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

I-4-6-10 Procedures — Aircraft Operations — Volume II
b) move SOC back to increase dz. This means that the MAPt and consequently earliest TP will be moved and the
turn areas extended accordingly; and
c) increase OCA/H.
6.4.5.6 Safeguarding of early turns
If the procedure does not prohibit turns before the MAPt, then an additional area outside the final approach area must
be considered (see Figure I-4-6-14). In this area obstacle elevation shall be less than:
23/11/06
TNA/H + do tan Z – 50 m (164 ft)
(Cat H, TNA/H + do tanZ–40m(132ft))
where do is measured from the obstacle to the nearest point on the edge of the final approach area. If this criterion
cannot be met, then the procedure must prohibit turns before the MAPt and a note must be added on the profile view of
the approach chart.
6.4.6 Turn initiated at a designated turning point
6.4.6.1 General. A designated TP shall be defined by a fix (see Section 2, Chapter 2, 2.3 and 2.4), or by a limiting
radial, bearing or DME distance (see Section 2, Chapter 2, 2.6.5). It is chosen to allow the aircraft to avoid an obstacle
straight ahead. The straight missed approach criteria apply up to the earliest TP. This allows the calculation of OCA/H
for final and straight missed approach (OCA/Hfm) (see 6.2 “Climb gradient and MOC”). SOC is then determined.
6.4.6.2 Turning point tolerance area. The length of the TP tolerance area is determined by:
a) the limits of the fix tolerance area, plus;
b) an additional distance c (pilot reaction and bank establishing time) equivalent to 6 seconds of flight at final
missed approach (or maximum published missed approach) speed plus 56 km/h (30 kt) tailwind (see
Figure I-4-6-15). Some example values of c are shown in Tables I-4-6-5 and I-4-6-6.
If the TP is defined by overheading a facility (e.g. VOR, NDB) the TP fix tolerance can be taken as ± 0.9 km
(± 0.5 NM) up to a height above the facility of:
i) 750 m (2 500 ft) for a VOR (with a cone angle of 50°); and
ii) 1 100 m (3 600 ft) for an NDB.
6.4.6.3 Construction of the turn area
6.4.6.3.1 Turns are executed in the final missed approach area. This area begins at point A, which is located at the
latest limit of the TP tolerance area (defined above). Its sides begin at the edges of the straight missed approach area.
6.4.6.3.2 TP defined by a fix or by a limiting radial, bearing or DME distance.
a) Outer boundary:
1) On the outside edge of the missed approach area, determine point A (see Figure I-4-6-15).