We work with aerodrome teams across New Zealand to keep runway lighting safe and reliable. Over the years, we’ve seen that water getting into inset luminaires leads to outages, more maintenance, and extra challenges. Too much moisture can dim the lights and light fittings, change their colour, and cause corrosion, all of which lower your facility’s safety margins. Regular audits often find these issues, showing why steady, proactive maintenance is so important.
This guide walks you through a simple way to lower risks, handle maintenance during short night shifts, and keep your records ready for audits. We’ll also show how our team can help with testing, resealing, and keeping your paperwork in shape. By following these steps, you’ll keep your aerodrome lighting safe and reliable.
Why Water Ingress In Inset Light Fittings Matters
When moisture enters the lights or light fittings, it scatters and absorbs the light, making it dimmer and altering its colour. This can make it harder for pilots to see during approach, landing, and taxi. If the lights don’t meet standards, you’ll find more issues during checks. Problems like stuck fasteners, cracked lenses, and stained prisms add to your maintenance workload. More units needing attention means less time for night work and higher costs for emergency replacements. Since ICAO Annex 14 sets clear performance goals, any drop in light quality or outages will be noticed during routine checks.
Root Causes Of Water Ingress
Water always finds the weakest spot, so even small faults can turn into leaks when the system is under pressure. We notice the same issues at many sites: seals lose their stretch, fasteners press gaskets unevenly, and tiny chips in the lens let water in. Over time, cable entries loosen, and tyre spray or rain can push moisture inside. In New Zealand, extra stress comes from salt, frost, and frequent cleaning.
- Seal wear: O-rings flatten with age. Edges nick during removal. Hardening from heat or fuel exposure reduces rebound.
- Gasket issues: Uneven torque pinches the gasket on one side and lifts it on another. Dirt in grooves stops full seating.
- Lens damage: FOD and mower strike create micro cracks. Thermal shock during cold nights worsens small chips.
- Cable entries: Glands lose compression. Grommets crack from UV and fuel. Loose locknuts allow movement and wicking.
- Conduits and pits: Poor joints pull water by capillary action after heavy rain. Cracked pits feed cans during ponding.
- Environment: Coastal salt attacks metals and elastomers. Frost cycles open gaps. Night washdowns push water past weak seals.
- Installation habits: Dry assembly of seals. Mixed lubricants across elastomer types. Reused O-rings after lifts. Missing cross-tightening pattern.
Which IP Ratings Matter for Light Fittings?
The IP rating (IEC 60529) tells you how well a fitting keeps out dust and water. Each digit shows the level of protection against solids and liquids. When picking and installing lights and light fittings, consider where they’ll be used. For exposed runway light fittings, choose ones that are dust-tight and water-resistant to avoid problems during heavy rain or cleaning. If the second digit is low, check those units more often, especially where water can collect. Always review the manufacturer’s test details, since IP ratings come from lab tests. Good seals and proper torque are still essential.
How NZ Rules And Global Guidance Shape Maintenance
CAA Part 139 sets expectations for safe operation and record keeping at New Zealand aerodromes. ICAO Annex 14 defines performance aims for visual aids used for guidance and visibility. Local procedures then translate those aims into inspection intervals, acceptance tests, and remedial work orders. Maintenance records need to link findings, actions, and results to the relevant rule parts. Consistency supports compliance and speeds audits.
Monthly Visual Checks For Inset Units
Scope: Run short, regular checks to catch early signs before water enters the chamber.
Steps
- Walk the line during low-traffic periods.
- Look for lens haze, chips, or spider cracks.
- Check for condensation or fogging inside the optic.
- Confirm gasket seating along the visible edge.
- Verify no debris or rubber build-up on the bezel.
- Log serials, defects, and actions in the register.
Notes
Small issues escalate under heavy rain. Early action preserves availability between quarterly services.
Quarterly Seal And O-Ring Inspection
Preparation
- Isolate the circuit at the CCR.
- Tag and test for dead.
- Gather OEM O-rings, gaskets, lubricant, and a calibrated torque driver.
Inspection
- Lift the unit using the proper puller.
- Remove the ring and lens per manual.
- Inspect O-rings for flat spots, nicks, swelling, or age hardening.
- Clean grooves with lint-free wipes.
- Check lens seating surfaces for scratches or burrs.
- Replace seals that fail inspection.
- Apply the approved lubricant in a thin film.
- Reassemble following the torque sequence.
- Record parts, torque, and inspector initials.
Moisture Removal, Desiccant Use, And Re-Seal Triggers
If you notice fogging but no pooled water, you can usually fix it by drying the unit in a warm, dry place as described in the manual. Add new desiccant pouches if needed. If the fogging returns soon, it probably means a seal has failed or there’s a small crack. In that case, do a full reseal, check the lens, and run a pressure test. Keep a record of how often this happens so you can plan replacements before bigger issues develop.
Photometric Consequences Of Moisture
Water films change the refractive path across prisms and lenses. Output intensity falls and the colour point shifts. Expect out-of-tolerance readings during maintenance checks. Each outlier raises the chance of findings during verification. Annex 14 sets the aims for intensity and distribution, so moisture intrusion directly threatens compliance. A sample photometric check after reseal reduces risk before a full programme run.
Documentation That Proves Compliance
Auditors look for traceable records. Provide the work order reference, technician names, training currency, and PPE used. List parts with batch numbers. Include torque values and driver serials. Attach pressure test results and photometric spot checks with timestamps. Add before and after photos. Cross-reference the aerodrome procedure and CAA Part 139. Store the file under the asset’s serial number for fast retrieval.
When To Bring In Specialists
Some faults are found in the can, flange, or cable assembly. If pressure tests keep failing, the seating surfaces may be deformed. If fogging comes back quickly, there could be hairline cracks or the wrong lubricant. If several lights show photometric drift, it may be a bigger issue. When this happens, it’s time to call in specialists. We offer bench testing, leak mapping, OEM-grade seals, and light refitting services. We also provide acceptance tests and an audit-ready pack with clear records.
LED Upgrades And Moisture Risk
LED engines reduce relamping frequency and improve energy performance. Moisture still harms drivers and optics. Older cans often have worn flanges and outdated glands, which raises risk after retrofit. Plan a seal refresh and pressure test before and after installation. Confirm chromaticity and intensity with a sample photometric check. Follow the fixture manual and site procedures for acceptance criteria.
A Simple Monthly And Quarterly Checklist
Monthly actions
- Line walk for lens damage, haze, or cracks.
- Check for internal condensation.
- Wipe bezels and remove rubber build-up.
- Glance at gasket seating and fastener status.
- Inspect cable entries for abrasion or perishing.
- Update the asset log with defects and tasks.
Quarterly actions
- Isolation and lift.
- O-ring inspection and replacement as required.
- Groove clean and lens inspection.
- Lubricant applied per OEM.
- Torque in a star pattern to value.
- Pressure test with dwell.
- Sample photometric check.
- Record pack with parts and test results.
Field Test Envelope And Tooling
Safe test practice relies on correct tooling. Use a pressure rig with a certified gauge. Fit the correct caps and adapters. Keep a spare set of O-rings and gaskets on hand to avoid partial reassembly. Carry lint-free wipes, lens-safe cleaners, and a low-lint swab kit. Maintain a torque driver calibration schedule. Record calibration dates in the equipment register. Keep a labelled kit for each fixture family to avoid part mix-ups.
Common Pitfalls And How To Avoid Them
- Reusing old O-rings after a lift. Always install fresh seals.
- Mixing lubricants across elastomer types. Stick to the approved product.
- Over-torque during reassembly. Follow the manual.
- Skipping pressure tests after reseal. Verify integrity before return to service.
- Ignoring cable entry wear. Replace glands and grommets before they leak.
- Poor record keeping. Without traceability, audits slow down and issues repeat.
- Using non-OEM seal kits. Tolerances drift and leak risk rises.
- Cleaning lenses with harsh solvents. Surface crazing increases moisture traps.
- Leaving debris in grooves. Particles create micro paths for water.
When Should You Get Professional Airfield Lighting
We help with inspections, reseal programs, pressure testing, LED retrofit checks, and full documentation packs. We work at aerodromes across New Zealand and follow site procedures and CAA Part 139 rules. We also give advice on seal materials, torque tool setup, and record templates. Our aim is safe, reliable airfield lighting with fewer night outages and a clear audit trail. We know runway closures are tight, so we plan work in short windows and return units to service quickly and confidently.
Audit-Ready Moisture Control For Inset Units
Controlling water ingress starts with a practical routine. Short monthly checks help catch small issues early. Quarterly reseals boost reliability before rain and cold weather set in. IP ratings are helpful, but good practice matters more. Careful O-ring checks, proper torque, and regular pressure tests keep the system tight. Good records then help you meet CAA Part 139 and ICAO Annex 14 requirements.
We use reliable test equipment, original parts, and keep records that meet audit needs. Our teams work across New Zealand and know the challenges at busy aerodromes. We plan our work to fit your schedule, help prevent repeat problems, and provide clear paperwork. If you need help with seals, LED upgrades, or leak checks, just let us know. We’re here to help you keep your light fittings safe, compliant, and running smoothly.
