IRImplementing rule
CS ADR-DSN.M.655Obstacle protection surface for PAPI and APAPI
(a)Applicability: An obstacle protection surface should be established when it is intended to provide a visual approach slope indicator system.
(b)Characteristics: The characteristics of the obstacle protection surface, i.e. origin, divergence, length, and slope should correspond to those specified in the relevant column of Table M-2 and in Figure M-6.
(c)New objects or extensions of existing objects should not be permitted above an obstacle protection surface except when the new object or extension would be shielded by an existing immovable object, or if after a safety assessment, it is determined that the object would not adversely affect the safety of operations of aeroplanes.
(d)Where a safety assessment indicates that an existing object extending above an obstacle protection surface could adversely affect the safety of operations of aeroplanes one or more of the following measures should be taken:
(1)remove the object;
(2)suitably raise the approach slope of the system;
(3)reduce the azimuth spread of the system so that the object is outside the confines of the beam;
(4)displace the axis of the system and its associated obstacle protection surface by no more than 5°;
(5)suitably displace the threshold; and
(6)where (5) is found to be impracticable, suitably displace the system upwind of the threshold such that the object no longer penetrates the obstacle protection surface.
| Runway type/code number | ||||||||
|---|---|---|---|---|---|---|---|---|
| Non-instrument | Instrument | |||||||
| Code number | Code number | |||||||
| Surface dimensions | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 |
| Length of inner edge | 60 m | 80 m | 150 m | 150 m | 150 m | 150 m | 300 m | 300 m |
| Distance from the visual approach slope indicator system2 | D1+30 m | D1+60 m | D1+60 m | D1+60 m | D1+60 m | D1+60 m | D1+60 m | D1+60 m |
| Divergence (each side) | 10 % | 10 % | 10 % | 10 % | 15 % | 15 % | 15 % | 15 % |
| Total length | 7 500 m | 7 500 m | 15 000 m | 15 000 m | 7 500 m | 7 500 m | 15 000 m | 15 000 m |
| Slope | ||||||||
| a) PAPI1 | ― | A–0.57° | A–0.57° | A–0.57° | A–0.57° | A–0.57° | A–0.57° | A–0.57° |
| b) APAPI1 | A–0.9° | A–0.9° | – | – | A–0.9° | A–0.9° | – | – |
| 1 Angles as indicated in Figure M-5. 2 D1 is the distance of the visual approach slope indicator system from threshold prior to any displacement to remedy object penetration of the obstacle protection surface (refer to Figure M-4). The start of the obstacle protection surface is fixed to the visual approach slope indicator system location, such that displacement of the PAPI results in an equal displacement of the start of the obstacle protection surface. | ||||||||
Table M-2. Dimensions and slopes of the obstacle protection surface
[Figure or form omitted from this preview — available in the Avioverse workspace library.] Figure M-6. Obstacle protection surface for visual approach slope indicator systems
[Issue: ADR-DSN/3]
[Issue: ADR-DSN/4]
[Issue: ADR-DSN/6]
IR · CS ADR-DSN.M.655 — Regulation (EU) No 139/2014 · ED Decision 2022/006/R · Aerodromes Easy Access Rules · EAR revision 13 Mar 2026