Flight Plan in Go Around
 Figure 009

 (2) Vertical F-PLN definition
 (a)
 Flight phases The flight plan is divided in several flight phases for which specific operations, prediction and guidance are defined. These flight phases are for ACTIVE primary F-Plan:

 -preflight,
 -takeoff (from origin to accel altitude),
 -climb (from accel alt to Top of climb),
 -cruise (from Top of climb to Top of descent),
 -descent (from Top of descent to Decel point),
 -approach (from Decel point to destination),
 -go around (missed approach points).
 -done.

 (b)
 Vertical flight plan elements (Ref. Fig. 010) The structure of a complete vertical flight plan is made up by different elements as follows :

 -
|  Thrust reduction altitude
 climb  |  Acceleration altitude
 |  Climb constraints
 |  Climb speed limit

 -
-| Constant Mach Segment (CMS) cruise | Cruise altitude (T/C - T/D) | Step climb or descent -
-| Descent constraints descent | Descent speed limit | Approach constraints -
-| Missed approach constraints missed approach | Thrust reduction altitude | Acceleration altitude -
If an alternate flight plan exists, the associated vertical flight plan is made up with the following elements :

 F-PLN Definition
 Figure 010

 -Alternate climb | Climb constraints | Speed limit -Alternate cruise Cruise altitude (T/C - T/D)
 -| Speed limit Alternate descent | Descent constraints | Approach constraints -
-Alternate missed approach | Missed approach constraints
 -
(c) Description of vertical flight plan elements
 1 Clearance altitude
_ It is derived from the FCU altitude. Upon modification of the FCU altitude :
 -
if the aircraft is not in level flight then the clearance altitude gets equal to the FCU altitude after a 2 second confirmation.

 -
if not, the clearance altitude is equal to the current aircraft altitude until the pilot pulls or pushes the altitude selector, at which time it gets equal to the FCU altitude.

 2 Thrust reduction altitude - acceleration altitude
_ (Ref. Fig. 011) The thrust reduction altitude is the altitude at which the pilot-selected takeoff thrust may be reduced to the climb thrust. The acceleration altitude is the altitude at which the aircraft begins accelerating towards its initial climb speed. For the engine out case, only an acceleration altitude (EO ACCEL ALT) is defined. Reference altitude. It is undefined until it can be calculated as follows :
 -
For takeoff: It is the origin waypoint elevation (if it exists). If not it is the aircraft altitude at transition to takeoff.

 -
For go around: It is the destination waypoint elevation (if defined).

 Perf Takeoff Page
 Figure 011

 3
_

 If the reference altitude is defined, the default values for thrust reduction and acceleration altitude are: Thrust reduction altitude = default thrust reduction altitude
 + reference altitude.
 Acceleration altitude = default acceleration altitude +
 reference altitude.
 Default thrust reduction and acceleration altitude are defined
 by each company in the fuel policy.

Constraints
 There are four types of constraints:

 -altitude
 -speed
 -time
 -Constant Mach Segment (CMS). Constraint may be entered and modified through F-PLN A page or through Vertical Revision page. (Ref. Fig. 012, 013) On F-PLN A page, the constraints (altitude, speed, time) are displayed with a star near the predicted value at the constrained point. If the constraint is predicted to be missed, the star is in amber color, else it is displayed in magenta color.
 a Altitude constraint:
_ It is an A/C altitude requirement to be met over a specified waypoint in the lateral flight plan.
 -It can be an AT, AT or BELOW, AT or ABOVE or altitude window constraint.
 -
An altitude constraint may be defined in Altitude or in

 Flight level. It is defined in Altitude below the departure transition altitude (in climb) or the arrival transition altitude (in descent). On the contrary, it is defined in Flight level.

 -
An altitude constraint is predicted missed if the aircraft cannot satisfy the constraint. In that case, the difference between the predicted altitude at the constrained waypoint and the altitude constraint value is displayed on Vertical Revision page. (If the difference is greater than 100 ft. or as long as it remains greater than 50 ft.). On flight plan page the star near the constraint is then in amber color. There are two types of constraint : climb and descent constraints defined as follows
　
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