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

II-3-1-2 Procedures — Aircraft Operations — Volume II
23/11/06
1.2.4 Maximum area width
There is no maximum area width for routes within the coverage of the facilities defining the route. Outside coverage of
the facilities defining the route, the area splays each side at 15°, as specified above in 1.2.3, “Area without track
guidance”.
1.2.5 Turn area
The obstacle clearance areas consist of a primary area; no buffer areas are applied. Turn area construction is described
in 1.4, “Construction of areas for VOR and NDB routes”.
1.3 OBSTACLE CLEARANCE
1.3.1 Minimum obstacle clearance (MOC)
1.3.1.1 The minimum obstacle clearance value to be applied in the primary area for the en-route phase of an IFR
flight is 300 m (984 ft). In the buffer area, the minimum obstacle clearance is equal to half the value of the primary area
MOC (see Figure II-3-1-1).
1.3.1.2 A minimum altitude is determined and published for each segment of the route. Charting accuracies must
be taken into account when establishing minimum altitudes by adding both a vertical and a horizontal tolerance to the
depicted objects on the chart, as specified in Part I, Section 2, Chapter 1, 1.7, “Increased altitude/heights for
mountainous areas”.
1.3.2 MOC in mountainous areas
1.3.2.1 In mountainous areas, the MOC shall be increased, depending on variation in terrain elevation as shown in
the table below. The MOC in the buffer area is half the value of the primary area MOC (see Figure II-3-1-1).
Elevation MOC
Between 900 m (3 000 ft) and 1 500 m (5 000 ft) 450 m (1 476 ft)
Greater than 1 500 m (5 000 ft) 600 m (1 969 ft)
1.3.2.2 Mountainous areas shall be identified by the State and promulgated in the State Aeronautical Information
Publication (AIP), section GEN 3.3.5, “The criteria used to determine minimum flight altitudes”.
1.3.3 MOC for turns
The full MOC applies over the total width of the turning area as shown in Figure II-3-1-5. There is no buffer area.
1.3.4 MOC when no track guidance provided
When track guidance is not provided, for example outside the coverage of navigation facilities along the route, the
primary area splays each side at an angle of 15° from its width at the last point where track guidance was available. The