If you run a certified aerodrome in Australia, your runway markings are not a matter of preference. They are set out in the Part 139 Manual of Standards, and an aerodrome inspection will pick up markings that have faded, been laid out incorrectly or worn back past the point of being clearly visible.
This article covers what MOS 139 aerodrome standards mean in practice for runway markings, which markings your runway needs, and how to tell when it is time to book a re-mark.
What MOS 139 aerodrome standards actually are
MOS 139 is the Manual of Standards that sits under Part 139 of the Civil Aviation Safety Regulations. It is published by CASA and it sets the design and operational standards for certified aerodromes, including the visual aids that pilots rely on.
Runway markings sit squarely inside those visual aids. They tell a pilot where the runway begins, where the centreline runs, where to aim on approach and where the touchdown zone sits. They also align with ICAO Annex 14, which is why an Australian runway looks familiar to a pilot who trained overseas.
For most operators the practical takeaway is simple. The markings are not decoration. They are a safety system, and they are inspected.
Which runway markings MOS 139 aerodrome standards cover
Which markings apply depends on the runway and the type of approach it serves. The common ones are:
- Runway designation markings. The two digit number at each end, taken from the magnetic bearing, plus L, C or R where there are parallel runways.
- Runway centreline markings. The dashed line down the middle, in a uniform pattern of stripes and gaps.
- Threshold markings. The set of longitudinal stripes at the runway start, the ones most people picture when they think of a runway.
- Aiming point markings. The two broad rectangles further down, giving the pilot a visual aiming target.
- Touchdown zone markings. Paired rectangles at set intervals, used on precision approach runways.
- Runway side stripe markings. The continuous lines down each edge that define the usable width, which matter most where the pavement and shoulder are similar in colour.
- Holding position markings. Where taxiways meet the runway, keeping aircraft clear of the strip.
Not every runway carries all of these. A regional or remote airstrip serving daytime operations will have a different set to a precision approach runway at a capital city airport. The standard is what determines it, not what was there last time.
Where operators most often come unstuck
In our experience the problems are rarely exotic. They are usually one of four things.
Faded markings that still technically exist. A marking that has worn back to a grey outline is not doing its job. It reads fine from a ute at walking pace and poorly from an aircraft on approach.
Markings that were never quite right. An overlay goes down, the markings get reinstated from memory or from photographs, and the geometry drifts. Dimensions and spacing are specified for a reason.
Rubber build up in the touchdown zone. Deposits from tyres obscure exactly the markings that matter most on landing. Removal is a specialist job, not something to grind away at.
Nothing scheduled. Marking gets treated as a reactive task and only comes up when an inspection flags it, which is the most expensive time to deal with it.
How to tell when it is time for a re-mark
There is no single interval that suits every aerodrome. Wear depends on traffic, pavement type, climate and how much of the year the surface spends in direct sun. Northern Australia is harder on paint than the southern states.
A practical approach is to look at three things:
- Contrast. Can you clearly distinguish the marking from the pavement in bright midday light, not just at dawn?
- Edges. Are the edges of the stripes still crisp, or have they feathered and broken up?
- Coverage. Is the paint film continuous, or is the surface showing through across large sections?
If any of those are marginal, book the work before your next inspection rather than after it. Re-marking a runway that is still in reasonable condition is faster and cheaper than reinstating markings that have disappeared entirely.
Getting the work done at a live aerodrome
Marking a runway is not only a painting job. It is a job carried out on an operational movement area, often with traffic still running.
That is why our linemarkers hold RED ASIC cards for airport access, and why our team includes CASA certified air and ground radio operators. Working airside means being able to communicate properly, understand a clearance and get off the runway when required. We also carry 20 million dollar public liability insurance.
We use Wattyl paints across all our line marking, tested to meet the harsh requirements of Australia and New Zealand’s environment. On a runway in far north Queensland that matters more than it does on a suburban carpark.
Working with regional and remote aerodromes
Over 25 years we have marked runways at regional, mining and remote airports including Aurukun, Lockhart River, Normanton, Mundubbera, Karumba, Mt Isa, Emerald, Port Augusta, Connellan at Uluru and Parkes, as well as major overlay projects in Brisbane, Sydney and Melbourne. We have also worked in Papua New Guinea.
Remote work brings its own constraints. Access windows are short, mobilisation is expensive and there is rarely a second chance to come back next week. Planning the job properly matters as much as the marking itself.
Getting your runway markings sorted
If your markings are fading, your aerodrome has an inspection coming, or you have an overlay scheduled and need the markings reinstated afterwards, we can help.
Take a look at our line marking services or get in touch with Shane and Mel for a free quote.
