What is repair?
Bringing a failed asset back to working order — made safe, diagnosed, fixed, proved by test and recorded.
Repair is the corrective work that restores a failed asset to its required function. It starts with the permit and airfield clearance, then makes the area safe and isolates the circuit, then diagnosing the fault so the right part is fixed rather than just the symptom.
The work is prepared with spares, tools and an agreed method, carried out, and then proved by testing before the asset is returned to service. The repair is recorded so the asset history is complete. A poor repair means repeat faults, hidden defects and an unsafe return to service.
- Isolate. Make the area safe, isolate the circuit, and lock out and tag it under the permit to work.
- Diagnose. Locate the fault with tests and inspection, and confirm its cause.
- Prepare. Have the spares, tools, permit, airfield clearance and method agreed before work starts.
- Fix. Repair the part, re-terminate or re-seal it, or replace the failed component.
- Test. Check continuity and insulation resistance, light or sign operation, and status at the monitoring system.
- Return. Return the asset to service, inform operations and record the repair.
Restores the existing asset or part to working order, for example a re-made connector, a repaired joint or a replaced lamp.
Renews the whole asset at the end of its useful life or when repair no longer makes sense (a later lifecycle entry).
Frequently Asked Questions
Q1What is repair in airfield ground lighting?
Restoring a failed or faulty AGL asset to a condition where it performs its required function again, for example re-terminating a connector, replacing a failed lamp or LED module, repairing a cable joint or re-sealing a fixture. Repair follows failure in the asset lifecycle.
Q2How is repair different from preventive maintenance?
Preventive maintenance is planned work done before a failure to reduce its likelihood. Repair is corrective work done after a fault has appeared, to bring the asset back into service. Both are part of the maintenance programme, and repair findings often feed back into preventive tasks.
Q3Why make the circuit safe and isolate it before repair?
AGL circuits are usually series circuits fed from a constant current regulator at high voltage, so working on a live circuit is dangerous. The circuit is switched off, isolated at the CCR, locked and tagged under a permit to work, and proved dead and earthed where required, before anyone opens a fixture, connector or cable. A live series circuit must never be opened, and long cable runs can hold charge, so the circuit is discharged after insulation-resistance testing.
Q4What is tested after a repair?
Typical checks are continuity and insulation resistance of the repaired part of the circuit, compared with the earlier test records, correct operation of the light or sign, and clear status at the control and monitoring system. Light output and alignment are checked where the repair could have affected them. Test values and acceptance criteria come from the manufacturer and the aerodrome procedures.
Q5When is repair not the right answer?
When the cost, risk or repeat-failure rate of repairing is worse than renewing, or when parts are no longer available, the asset is considered for refurbishment or replacement instead. Repair records provide the evidence for that decision.
Q6What should be recorded after a repair?
The fault found, the cause if known, the work done, parts used, tests and results, who did it, when service was restored and how long the lighting was affected. These records update the asset history and support root-cause review, spares planning and asset planning.
See It. Understand It. Then Learn How to Engineer It.
Recognising an AGL system visually is the first step. The next step is knowing how to design, install, test, commission and maintain them correctly.
Build Practical AGL Engineering Skills
Go deeper with structured training from Precision AGL Academy, covering:
Learn how each light, sign and circuit works as part of a complete airport lighting system, not just as an isolated diagram.