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

III-3-2-2 Procedures — Aircraft Operations — Volume II
23/11/06
2.1.5 Y- or T-bar design concept for RNAV procedures
For a detailed description of non-precision approach procedures based on the Y- or T-bar concept, refer to Section 2,
Chapter 3, Y- or T-bar procedure construction”.
2.2 ARRIVAL ROUTES
2.2.1 General
Arrival obstacle clearance criteria shall apply up to the initial or intermediate approach fix (see Part I, Section 4,
Chapter 2).
2.2.2 Minimum sector altitude/terminal arrival altitude
For terminal arrival altitude see Section 2, Chapter 4, “TAA”. Where TAAs are not provided, a minimum sector
altitude shall be published. The provisions of Part I, Section 4, Chapter 8, “Minimum sector altitudes (MSA)” apply
except that only a single omnidirectional sector shall be established in the case of GNSS. The sector is centred on the
latitude and longitude of the aerodrome reference point.
2.2.3 Area width for VOR/DME and DME/DME
2.2.3.1 With VOR/DME, DME/DME the area tapers evenly from the beginning of the arrival segment to the
width at the IAF (or IF, as appropriate) at a maximum convergence angle of 30°. See Figure III-3-2-1.
2.2.3.2 The area width at the beginning of the segment differs according to its distance from the IAF (or IF, as
appropriate).
a) Arrival routes which start more than 46 km (25 NM) from the IAF. The ½ A/W at the beginning of this area is
the greater of the following values:
1) 9.26 km (5.00 NM); or
2) (1.5 XTT + 3.70 km (2.00 NM)) where XTT is determined with FTT = 3.70 km (2.00 NM).
b) Arrival routes which start 46 km (25 NM) or less from the IAF. The ½ A/W at the beginning of this area is the
greater of the following values:
1) 9.26 km (5.00 NM); or
2) (1.5 XTT + 1.85 km (1.00 NM)) where XTT is determined with FTT = 1.85 km (1.00 NM).
2.2.4 Area width for basic GNSS
In addition to the general arrival criteria, Part I, Section 4, Chapter 2 , the following criteria apply. For basic GNSS area
semi-width see Section 1, Chapter 2, 2.5, “XTT, ATT and area semi-width”. The area width tapers at an angle of 30°
each side of the axis, perpendicular to the point where the 56 km (30 NM) arc from the aerodrome reference point
(ARP) intercepts the nominal track. Contrary to the general arrival criteria, the en-route width shall be used when more
than 56 km (30 NM) from the ARP. See Figures III-3-2-2 and III-3-2-3.