Aircraft Operations. Volume II - Construction of Visual and Instrument ...

II-2-4-2 Procedures — Aircraft Operations — Volume II
23/11/06
4.4.4 Area
4.4.4.1 The area considered for obstacle clearance in the final approach segment starts at the FAF and ends at the
MAPt. It is a portion of a 37 km (20 NM) (NDB: 28 km (15 NM)) long trapezoid which is made up of primary and
secondary areas. The area is centred longitudinally on the final approach track. It is 3.7 km (2.0 NM) wide at the facility
and splays uniformly at an angle of 7.8° either side of the area to 37 km (20 NM) from the VOR (28 km (15 NM) from
the NDB). The inner 50 per cent of the area is the primary area, while the outer 25 per cent on each side of the primary
area is the secondary area.
4.4.4.2 Final approach may be made to aerodromes which are a maximum of 37 km (20 NM) from the VOR
(28 km (15 NM) from the NDB). However, only that portion of the 37 km (20 NM) (NDB: 28 km (15 NM)) trapezoid
which falls between the FAF and the MAPt shall be considered as the final approach segment for obstacle clearance
purposes. See Figure II-2-4-4.
4.4.4.3 The optimum length of the final approach segment is 9 km (5 NM) (Cat H, 3.7 km (2 NM)). The
maximum length should not normally be greater than 19 km (10 NM) (see Part I, Section 4, Chapter 5, 5.4.5.2 b),
“Excessive length of final approach” for excessive length consideration). The minimum length shall provide adequate
distance for an aircraft to make the required descent, and to regain track alignment when a turn is required over the
FAF. Table II-2-4-1 shall be used to determine the minimum length needed to regain the track after a turn over the FAF.
4.4.4.4 If the turn at the FAF is greater than 10° the final approach area should be widened on the outer side of the
turn as specified in Part I, Section 4, Chapter 6, 6.4.6.3.2, “TP marked by a facility (NDB or VOR)”.
4.4.5 Station providing track guidance
When more than one facility is on the final approach track, the facility to be used for track guidance for final approach
shall be clearly identified.
4.4.6 Obstacle clearance
4.4.6.1 Straight-in approach. The minimum obstacle clearance in the primary area is 75 m (246 ft). In the
secondary area 75 m (246 ft) of clearance shall be provided over all obstacles at the inner edge, tapering uniformly to
zero at the outer edge. See Part I, Section 4, Chapter 5, 5.4.5.2 b), “Excessive length of final approach” for increased
MOC due to excessive length of final segment and Part I, Section 2, Chapter 1, 1.7, “Increased altitudes/heights for
mountainous areas”.
4.4.6.2 Circling approach. Obstacle clearance in the visual manoeuvring area shall be as described in Part I,
Section 4, Chapter 7, “Visual manoeuvring (circling) area”.
4.5 MISSED APPROACH POINT (MAPt)
4.5.1 Off-aerodrome facility — Straight-in approach
The MAPt is located at a point on the final approach track which is not farther from the FAF than the threshold. See
Figure II-2-4-4.