---
title: "GM1 ADR-DSN.H.455 Inner transitional surface — Certification Specifications and Guidance Material for Aerodrome Design (CS-ADR-DSN) — Issue 7, Aerodromes · Avioverse"
description: "It is intended that the inner transitional surface be the controlling obstacle limitation surface for navigation aids, aircraft, and other vehicles that…"
url: "https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-h-obstacle-limitation-surfaces/gm1-adr-dsn-h-455"
---

# GM1 ADR-DSN.H.455 Inner transitional surface

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

GM Guidance material

## GM1 ADR-DSN.H.455 Inner transitional surface

(a) It is intended that the inner transitional surface be the controlling [obstacle limitation surface](https://avioverse.aero/glossary/easa/obstacle-limitation-surface) for navigation aids, [aircraft](https://avioverse.aero/glossary/easa/aircraft), and other vehicles that should be near the [runway](https://avioverse.aero/glossary/easa/runway), and which is not to be penetrated except for frangible objects. The transitional surface is intended to remain as the controlling obstacle limitation surface for buildings, etc.

(b) The inner transitional surface along the strip should be curved if the runway profile is curved or a plane if the runway profile is a straight line. The intersection of the inner transitional surface with the inner horizontal surface should also be a curved or straight line depending on the runway profile.

GM · GM1 ADR-DSN.H.455 — 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.