1. Aerodrome training Course – module 4 Control of Obstacles

2. CONTROL OF OBSTACLES Learning Outcome On completion of this module students will be able to explain the requirements for controlling obstacles to facilitate an airport operation. They will be able to: • Explain the basic requirements and inter-relationship between :- - Obstacle Protection Surfaces - Obstacle Assessment Obstacle Limitation • With access to reference material detail the specific dimensions of an Airports Obstacle Limitation Surfaces

3. Obstacle Limitation Surfaces (ANNEX 14) Obstacle Assessment Surfaces (PANS OPS Doc 8168) • ANNEX 14 Obstacle Limitation Surfaces The broad purpose of these surfaces is to define the volume of airspace around aerodromes to be maintained free from obstacles so as to permit the intended aeroplane operations at the aerodrome to be conducted safely and to prevent the aerodromes from becoming unusable by the growth of obstacles. This is achieved by establishing a series of OLS that define the limits to which objects may project into the airspace • PANS OPS Obstacle Assessment Surfaces These surfaces are intended for use by procedure designers for the construction of instrument flight procedures and for specifying minimum safe altitudes/heights for each segment of the procedure

4. ANNEX 14 Annex 14 Obstacle Limitation Surfaces • Transitional Surfaces • Inner Horizontal • Conical • Outer Horizontal • Approach • Take-off climb • Balked Landing (Precision) • Obstacle Free Zone (Precision Cat 2 & 3) • PANS OPS DOC 8168 Obstacle Assessment Surfaces • Instrument Approach Surfaces Annex 14 Obstacle Protection Surface • Circling • Departure Surfaces • for VASIS/PAPI

5. Annex 14 OLS Purple –Inner Horizontal, conical, Outer horizontal Obstacle Limitation Surfaces Green Approach Red Take-off climb

6. Obstacle Limitation Surfaces

7. OLS Dimensions

8. Annex 14 Transition OLS

9. Transition OLS

10. Annex 14 Approach Surface

11. Annex 14 Approach Surface

12. Annex 14 Transition and Approach Surfaces

13. Inner Horizontal surface 4000m radius from Reference Point 45m above a runway elevation datum Refer AerodromeServices Manual Part 6 Where surfaces overlap the lower surface should be regarded as dominant Conical surface from Horizontal surface 45m at slope of 5% to 100m Inner Horizontal and Conical

14. Annex 14 Take-off Surfaces Code 3 & 4

15. 6480m 60m from Runway End* *The take-off climb surface starts at the end of the clearway if the clearway length exceeds the specified distance. Refer Annex 14 Table 4-2 Annex 14 Take-off 1.6%

16. *The take-off climb surface starts at the end of the clearway if the clearway length exceeds the specified distance. Refer Annex 14 Table 4-2 Annex 14 Take-off 2.0%

17. ANNEX 14 Obstacle Free Zone

18. Obstacle Free Zone • Obstacle Free Zone is established for Precision Category I (recommended), II, III operations • Inner approach, Inner Transitional and Balked Landing surfaces create the Obstacle Free Zone for precision approach operations Reference: Description of ANNEX 14 4-3 Doc 9137 Part 6 Obstacle Free Zone

19. ANNEX 14 Obstacle Protection Surface

20. ANNEX 14Figure 5 -20 Obstacle protection surface for visual approach slope indicator system

21. ANNEX 14Figure 5 -20 Dimensions and slopes of the obstacle protection surfaces

22. PANS OPSSURFACES

23. OCA/H for Visual manoeuvring (Circling) Aircraft Radius from Thres Obstacle clearance Lowest OCH above Aerodrome Category (R) m A 3.12 90 120(394ft) B 4.90 90 150(492ft) C 7.85 120 180(591ft) D 9.79 120 210(689ft) E 12.82 150 240(787ft) PANS OPS 8168 Circling Area

24. PANS OPS 8168 VOR Approach surfaces

25. Relationship between different surfaces 1 in 7 Side Transition, Inner Horizontal and Conical, Annex 14 Approach, VOR Approach

26. PANS OPS 8168 Basic ILS obstacle assessment surfaces

27. ILS Collision Risk Model

28. Visual Segment Surface • All new straight-in instrument approach procedures published on or after 15 March 2007 shall be protected for obstacles in the visual segment. Straight-in instrument approach procedures published before 15 March 2007 shall be protected in the visual segment by means of the VSS after the periodical review of the procedure, but not later than 15 March 2012. • Dimensions • a base width of 300 m (150 m either side of the extended runway centreline) for a Code 3 and 4 runway and 150 m (75 m either side of the extended runway centreline) for Code 1 and 2, originating 60 m prior to the runway threshold, splaying 15 per cent on either side of the extended runway centreline, and terminating at the point where the height of the surface reaches the OCH • where the final approach course is offset and intersects the extended runway centreline, the splay on the side closest to the final approach course is increased by the offset angle. Vertically, the VSS originates at the runway threshold height and has a slope of 1.12 degrees less than the promulgated approach procedure angle

29. Departure 2.5% Obstacle assessment surface to protect aircraft climbing at 3.3% PANS OPS 8168 Departure Surface

30. Annex 14 Take-off surfaceswith PANS OPS 8168 Departure Surface

31. Obstacle Assessments using OLS

32. 3D view of Take-off OLS Annex 14 surface showing penetration of terrain

33. OLS Existing with structures included

34. 3D modelling used to highlite proposed structures (RED) are below proposed raised OLS (yellow) but existing structures (BLUE) penetrate this surface

35. Initial Approach surfaces Intermediate Approach surfaces VOR/DME approach surface showing Nil penetration of obstacles

36. Practical Exercises • Calculate the height that an obstacle can be erected above an instrument runway precision Code 4 given: on extended centreline distance from threshold 4000m? • What OLS will control the height of an obstacle to be erected adjacent to midpoint of a Code 4 instrument runway at 320m for runway centreline?