---
title: "CS ADR-DSN.H.450 Inner approach surface — Certification Specifications and Guidance Material for Aerodrome Design (CS-ADR-DSN) — Issue 7, Aerodromes · Avioverse"
description: "Applicability: The purpose of the inner approach surface is to protect final precision approaches."
url: "https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-h-obstacle-limitation-surfaces/cs-adr-dsn-h-450"
---

# CS ADR-DSN.H.450 Inner approach surface

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.H.450 Inner approach surface

(a) Applicability: The purpose of the inner approach surface is to protect final precision approaches.

(b) Description: A rectangular portion of the approach surface immediately preceding the [threshold](https://avioverse.aero/glossary/easa/threshold).

(c) Characteristics: The limits of the inner approach surface should comprise:

(1) an inner edge coincident with the location of the inner edge of the approach surface but of its own specified length;

(2) two sides originating at the ends of the inner edge and extending parallel to the vertical plane containing the centre line of the [runway](https://avioverse.aero/glossary/easa/runway); and

(3) an outer edge parallel to the inner edge.

IR · CS ADR-DSN.H.450 — Regulation (EU) No 139/2014 · ED Decision 2014/013/R · Aerodromes Easy Access Rules · EAR revision 13 Mar 2026

[All rules in CHAPTER H — OBSTACLE LIMITATION SURFACES](https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-h-obstacle-limitation-surfaces)

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.