single fixture), Level 2 Limited (for example one taxiway lighting circuit unavailable), Level 3 Significant (a major portion of a lighting system affected), Level 4 Critical (loss of critical lighting or major AGL capability) and Level 5 Airport Operational Disruption.
Divisions 01–09 answer what component failed and why. Division 10 answers what that failure did to lighting service and airport availability. Division 10 does not replace the technical divisions; the same operational event can be cross-referenced to any of them depending on the underlying component or cause.
Division 10 retains every level of a chain rather than collapsing it into one record. In one runway chain, a CCR failure leads to a runway circuit outage, runway light outage, loss of critical lighting, operational restriction and airport operational disruption. The five representative chains also cover power loss, vehicle impact, operational switching error and intermittent failure.
A single failure escalates through seven recognisable levels, from the technical component through component failure, electrical consequence, lighting consequence, system consequence and operational consequence to airport consequence. For example, an LED driver failure can cause an open circuit, then a runway light outage and a partial runway lighting outage.
Each incident record captures identification (incident ID, airport/project, date/time, location, affected runway, taxiway or area), the affected system, asset or circuit, incident category and type, failure mode, operational severity and criticality, investigation results, response and reliability information.
An operational incident touches more than the failed component — it touches CAT I/II/III availability, ATC coordination and runway operations — real troubleshooting means understanding that wider picture well enough to prevent a repeat.
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