What is the corrective maintenance sequence?
The order of work after a fault — report and assess, locate while live, isolate and prove dead, repair, test, then restore, verify and record the cause, so the fault is fixed and does not come back.
Corrective maintenance is work done after a fault has happened. The sequence matters: the fault is reported and assessed first, then located while the circuit is live where that is safe, then repaired under one isolation, tested, and only then restored, verified and recorded — including what caused it.
Unlike a planned visit, the starting point is a report or alarm and the priority is set by how the fault affects aircraft operations, so the response is agreed with airport operations before an outage is taken. Hands-on work starts only when the circuit is isolated, locked out and proved dead, under the airport’s permit-to-work. Testing comes before re-energising, so a remaining fault is not put straight back on the circuit. Recording the cause turns a one-off repair into information the preventive programme can use.
- Report. Record how the fault was found — a CCR or ALCMS alarm, a patrol finding or a call — with the circuit, location and time.
- Assess. Decide which lights are affected and how urgent it is for the runway or taxiway in use, and agree access and outage with airport operations.
- Locate. With the circuit live where safe, use alarms, indications and a visual check of the lights, without opening pits or touching leads, to narrow down the fault before any outage.
- Isolate. Switch the CCR off, take it out of remote and ALCMS control, lock out and prove the circuit dead under the permit, then earth or discharge it as the procedure requires. Split the loop at pits or connectors and test each part to find the fault.
- Repair & test. Repair or replace like for like, then check insulation, continuity and earthing before re-energising, discharging the circuit after any insulation test.
- Restore & record. Close the permit, re-energise, verify the lights, then log the fault, cause, parts and readings.
Frequently Asked Questions
Q1What is the corrective maintenance sequence in airfield ground lighting?
It is the order of work after something has gone wrong: the fault is reported and assessed, located while the circuit is live where that is safe, then isolated and proved dead for the repair. The repair is tested, the circuit is restored, the lights are verified and the cause is recorded.
Q2How does corrective maintenance differ from preventive maintenance?
Preventive maintenance is planned in advance to find wear before a light fails. Corrective maintenance responds to a fault that has already happened, so the visit starts from a report or alarm, is prioritised by how much the fault affects aircraft operations, and ends by finding the cause as well as fixing the symptom.
Q3Why assess the fault before isolating the circuit?
A fault is not always equally urgent. Assessing which lights are affected, and what that means for the runway or taxiway in use, decides how quickly to act and what to agree with airport operations. Alarms and indications on a live circuit also help locate the fault before any outage is taken.
Q4How is a fault located on a series circuit?
Where indications and a visual check do not find it, the isolated loop is split at convenient points, such as transformer pits or connectors, and each part is tested. The faulty part is then split again until the fault is narrowed to one cable length, connector or transformer.
Q5Can the circuit be re-energised to see whether the repair worked?
Not before testing. Insulation, continuity and earthing are checked on the repaired circuit while it is still isolated, so a remaining fault is not put straight back on the circuit. The circuit is only restored once the permit is closed and the tests are satisfactory.
Q6Why record the cause of a corrective job?
Replacing the failed part clears the symptom, but the record of what failed, where and why shows repeat problems such as moisture in a pit or a worn connector type. That history feeds the preventive programme and reduces the same fault returning.
Q7What response times and test values apply to corrective work?
They depend on the airport's maintenance programme, the regulator, the equipment manufacturers' instructions and the applicable standard, so this page gives no fixed figures. Always follow your site's permit-to-work procedure.
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