What does EASA CS-ADR-DSN require for airfield lighting?
Chapter M says which lights an aerodrome needs. Colour and intensity, power and monitoring, siting and obstacle lighting sit in four other chapters, so a complete requirement is read across all five.
CS-ADR-DSN is EASA's certification specification for aerodrome design. It applies to aerodromes within the scope of the EU Basic Regulation, Regulation (EU) 2018/1139. Each requirement is a CS paragraph, and the GM1 paragraph after it gives guidance on applying it.
Lighting is spread across chapters. Chapter M sets which lights an aerodrome provides and how they are arranged. U fixes colour and intensity, S the secondary power and monitoring, T frangibility and siting, and Q the lighting of obstacles. A requirement read from M alone is incomplete.
This page is written against Issue 7. Since Issue 5 the lighting paragraphs point to Part-ADR.OPS (ADR.OPS.C.015) for serviceability levels, and Issue 7 aligned more of CS-ADR-DSN with that operational rulebook, so read the two together.
- Fix the runway type. Non-instrument, non-precision, Category I, Category II or III, or take-off in low visibility.
- Find the light in Chapter M. Use the paragraph finder below.
- Check colour and intensity. Chapter U, paragraphs U.930 and U.940.
- Check power and monitoring. Chapter S: switch-over time in Table S-1 and automatic monitoring.
- Check siting and obstacles. Frangibility and siting in Chapter T, then obstacle lights from Chapter Q.
Arrangement, colour, intensity, power, siting and obstacle lighting are all checked, so design review leaves no gap for inspection to find.
The light may sit in the right place yet have the wrong intensity, no suitable secondary supply or a rigid mounting, and the gap shows at certification.
Chapter M at a glance
Every Chapter M paragraph, grouped by where the light sits on the aerodrome. Underlined titles open the encyclopedia entry for that light.
General and beaconsM.615 to M.620
- M.615General
- M.620Aeronautical beacons
Approach lightingM.625 to M.635
- M.625Approach lighting systems
- M.626Simple approach lighting systems
- M.630Precision approach Category I lighting system
- M.635Precision approach Category II and III lighting system
Visual slope guidanceM.640 to M.655
- M.640Visual approach slope indicator systems
- M.645PAPI and APAPI
- M.650Approach slope and elevation setting of light units for PAPI and APAPI
- M.655Obstacle protection surface for PAPI and APAPI
Runway lightsM.660 to M.706
- M.660Circling guidance lights
- M.665Runway lead-in lighting systems
- M.670Runway threshold identification lights
- M.675Runway edge lights
- M.680Runway threshold and wing bar lights
- M.685Runway end lights
- M.690Runway centre line lights
- M.695Runway touchdown zone lights
- M.696Simple touchdown zone lights
- M.700Rapid exit taxiway indicator lights (RETILs)
- M.705Stopway lights
- M.706Runway status lights (RWSL)
Taxiway and holding lightsM.710 to M.745
- M.710Taxiway centre line lights
- M.715Taxiway centre line lights on taxiways, runways, rapid exit taxiways or other exit taxiways
- M.720Taxiway edge lights
- M.725Runway turn pad lights
- M.730Stop bars
- M.735Intermediate holding position lights
- M.740De-icing/anti-icing facility exit lights
- M.745Runway guard lights
Apron, docking and accessM.750 to M.771
- M.750Apron floodlighting
- M.755Visual docking guidance system
- M.760Advanced visual docking guidance system
- M.765Aircraft stand manoeuvring guidance lights
- M.770Road-holding position light
- M.771No-entry bar
Lighting also appears outside Chapter M. These paragraphs are read alongside it.
Chapter UColour and characteristics
Chapter SElectrical systems
- S.875Electrical power supply systems for air navigation facilities
- S.880Electrical power supply systems
- S.885System design
- S.890Monitoring
Chapter TEquipment and siting
- T.910Equipment frangibility requirements
- T.915Siting of equipment and installations on operational areas
- T.921Autonomous runway incursion warning system (ARIWS)
Chapter QObstacle lighting
- Q.846Lighting of fixed objects
- Q.847Fixed objects under 45 m above ground level
- Q.848Fixed objects from 45 m to under 150 m
- Q.849Fixed objects of 150 m or more
- Q.851Marking and lighting of wind turbines
- Q.852Overhead wires, cables, supporting towers and similar
Chapter RRestricted use areas
- R.855Closed runways and taxiways, or parts thereof
- R.870Unserviceable areas
Switch-over time: 1 second or 15 seconds
Table S-1 sets the longest time a light may take to switch to the secondary power supply. The tightest limit, one second, is kept for the lights that guide an aircraft in the lowest visibility. Bar length shows the time allowed.
Non-precision approach
- Approach lighting system
- Visual approach slope indicators
- Runway edge
- Runway threshold
- Runway end
- Obstacle
- Stopway end
- Stopway edge
Precision approach, Category I
- Approach lighting system
- Runway edge
- Runway threshold
- Runway end
- Visual approach slope indicators
- Essential taxiway
- Obstacle
- Stopway end
- Stopway edge
Precision approach, Categories II and III
- Inner 300 m of approach lighting
- Runway threshold
- Runway end
- Runway centre line
- Runway touchdown zone
- All stop bars
- Stopway end
- Other parts of approach lighting
- Runway edge
- Runway guard lights
- Essential taxiway
- Obstacle
- Stopway edge
Take-off in low visibility
- Runway end
- Runway centre line
- All stop bars
- Stopway end
- Runway edge
- Essential taxiway
- Obstacle
Automatic monitoring. For a runway meant for use in RVR conditions below 550 m, the lighting systems in Table S-1 are monitored automatically so that a fault is indicated (CS ADR-DSN.S.890).
Read the table notes. Some entries carry conditions. Visual approach slope indicators, obstacle lights and essential taxiway lights need secondary power only where their operation is essential to the safety of flight operations. For non-precision and Category I runways, the approach-related lights (such as runway edge, threshold and slope indicators) change from 15 seconds to one second where approaches are over hazardous or precipitous terrain. For low-visibility take-off, the runway edge lights are one second where no runway centre line lights are provided. The lists above are a learning summary of Table S-1, not the whole table, so check S.880 in the issue your certification basis cites before sizing a UPS or generator.
How the lighting rules changed
CS-ADR-DSN is reissued from time to time, so quote the issue with the paragraph. These are the lighting changes listed in the Issue 7 preamble.
- ISSUE7
Aligned CS-ADR-DSN with the operational provisions that moved to Part-ADR.OPS. Amended Q.852 (overhead wires, cables and towers) and the closed and unserviceable area paragraphs R.855 and R.870.
- ISSUE6
Amended PAPI and APAPI setting and obstacle protection (M.650, M.655), taxiway centre line lights (M.710, M.715), runway guard lights (M.745) and the no-entry bar (M.771), plus the sign and colour paragraphs N.775, N.785 and U.935.
- ISSUE5
Amended Category I and II/III approach lighting (M.630, M.635), runway centre line lights (M.690) and stopway lights (M.705), with an added case where stopway lights are provided for runway safety and a switch-over time for them. Revised S.880 and S.890, and pointed serviceability references at Part-ADR.OPS.
- ISSUE4
Added runway status lights (M.706) and the autonomous runway incursion warning system (T.921). Amended many Chapter M light paragraphs, together with U.930 and U.940.
- ISSUE3
Added simple touchdown zone lights (M.696), the no-entry bar (M.771) and the obstacle marking and lighting paragraphs Q.845 to Q.849, Q.851 and Q.852.
Frequently Asked Questions
Q1Where are the lighting requirements in CS-ADR-DSN?
Most of them are in Chapter M, which covers lights from approach lighting to docking guidance. Colour and light characteristics are in Chapter U, secondary power and monitoring in Chapter S, frangibility and siting in Chapter T, and obstacle lighting in Chapter Q. Lights on closed or unserviceable areas are in Chapter R.
Q2Are the CS-ADR-DSN paragraphs mandatory?
They are certification specifications: technical standards adopted by EASA as a means to show compliance, used for aerodrome certification. The text is worded with 'should', but it becomes the design basis for an aerodrome through its certification basis. If your design departs from a paragraph, agree the departure with your competent authority before you rely on it.
Q3Which aerodromes does CS-ADR-DSN cover?
Aerodromes within the scope of the EU Basic Regulation, Regulation (EU) 2018/1139. At an aerodrome with several runways, the specifications also apply to the other runways, such as non-instrument or unpaved ones. Surface-level VFR heliports at aerodromes have their own specification, CS-HPT-DSN.
Q4How quickly must backup power take over?
Table S-1 in Chapter S sets a maximum switch-over time for each lighting aid. On a precision approach Category II or III runway it is one second for the inner 300 m of the approach lights, the threshold, runway end, centre line, touchdown zone, stop bars and stopway end, and 15 seconds for the other lights listed. On Category I and non-precision approach runways the lights listed in the table are 15 seconds, but some approach-related lights drop to one second where approaches are over hazardous or precipitous terrain. Read the table notes before you size the supply.
Q5Where are the serviceability levels for lights set?
In Part-ADR.OPS, at ADR.OPS.C.015. The Chapter M lighting paragraphs refer to it rather than to CS ADR-DSN.S.895. For example, CS ADR-DSN.M.690 allows wider spacing of runway centre line lights only where those serviceability levels can be demonstrated and the runway is meant for use in RVR conditions of 350 m or greater. EASA's NPA 2026-01 (published 28 April 2026, comments closed 23 June 2026) proposes lowering that threshold to 300 m, so watch for the decision.
Q6Which issue of CS-ADR-DSN should I cite?
Cite the paragraph and the issue together, such as CS ADR-DSN.M.690 in Issue 7. Issue 7 (ED Decision 2025/004/R, applicable since 24 May 2025) is the latest issue listed in EASA's document library at the time of writing. Check the library for newer issues, and check which issue your aerodrome's certification basis refers to.
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