What does mechanical damage look like?
Cracked lenses, bent housings, sheared bolts, broken frangible parts and cut cables — physical harm from impact, crushing and digging, and often more than meets the eye.
Mechanical damage is physical harm to an asset from impact, crushing, abrasion, vibration or digging, taking it away from its design baseline. It shows as cracked or chipped lenses, bent or crushed housings, sheared or loose bolts, broken frangible parts, cut or crushed cables and displaced fixtures or base cans. Wheel loads, snow-clearing, ground equipment strikes, third-party excavation, pavement movement and poor installation are the usual causes.
What matters is what was hit and what is hidden. A cut or crushed cable or connector can expose conductors, open the loop and let water in later. A frangible part may have broken as designed, but the stub, the fixings and the neighbouring parts still need checking. A fixture that looks sound can have a cracked seal, a stretched cable or a displaced base can, and that often shows up later as moisture ingress or a flicker. Broken pieces are also foreign object debris on the movement area. Do not assume a damaged part is isolated or dead, and look beyond the visible damage.
- Read the symptom. A cracked lens, bent or crushed housing, loose or sheared bolts, a broken frangible part, a cut cable, or a fixture that is displaced, out of level or lit wrongly.
- Make safe and isolate. Work under the permit-to-work; CCR off, locked out and tagged; prove the circuit dead. Mind sharp edges and broken glass; never assume a damaged part is dead.
- Photograph and collect. Photograph as found with date and location, then collect every fragment so none is left as foreign object debris.
- Judge what was hit and how far it goes. A lens or body, a frangible part, a cable or connector, or the base can and mounting? Cosmetic, or is the seal, the circuit or the fixing affected?
- Find the cause. A strike, snow-clearing, excavation, pavement movement or poor installation — fix or report this or it happens again.
- Repair, re-test and record. Critical items first. Replace damaged parts as the manufacturer instructs, check alignment and seals, re-test the circuit and insulation, and log the result.
A frangible part is meant to give way on impact, and light scuffing may not matter. Even so, check what it left behind and replace it as designed. See frangible component.
A cracked seal, cut or crushed cable, displaced fixture or damaged break-away part. Make safe first, then repair or replace and re-test.
Frequently Asked Questions
Q1What is mechanical damage in airfield lighting?
Physical harm to an asset from impact, crushing, abrasion, vibration or digging, taking it away from its design baseline. It shows as cracked or chipped lenses, bent or crushed housings, sheared or loose bolts, broken frangible parts, cut or crushed cables and displaced fixtures or base cans.
Q2What causes mechanical damage to airfield lighting?
Aircraft and vehicle wheel loads, snow-clearing blades and sweepers, ground equipment strikes, third-party excavation, pavement movement or settlement, and poor installation such as over-torquing or a badly seated fixture are the usual causes.
Q3Is a broken frangible part always a fault?
No. A frangible or break-away part is designed to give way on impact. The point is what it did and what it leaves behind: check that it broke where designed, that nothing else was damaged, and that the part and its fixings are replaced as the manufacturer instructs.
Q4Why is damage to a cable or connector treated as critical?
A cut, crushed or pulled cable or connector can expose conductors, break the loop on a series circuit or let in moisture, and the harm may not show on the surface. Critical items are made safe first, and the circuit is isolated and proved dead before anyone touches them.
Q5Why is hidden damage a concern after a strike?
A fixture that looks sound may have a cracked seal, a hairline crack in the body or lens, a stretched cable or a displaced base can. Hidden damage often shows up later as moisture ingress, a flickering lamp or a loose fixture, so a struck unit is inspected and tested, not just checked by eye.
Q6Is it safe to work on mechanically damaged equipment?
Work under the permit-to-work and do not assume a damaged part is isolated or dead. Isolate, lock out and prove the circuit dead before touching any lead or connector, watch for sharp edges and broken glass, and collect all fragments so they do not become foreign object debris on the movement area. Follow the manufacturer's instructions.
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