View Full Version : Airbus FBW - triple clicks

28th Jun 2004, 14:59
Just seeking clarifcation of reasons for the triple click 'alert' to sound. My understanding is that it occurs on a downgrade from say cat 3 to cat 1. Some other text says that it also occurs when a new altitude is selected during ALT* and the ALT knob is not pushed or pulled.

Are these statements correct and are there any other causes?

Thanks in advance


28th Jun 2004, 16:21
You are both correct. The triple clicks or the cricket sounds:-
1) When the aircraft is first powered up & the FMGCs have completed their self tests
2) When there is a downgrade in the approach capability.

28th Jun 2004, 17:57

Depending on options and FMGC standard, triple click will sound;

- If "GPS PRIMARY LOST" during approach

- With CLB + NAV modes active, NAV mode is lost or disengaged (OP CLB engages).


28th Jun 2004, 20:04
The following sequences, or mode reversions, are highlighted by a triple click :

V/S selection in ALT*

SPD selection in SRS

CLB (or EXP CLB) to OP CLB, upon lateral crew action while climbing toward a constraint

ALT* to V/S, upon ALT target change

FD disengagement in OPEN modes

Alerting FMA display when V/S-(FPA) target is not held

CLB to OP CLB reversion, upon profile loss

Automatic FD re-engagement in basic mode

DES to V/S upon flight plan loss, or upon no lateral crew action

FINAL DES to V/S, upon NAV loss

Reversion to V/S when selected ALT crosses the current altitude

Automatic FD re-engagement in basic lateral mode

NAV to HDG, upon NAV loss


Condition(s) required for CAT3/CAT2 are no longer fulfilled.


plus a few others I guess !!!!!!!!!!!!

28th Jun 2004, 21:42
Thanks FlapsOne,

I got the impression it occured during reversions (at least with later software).