A320 Auto Flight System: Speed Reference System Quiz

Revision Data Color

• Revision data appears in magenta on both MCDUs and NDs.

Actions on LAT REV Page

• Entries of NEXT WAY POINT, NEW DEST, or VIA GO TO on the LAT REV page result in a temporary flight plan (F-PLN) being created.

TMPY F-PLN Limitations

• A temporary F-PLN cannot be created if the primary flight plan is still active without revisions.

ACTIVATE SEC Prompt

• The ACTIVATE SEC prompt is available when selected with NAV mode engaged on the Flight Management and Guidance System (FMGS).

TEMP F-PLAN Page Display

• The TEMP F-PLAN page is triggered by changes made to the F-PLN or when a temporary change is initiated.

Creation of Temporary F-PLN

• A temporary F-PLN is created whenever a new waypoint is added or a revision is made to the current flight plan.

Managed Speed Profile Basis

• The managed speed profile is based on optimal performance calculations considering aircraft weight, altitude, and environmental conditions.

Required Mode for ACTIVATE SEC

• The FMGS must be in NAV mode to have the ACTIVATE SEC prompt available.

Function of 'AIRPORT' Key

• Pressing the 'AIRPORT' key retrieves specific airport data and information pertinent to the current flight.

Vertical Data Computation

• Once all vertical data has been defined, the Flight Management Guidance Computer (FMGC) computes the vertical flight profile and constraints.

Secondary Flight Plan Use

• The flight crew may utilize the SECONDARY flight plan for alternate routing or in case of deviations from the primary flight plan.

Temporary F-PLN Location Post-Revisions

• A temporary F-PLN is created and displayed on the active F-PLN screen after a revision.

Speed Limitation in SRS during Takeoff

• In SRS mode, speed is limited to the V2 speed when both engines are operating during takeoff.

SRS Speed Target on Engine Failure

• If an engine fails during takeoff in SRS mode, the speed target adjusts to the lower V2 speed for safety.

SRS Guidance Protection

• SRS guidance law includes protections such as speed protection, vertical speed protection, and angle of attack protection during flight.

SRS Activity Conditions

• The SRS is active during takeoff and continues until a safe altitude is reached or significant changes in flight conditions occur.

Maximum Nose-Up Attitude Reduction

• During takeoff in case of wind shear, the maximum nose-up attitude reduction by SRS guidance law is typically 7.5 degrees.

Display of SRS Guidance in Takeoff Mode

• SRS guidance is displayed in takeoff mode until the aircraft transitions to the climb mode post-takeoff.

Canceling HDG/TRK PRESET

• A pilot can cancel a HDG/TRK PRESET by selecting the 'CANCEL' option on the flight control unit (FCU).

RWY TRK Mode Engagement

• RWY TRK mode engages automatically during takeoff as soon as the aircraft starts its takeoff roll.

OP CLB Mode Engagement

• OP CLB mode engages after takeoff when the aircraft has achieved a safe climb altitude and speed.

Go-Around Below 100 Feet

• If a go-around is initiated below 100 feet, the system retains airspeed and altitude to ensure safe maneuverability.

Presetting Heading Before Takeoff

• To preset a heading of 210 degrees before takeoff, the pilot turns the heading selector to the desired value on the FCU.

Lateral Mode During Takeoff

• The lateral mode available during takeoff before lift-off is typically the lateral navigation (NAV) mode.

FMA Display in Managed DES Mode

• When descending in managed DES mode below profile, the Flight Mode Annunciator (FMA) displays indications of descent path deviation.

NAV Mode Loss Impact on DES

• If NAV mode is lost, the descent (DES) mode transitions to a heading-based descent (HDG) mode.

FMA Change from DES/NAV to OP DES/HDG

• FMA changes from DES/NAV to OP DES/HDG when lateral guidance is altered mid-descent due to navigation interruptions.

HDG Selection in THR IDLE/DES

• Selecting HDG while in THR IDLE / DES results in the flight director transferring control to follow the selected heading.

Conditions Above FCU Altitude in OP DES Mode

• If the aircraft is leveled above the FCU altitude with FD engaged in OP - DES mode and auto-throttle (ATHR) active, thrust is reduced to maintain altitude.

Managed DESCENT Above Profile Display

• During managed DESCENT if the aircraft is above profile, the FMA displays the current altitude as a cautionary indicator.

Test your knowledge on the Auto Flight System's Speed Reference System in the A320 aircraft. Mark the correct statements regarding the speed limitations and targets in different scenarios during takeoff and in SRS mode.