4.2.3.1.1 — General Besluit toezicht luchtvaart BES
General
4.2.3.1.1.1 A new obstacle located in the vicinity of an existing obstacle and assessed as not being a hazard to aircraft is deemed to be shielded.
4.2.3.1.1.2 Unless specifically directed by the Authority, a shielded obstacle does not require removal, lowering, marking or lighting and should not impose any additional restrictions to aircraft operations.
4.2.3.1.1.3 DCANA shall assess and determine whether an obstacle is shielded. The aerodrome operator is to notify the Authority of the presence of all obstacles.
4.2.3.1.1.4 Only existing permanent obstacles may be considered in assessing shielding of new obstacles.
4.2.3.1.1.5 In assessing whether an existing obstacle shields an obstacle, DCANA will be guided by the principles of shielding detailed below.
4.2.3.1.1.6 Obstacles penetrating the approach and take-off climb surfaces
(a) (a) An existing obstacle within the approach and take-off climb area is called the critical obstacle. Where a number of obstacles exist closely together, the critical obstacle is the one which subtends the greatest vertical angle measured from the appropriate inner edge.
(b) (b) As illustrated below, a new obstacle may be assessed as not imposing additional restrictions if:
(i) when located between the inner edge end and the critical obstacle, the new obstacle is below a plane sloping downwards at 10% from the top of the critical obstacle toward the inner edge;
(ii) when located beyond the critical obstacle from the inner edge end, the new obstacle is not higher than the height of the permanent obstacle;
(iii) where there is more than one critical obstacle within the approach and take-off climb area, and the new obstacle is located between two critical obstacles, the height of the new obstacle is not above a plane sloping downwards at 10% from the top of the next critical obstacle.
4.2.3.1.1.7 Obstacles penetrating the inner and outer horizontal and conical surfaces.The new obstacle may be accepted if it is in the vicinity of an existing obstacle, and does not penetrate a 10% downward sloping conical shaped surface from the top of the existing obstacle, i.e. the new obstacle is shielded radially by the existing obstacle.
4.2.3.1.1.8 Obstacles Penetrating the Transitional Surfaces.A new obstacle maybe assessed as not imposing additional restrictions if it does not exceed the height of an existing obstacle which is closer to the runway strip and the new obstacle is located perpendicularly behind the existing obstacle relative to the runway centerline.
Note – Circumstances in which the shielding principle may reasonably be applied are described in the Airport Services Manual, Part 6.
4.2.4 New objects or extensions of existing objects shall not be permitted above the conical surface or inner horizontal surface except when, in the opinion of the DCA NA, the object would be shielded by an existing immovable object, or after aeronautical study it is determined that the object would not adversely affect the safety or significantly affect the regularity of operations of airplanes.
4.2.5 Existing objects above any of the surfaces required by 4.2.1 shall as far as practicable be removed except when, in the opinion of the DCA NA, the object is shielded by an existing immovable object, or after aeronautical study it is determined that the object would not adversely affect the safety or significantly affect the regularity of operations of airplanes.
Note – Because of transverse or longitudinal slopes on a strip, in certain cases the inner edge or portions of the inner edge of the approach surface may be below the corresponding elevation of the strip. It is not intended that the strip be graded to conform with the inner edge of the approach surface, nor is it intended that terrain or objects which are above the approach surface beyond the end of the strip, but below the level of the strip, be removed unless it is considered they may endanger airplanes.
4.2.6 In considering proposed construction, account shall be taken of the possible future development of an instrument runway and consequent requirement for more stringent obstacle limitation surfaces.
- Regeling
- Besluit toezicht luchtvaart BES
- Soort
- AMvB-BES
- Geldend vanaf
- 01-01-2021
- BWB-id
- BWBR0028721
- Versie
- 2021-01-01_0