---
title: "CS ADR-DSN.R.870 Unserviceable areas — Certification Specifications and Guidance Material for Aerodrome Design (CS-ADR-DSN) — Issue 7, Aerodromes · Avioverse"
description: "Characteristics: Unserviceability markers should consist of conspicuous upstanding devices such as flags, cones, or marker boards."
url: "https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-r-visual-aids-for-denoting-restricted-use/cs-adr-dsn-r-870"
---

# CS ADR-DSN.R.870 Unserviceable areas

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

IR Implementing rule

## CS ADR-DSN.R.870 Unserviceable areas

(a) Characteristics:

(1) Unserviceability markers should consist of conspicuous upstanding devices such as flags, cones, or [marker](https://avioverse.aero/glossary/easa/marker) boards.

(2) An unserviceability light should consist of a red [fixed light](https://avioverse.aero/glossary/easa/fixed-light). The light should have intensity sufficient to ensure conspicuity considering the intensity of the adjacent lights and the general level of illumination against which it would normally be viewed. In no case should the intensity be less than 10 cd of red light.

(3) An unserviceability cone should be at least 0.5 m in height and red, orange, or yellow, or any one of these colours in combination with white.

(4) An unserviceability flag should be at least 0.5 m square and red, orange, or yellow, or any one of these colours in combination with white.

(5) An unserviceability marker board should be at least 0.5 m in height and 0.9 m in length, with alternate red and white, or orange and white vertical stripes.

\[Issue: ADR-DSN/7]

IR · CS ADR-DSN.R.870 — Regulation (EU) No 139/2014 · ED Decision 2025/004/R · Aerodromes Easy Access Rules · EAR revision 13 Mar 2026

[All rules in CHAPTER R — VISUAL AIDS FOR DENOTING RESTRICTED USE AREAS](https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-r-visual-aids-for-denoting-restricted-use)

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