(b)
Type II is a next course capture between two fix referenced legs (which are not connected) or from a heading/course leg (VX or CX legs) to a fix referenced leg. (Ref. Fig. 020) Substitution of a type II transition for a type I transition can also occur under the following conditions:
-an overfly has been specified for the active leg
-a turn direction is specified for the next leg which causes course change of greater than 180 deg. (except for PX, AF, HX)
Type I Transition CF, TF
Figure 019
Type II Transition
Figure 020
-course change between active and next leg is less than or equal to 3 deg. or more than or equal to 175 deg.
-distance between the termination of the active leg and the path of the next leg is greater than 1 NM. The type II transition captures the path of the next leg by using the fixed path control law. A type II transition is used to capture the parallel offset path. When the parallel offset is cancelled, a type II is used again to capture the original flight plan. (Ref. Fig. 021) Transitions to holding patterns are also type II transitions. There are three types of entries:
-direct entry
-teardrop entry
-parallel entry The type is determined by the region from which the aircraft crosses the holding pattern fix. (Ref. Fig. 022)
1_ Direct entry
The aircraft captures either turn number 1 or outbound leg
using a type II transition.
(Ref. Fig. 023)
2_ Teardrop entry
The aircraft captures a 30 deg. intercept course from the
holding pattern fix and holds this course until the distance
from the holding fix is equal to 2.56 times the radius of the
circular arc of the holding pattern (fixed path control law).
Then, the aircraft performs a circular arc (turn control law)
(constant turn radius, course change = 180 deg.) before
capturing the inbound leg using a type II transition.
(Ref. Fig. 024)
3_ Parallel entry
The aircraft captures a parallel course to the inbound course
using a type II transition (fixed path control law). Then, it
initiates a circular arc (constant turn radius, course change
= 180 deg.) (turn control law) before capturing the inbound
leg following a type II transition.
(Ref. Fig. 025)
(c) Type III is a transition onto a heading leg (VX legs). In that case, a capture is performed to the desired heading. (Ref. Fig. 026)
Parallel Offset Capture
Figure 021
Transitions to Holding Pattern: Determination of Entry Type
Figure 022
Direct Entry
Figure 023
Teardrop Entry
Figure 024
Parallel Entry
Figure 025
Type III Transitoin CF-VA
Figure 026
(d)
Type IV is a transition onto a direct type leg (DF). A circular arc path is used to capture the great circle course of a DF leg. This type of transition is also used to capture a fix referenced leg from a VI or CI leg. (Ref. Fig. 027)
(e)
Type V is a transition onto course legs that are not fix referenced (CA, CD, CR legs). (Ref. Fig. 027) Transition types are given in the table of leg transition types (Ref. Fig. 028)
NOTE : (for the figure)
____ -The IF is part of the next leg. No transition exists.
-NAV is disengaged in discontinuity. No transition exists.
-Both legs must have the same radius. No transition exists.
-The NEXT leg is converted to a DF leg if the conditional altitude is met, otherwise, the transition is as if no condition existed.
(3) Use and display To define a path the active, next, third and fourth legs are checked to determine the required transitions. Based on the path definition, the FMGC produces the leg geometry and the active leg path geometry. The ACT LEG PATH GEOMETRY is used for controlling the aircraft and consists of the active leg, the next leg and the transition between them. The LEG GEOMETRY is used in generating the EIS F-PLN display. In all cases, it consists of the active leg, next leg and transition between them. However, if the transition between the next leg and the third leg is a type III or type V, then the third leg and transition onto it are also displayed. Moreover, if the transition between the third and fourth legs is a type III or type V, then the fourth leg and transition onto it are also displayed.
Type IV and Type V Transitions
Figure 027
Leg Transition Types 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：A320飞机维护手册 AMM AUTO FLIGHT 自动飞行3(89)
