Copyright D.P. Browne 2011

Arming

Engagement

Disengagement

Guidance

Vertical Speed / Flight Path Angle

This mode acquires and holds the selected FCU Vertical Speed (V/S) or Flight Path Angle (FPA). The HDG V/S - TRK FPA push button on the FCU may be used to select between V/S and FPA modes.

There is no arming criteria for this mode. It is selected by the flight crew directly using the FCU.

The flight crew may select the V/S or FPA mode by either :

Pull the FCU V/S knob

Engaging F/D or A/P in the air, when no A/P or F/D was previously engaged.  

Select a different altitude on the FCU, when in ALT * mode

Select a higher altitude on the FCU when in DES, OP DES, EXP DES

Select a Lower altitude on the FCU when in CLB, OP CLB, EXP CLB

The V/S or FPA mode will automatically engage if :

5 sec after lift off and no other vertical mode exists

Upon loss of G/S or G/S * mode

Upon loss of FINAL

Upon loss of vertical flight mode in DES

The flight crew may deselect the V/S or FPA mode by either :

Puling or pushing the altitude selector knob

Pressing the EXPED button on the FCU

Selecting another vertical mode

The V/S or FPA mode is disengage automatically if

ALT * mode engages

Go-around mode is engaged.

The V/S or FPA guidance has priority over the aircraft’s speed control. If too much V/S or FPA is targeted, then the Auto thrust may not have sufficient authority to control the aircraft’s speed.

Only when the aircraft’s speed reaches the upper or lower limits, does the V/S or FPA target automatically change to maintain that limit. When this happens the Automatic speed protection in the V/S or FPA mode engages.

HDG V/S

Vertical Speed mode

TRK FPA

Flight Path Angle mode