--- title: "CS ADR-DSN.N.780 Mandatory instruction signs — Certification Specifications and Guidance Material for Aerodrome Design (CS-ADR-DSN) — Issue 7, Aerodromes · Avioverse" description: "Applicability: A mandatory instruction sign should be provided to identify a location beyond which an aircraft taxiing or vehicle should not proceed…" url: "https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-n-visual-aids-for-navigation-signs/cs-adr-dsn-n-780" --- # CS ADR-DSN.N.780 Mandatory instruction signs 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.N.780 Mandatory instruction signs (a) Applicability: (1) A mandatory instruction [sign](https://avioverse.aero/glossary/easa/sign) should be provided to identify a location beyond which an [aircraft](https://avioverse.aero/glossary/easa/aircraft) taxiing or vehicle should not proceed unless authorised by the [aerodrome](https://avioverse.aero/glossary/easa/aerodrome) control tower. (2) Mandatory instruction signs should include [runway](https://avioverse.aero/glossary/easa/runway) designation signs, Category I, II, or III holding position signs, [runway-holding position](https://avioverse.aero/glossary/easa/runway-holding-position) signs, [road-holding position](https://avioverse.aero/glossary/easa/road-holding-position) signs, and noentry signs. (3) A pattern ‘A’ runway-holding position [marking](https://avioverse.aero/glossary/easa/marking) should be supplemented at a [taxiway](https://avioverse.aero/glossary/easa/taxiway)/runway intersection or a runway/runway intersection with a runway designation sign. (4) A pattern ‘B’ runway-holding position marking should be supplemented with a Category I, II, or III holding position sign. (5) A pattern ‘A’ runway-holding position marking at a runway-holding position should be supplemented with a runway-holding position sign. (6) A runway designation sign at a taxiway/runway intersection should be supplemented with a location sign in the outboard (farthest from the taxiway) position as appropriate. (7) A road-holding position sign should be provided at all [road](https://avioverse.aero/glossary/easa/road) entrances to a runway and may also be provided at road entrances to taxiways. (8) A no-entry sign should be provided when entry into an area is prohibited. (b) Location: (1) A runway designation sign at a taxiway/runway intersection or a runway/runway intersection should be located on each side of the runway-holding position marking facing the direction of approach to the runway. (2) A Category I, II, or III holding position sign should be located on each side of the runway-holding position marking facing the direction of the approach to the [critical area](https://avioverse.aero/glossary/easa/critical-area). (3) A no-entry sign should be located at the beginning of the area to which entrance is prohibited on each side of the taxiway as viewed by the pilot. (4) A runway-holding position sign should be located on each side of the runway-holding position facing the approach to the [obstacle limitation surface](https://avioverse.aero/glossary/easa/obstacle-limitation-surface) or ILS/MLS critical/[sensitive area](https://avioverse.aero/glossary/easa/sensitive-area) as appropriate. (c) Characteristics: (1) A mandatory instruction sign should consist of an inscription in white on a red background. Where, owing to environmental or other factors, the conspicuity of the inscription on a mandatory instruction sign needs to be enhanced, the outside edge of the white inscription should be supplemented by a black outline measuring 10 mm in width for runway code numbers 1 and 2, and 20 mm in width for runway code numbers 3 and 4. (2) The inscription on a runway designation sign should consist of the runway designations of the intersecting runway properly oriented with respect to the viewing position of the sign, except that a runway designation sign installed in the vicinity of a runway extremity may show the runway designation of the concerned runway extremity only. (3) The inscription on a Category I, II, III, joint II/III or joint I/II/III holding position sign should consist of the runway designator followed by CAT I, CAT II, CAT III, CAT II/III or CAT I/II/III, as appropriate. (4) The inscription on a no-entry sign should be in accordance with Figure N-4. (5) The inscription on a runway-holding position sign at a runway-holding position should consist of the taxiway designation and a number. (d) Where installed, the inscriptions/symbol of Figure N-4 should be used: \[Figure or form omitted from this preview — available in the Avioverse workspace library.] Figure N-4. Mandatory instruction signs \[Figure or form omitted from this preview — available in the Avioverse workspace library.] Note: Distance X is established in accordance with Table D-2. Distance Y is established at the edge of ILS/MLS critical/sensitive area Figure N-5. Positions of signs at taxiway/runway intersections \[Issue: ADR-DSN/3] \[Issue: ADR-DSN/4] \[Issue: ADR-DSN/6] IR · CS ADR-DSN.N.780 — Regulation (EU) No 139/2014 · ED Decision 2022/006/R · Aerodromes Easy Access Rules · EAR revision 13 Mar 2026 [All rules in CHAPTER N — VISUAL AIDS FOR NAVIGATION (SIGNS)](https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-n-visual-aids-for-navigation-signs) 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.