Systems Guide

A318/A319/A320/A321
Professional
SYSTEMS
Systems guide
Vol
4
04-03-12
11 July 2018
FLIGHT PHASES
The FMGC divides the complete flight into phases that normally will automatically switch to the next
phase when certain conditions are met.
Flight Phase
Optimum Speed Profile
Switching conditions to next phase
Preflight
-
SRS take off mode engaged +
N1 > 85% or Ground Speed > 90 kts
Take Off
V
2
followed by V
2
+10
At ACC ALT (or manually)
Climb
ECON CLB SPD/MACH
At reaching Cruise Flight Level
Cruise
ECON CRZ MACH
At reaching ToD
Descent
ECON DES MACH/SPD
Overflying Decel waypoint with NAV (or LOC/LOC*) engaged
Manually activating APPR phase
Approach
VAPP (GS Min)
To Go Around: thrust levers to TOGA
To Done: automatic 30 seconds after landing
To Climb: inserting new CRZ FL
Go Around
VAPP or Current Speed
To Approach: manually select APPR phase
To Climb: manually select CLMB phase
Done
At depressing INIT or PERF to Preflight
PERFORMANCE
The FMGC will minimize the flight cost through speed optimization. Depending on the Cost Index setting it
will compute optimal targets for the following items:
• Take off, approach and go around speed are calculated as a function of the TOW and
performance model. Note that V1, V2 and Vr must be manually entered (in our aircraft these
speeds are calculated but can be overwritten.
• CLB and DES speeds are computed as a function of the GW, Cost Index, environment
(temperature, wind) and Cruise level. The speeds are NOT recalculated when the mode is active.
• Cruise Mach is computed as the optimal speed and is updated continuously update to the
current weather condition and F-PLN modifications.
• Optimum Flight Level is calculated assuming a 5-minute minimum cruise flight. It is continuously
update in flight.
AUTOPILOTS
ENGAGEMENT
The autopilot (two identical systems) are engaged by the AP1 and AP2 pb on the FCU. When engaged a
green bar will show on the pb and the appropriate FMA annunciation is displayed. When a flight director
is on when the autopilot is engaged, the autopilot engages in appropriate mode (OP CLMB and NAV)
otherwise it will engage in the default guidance modes (HDG and V/S or TRK-FPA).
Either autopilot can be engaged seconds after takeoff.
DISENGAGEMENT
Disengage the autopilot by depressing the AP1 or AP1 button.
• The autopilot is automatically disengaged by moving the side stick (or rudder pedals) a certain
amount. This will trigger a master warning.