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

Part I — Section 4, Chapter 5 I-4-5-7
d) Visual manoeuvring (circling). For visual manoeuvring (circling) a lower limit consisting of the OCA/H for the
associated instrument approach procedure is applied (see 5.4.4, “OCA/H for visual manoeuvring (circling)”).
5.5 PROMULGATION
5.5.1 Descent gradients/angles for charting. Descent gradients/angles for charting shall be promulgated to the
nearest one-tenth of a percent/degree. Descent gradients/angles shall originate at a point 15 m (50 ft) above the landing
runway threshold. For precision approaches different origination points may apply (see RDH in specific chapters).
Earth curvature is not considered in determining the descent gradient/angle.
5.5.2 Descent angles for database coding. Paragraph 5.5.1 applies with the exception that descent angles shall be
published to the nearest one-hundredth of a degree.
5.5.3 FAF altitude-procedure altitude/height. The descent path reaches a certain altitude at the FAF. In order to
avoid overshooting the descent path, the FAF published procedure altitude/height should be 15 m (50 ft) below this
altitude. The procedure altitude/height shall not be less than the OCA/H of the segment preceding the final approach
segment. See Figure I-4-5-6.
5.5.4 Both the procedure altitude/height and the minimum altitude for obstacle clearance shall be published. In no
case shall the procedure altitude/height be lower than the minimum altitude for obstacle clearance.
5.5.5 The designed stabilized descent path shall clear the step-down fix minimum obstacle clearance altitude.
This can be achieved by increasing the descent gradient by:
a) increasing the procedure altitude/height at the FAF; or (if a) is not possible)
b) moving the FAF toward the landing threshold.
5.5.6 Publication of OCA/H. An OCA and/or an OCH shall be published for each instrument approach and
circling procedure. For non-precision approach procedures, either value shall be expressed in 5-m or 10-ft increments
by rounding up as appropriate.
Aircraft categories
Table I-4-5-1. Rate of descent in the final
approach segment of a non-precision procedure with no FAF
Rate of descent
Minimum Maximum
Cat A/B 200 m/min (655 ft/min) 120 m/min (394 ft/min)
Cat H 230 m/min (755 ft/min) N/A
Cat C/D/E 305 m/min (1 000 ft/min) 180 m/min (590 ft/min)
23/11/06