One aircraft holding short. One clearance not yet spoken. One painted line on the tarmac. Runway incursions remain one of European aviation's most stubborn safety risks, which is why preventing them sits near the top of EASA's European Plan for Aviation Safety (EPAS) for 2026.
For the ATPL theory candidate, aerodrome markings and signs look deceptively simple. They are not. They are examinable in 010 Air Law and 070 Operational Procedures, and they are exactly the kind of detail the ECQB tests with a single well-chosen distractor.
Here are seven traps that catch EASA ATPL students, and the correct principle behind each.
1. Reading the runway number as a heading
The two digits painted on the threshold are not the runway's heading. They are the magnetic bearing of the centre line, rounded to the nearest ten degrees, then divided by ten.
So RWY 09 points roughly 090 degrees magnetic, but the true centre line could lie anywhere from about 085 to 094. The reciprocal end differs by 18 (09/27, 18/36). Parallel runways add L, C or R. And because magnetic variation drifts over the years, aerodromes occasionally renumber a runway, so watch for questions that quote a new designator.
2. Treating threshold "piano keys" as decoration
The longitudinal white stripes at the threshold, the "piano keys", mark where the runway available for landing begins. The number of stripes is not random: it is coded to runway width (illustratively, eight stripes for a 30 m runway and twelve for 45 m). Miss that and you miss an easy identification mark.
3. Confusing a displaced threshold with unusable pavement
White arrows running along the centre line toward a solid transverse bar mean a displaced threshold. The paved area before it is still usable: for take-off, for roll-out after landing from the opposite direction, and for taxiing. You simply may not touch down on it.
Contrast that with a blast pad or stopway, marked with yellow chevrons. That surface is not for taxi, take-off or landing at all. Swapping these two is a classic exam error.
4. Aiming for the touchdown zone at the aiming point
The two large rectangular blocks a few hundred metres in are the aiming point, the visual target for your approach path, where the PAPI and glidepath are set. On airline-length runways they sit roughly 300 m (about 1,000 ft) from the threshold, though the exact distance is coded to the landing distance available.
You do not touch down on the aiming point. Touchdown happens in the touchdown zone, the coded pairs of bars straddling it, usually a little before. Keep the two terms distinct.
5. Crossing a runway-holding position marking that "looks clear"
This is the big one. The runway-holding position marking is two solid and two dashed yellow lines. You hold at the solid side. You do not cross onto the runway side without an explicit ATC clearance, no matter how empty the runway looks.
The "ladder" Pattern B marking protects the runway during low-visibility (CAT II and CAT III) operations. This single marking is the front line against runway incursions, which is why EASA keeps sharpening the standard in its aerodrome design specification, CS-ADR-DSN.
6. Letting the coloured signs blur together
Sign colour tells you the sign's job. Learn the three you cannot afford to confuse:
- Red background, white text: mandatory instruction (runway designation, NO ENTRY, CAT II/III holding). You may not pass without clearance.
- Yellow background, black text: direction or destination, always with an arrow. Where you are going.
- Black background, yellow text: location. Where you are right now, such as taxiway "B".
A quick memory hook: red stops you, black tells you where you are, yellow points where to go.
7. Ignoring enhanced centrelines and edge markings
The enhanced taxiway centre line, dashed yellow lines flanking the solid centre line, is a deliberate warning that a runway-holding position is ahead. Slow down and expect to hold.
Taxiway edge markings matter too: a continuous double yellow line means do not cross, while a dashed double line marks a shoulder you may cross. None of it is cosmetic. It is all part of EASA's standardisation to cut incursions.
Where this shows up in the exams
Expect these markings in Air Law (aerodromes, built on ICAO Annex 14 and transposed through EASA's Part-ADR and CS-ADR-DSN) and in Operational Procedures. The questions are rarely hard. They reward candidates who have actually pictured the markings rather than skim-read them. Draw them once, label every element, and they stick.
Frequently asked questions
What does the runway number actually mean?
It is the magnetic bearing of the runway centre line, rounded to the nearest ten degrees and divided by ten. RWY 27 points about 270 degrees magnetic, and its reciprocal is RWY 09.
Can you take off before a displaced threshold?
Yes. The area before a displaced threshold may be used for take-off, for landing roll-out from the opposite direction, and for taxiing, but not for landing touchdown. A blast pad marked with chevrons, by contrast, cannot be used at all.
What do two solid and two dashed yellow lines mean?
That is a runway-holding position marking. Hold at the solid side and cross onto the runway side only with an explicit ATC clearance. It is the primary defence against runway incursions.
What do the different aerodrome sign colours mean?
Red with white text is mandatory and means do not pass without clearance. Yellow with black text gives direction. Black with yellow text tells you your current location.
Master the details that win marks. Practise EASA ATPL questions on aerodrome markings, Air Law and Operational Procedures at atpltraining.io.
Photo by Alexandre Daoust on Unsplash
