---
title: "CS ADR-DSN.M.665 Runway lead-in lighting systems — Certification Specifications and Guidance Material for Aerodrome Design (CS-ADR-DSN) — Issue 7, Aerodromes · Avioverse"
description: "Applicability: A runway lead-in lighting system should be provided to avoid hazardous terrain."
url: "https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-m-visual-aids-for-navigation-lights/cs-adr-dsn-m-665"
---

# CS ADR-DSN.M.665 Runway lead-in lighting systems

Certification Specifications and Guidance Material for Aerodrome Design (CS-ADR-DSN) — Issue 7 · Regulation (EU) No 139/2014 · EAR revision 13 Mar 2026

Official sources: [EASA Easy Access Rules (opens in a new tab)](https://www.easa.europa.eu/en/document-library/easy-access-rules/easy-access-rules-aerodromes) · [EUR-Lex 2014/139 (opens in a new tab)](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32014R0139)

IR Implementing rule

## CS ADR-DSN.M.665 Runway lead-in lighting systems

(a) Applicability: A [runway](https://avioverse.aero/glossary/easa/runway) lead-in lighting system should be provided to avoid hazardous terrain.

(b) Location and positioning

(1) A runway lead-in lighting system should consist of groups of lights positioned:

(i) so as to define the desired approach path. Runway lead-in lighting systems may be curved, straight, or a combination thereof; and

(ii) so that one group should be sighted from the preceding group.

(2) The interval between adjacent groups should not exceed approximately 1 600 m.

(3) A runway lead-in lighting system should extend from a determined point up to a point where the approach lighting system if provided, or the runway lighting system is in view.

(4) Each group of lights of a runway lead-in lighting system should consist of at least three flashing lights in a linear or cluster configuration. The system should be augmented by steady burning lights where such lights would assist in identifying the system.

(c) Characteristics: The flashing lights and the steady burning lights should be white.

\[Issue: ADR-DSN/4]

IR · CS ADR-DSN.M.665 — Regulation (EU) No 139/2014 · ED Decision 2017/021/R · Aerodromes Easy Access Rules · EAR revision 13 Mar 2026

[All rules in CHAPTER M — VISUAL AIDS FOR NAVIGATION (LIGHTS)](https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-m-visual-aids-for-navigation-lights)

Consolidated from the EASA Easy Access Rules (revision 13 Mar 2026, extracted 2 Nov 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.