What is the preventive maintenance sequence?
The planned order of work on a scheduled visit — plan and permit, look while live, isolate, clean, inspect and test, then restore, verify and record, so wear is found and fixed before a light fails.
Preventive maintenance is work done on a schedule to find wear before a light fails. The sequence matters: the visit is planned and permitted, begins with a look while the circuit is live, then moves to hands-on work under one isolation — cleaning, inspecting, tightening, replacing worn parts and testing — and ends with the circuit restored, the lights verified and the results recorded.
Doing the steps out of order costs time or safety: isolating before looking can mean an outage for a problem that needed none, and re-energising before testing can put a fault straight back on the circuit. Hands-on work starts only when the circuit is isolated, locked out and proved dead, under the airport’s permit-to-work. The records, readings and recurring defects from each visit are what show a trend and shape the next plan.
- Plan. Work from the maintenance programme: permit, parts, tools, and agreed access and outage with airport operations.
- Look. With the circuit live, walk the lights and signs and note what is out, dim, dirty or damaged.
- Isolate. Switch off, lock out and prove the circuit dead before any hands-on work.
- Service. Clean, inspect, tighten and replace worn parts, grouped under the one isolation.
- Test. Check insulation, continuity and earthing before the circuit is re-energised.
- Restore & record. Re-energise, verify the lights, then log the work and trend the readings.
Frequently Asked Questions
Q1What is the preventive maintenance sequence in airfield ground lighting?
It is the planned order of work carried out on a schedule to find and fix wear before lights fail. A typical visit is planned and permitted, starts with a visual check while the circuit is live, then isolates the circuit for cleaning, inspection, tightening and testing, and ends by restoring, verifying and recording the results.
Q2Why look at the lights before isolating the circuit?
Some defects only show while the lights are on, such as lamps out, uneven brightness or a pattern of failures that points to a circuit fault. Looking first records the installation as it is, and it avoids an outage for a problem that needs no isolation. Hands-on work then starts only once the circuit is isolated, locked out and proved dead.
Q3Why group tasks under one isolation?
Every isolation takes a circuit out of service and needs switching, locking out and proving dead. Grouping cleaning, inspection, tightening and testing under one isolation keeps the outage short and the number of switching operations low. The order of tasks inside it still follows the plan and the permit-to-work.
Q4How often should preventive tasks be done?
The intervals come from the airport's maintenance programme, the regulator's requirements and the manufacturers' instructions, and they differ by task and by how critical or worn an area is. Quick visual checks are the most frequent, cleaning and inspection less often, and electrical and earthing tests at longer intervals.
Q5Why test after servicing and before restoring the circuit?
Cleaning, replacing parts and opening enclosures can disturb connections and seals. Insulation, continuity and earthing checks prove the circuit is sound before it is re-energised. After restoration the lights are checked on and any intensity steps are verified, so the circuit is handed back in a known good state.
Q6How is preventive maintenance different from corrective maintenance?
Preventive maintenance is planned and scheduled, and it works on wear and condition before anything fails. Corrective maintenance responds to a fault that has already happened. The records from preventive visits, such as readings and recurring defects, show trends that help plan the next visit and reduce corrective calls.
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