What is structural deterioration?
Base cans, masts, frames, foundations and pits that are slowly losing strength, shape or position — cracking, corroding, bending and settling — and how an inspector decides how far it has gone.
Structural deterioration means the parts that hold the lighting in place are losing strength, shape or position over time. A base can cracks, tilts or sinks, a mast or sign frame bends or corrodes, a foundation or grout joint breaks up, a frangible point is damaged, and a pit lid is crushed or sunk.
Structural deterioration is a change in the part itself, not a mark on it, so cleaning or tightening does not put it right. A slight change with the part still sound and in position is recorded and monitored. A growing or widening crack, loss of metal, loose fixings, a slight tilt, or any change beyond the manufacturer’s or design limits is repaired and re-checked. A broken support, a damaged frangible point, a leaning structure or a can or lid standing proud of the pavement is critical: it is reported and made safe first, because aircraft and vehicles pass close by and a frangible fitting may no longer break away as designed. A tilted, sunk or turned fixture can also be mis-aimed, so its beam no longer meets the photometric requirement even though the lamp works.
A change in the strength, shape or position of the support itself: cracks, lost metal, bending, settlement or movement. It is repaired or replaced, often to the original design.
Scuffed paint, dirt or light surface rust on a part that is still sound and in position. It is cleaned, treated and monitored.
- Make the area safe. Work under the permit-to-work and airside rules, isolate where the procedure requires it, and take care at height and near traffic.
- Record as found. Photographs with date and location, and mark crack ends so any growth can be seen next cycle.
- Inspect the structure. Cracks, corrosion, bending, movement, settlement, loose or missing fixings, damaged frangible points.
- Check position and height. Level, upright and flush with the pavement, measured by the method in the procedure rather than by eye alone.
- Look for the cause. Water or poor drainage, impact, frost, de-icing chemicals, settlement or jet blast, so the repair does not fail the same way.
- Classify and act. Minor, major or critical, then record, repair and re-check, or report and make safe. Do not pack, shim or re-grout over a cracked or damaged support to hide movement. Repair or replace it to the design, with like-for-like frangible parts.
Frequently Asked Questions
Q1What does structural deterioration mean in AGL inspection?
A gradual loss of strength, shape or position in the parts that hold the lighting in place, such as base cans, fixture bodies and masts, sign frames, foundations, and pits and covers. It shows as cracking, corrosion, bending, settlement, loose fixings or crushed lids. It is recorded, classified by how far it has gone and what it endangers, and acted on according to the site's procedures.
Q2How is structural deterioration different from surface wear?
Surface wear is cosmetic: scuffed paint, dirt or light surface rust with the part still sound. It is cleaned, treated and monitored. Structural deterioration is a change in the strength, shape or position of the part itself, so cleaning or tightening does not put it right and the part is repaired or replaced, often to the original design.
Q3What causes structures to deteriorate?
Age, corrosion, wheel loads, impact from vehicles and equipment (including snow-clearing), frost, de-icing chemicals, ground settlement, jet blast, and water from poor drainage or failed seals. Finding the cause matters, or the repaired part fails the same way.
Q4What does structural deterioration look like?
Cracked or spalled concrete and grout, a base can that has moved, tilted or sunk, a corroded or pitted flange, a bent or leaning mast, a damaged frangible point, a cracked sign housing or bent frame, corroded or missing fasteners, and a broken or sunken pit lid. A support can look sound from above and still be weakened underneath.
Q5How is structural deterioration classified?
By how far it has gone and what it endangers. Minor means a slight change with the part still sound and in position, which is recorded and monitored. Major means a growing or widening crack, loss of metal, loose fixings or a slight tilt, or any change beyond the limits set by the manufacturer or design, so the part is repaired or replaced and re-checked. Critical means a broken support, a damaged frangible point, a leaning structure or a can or lid standing proud of or below the pavement, which is reported and made safe first.
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