PPRuNe Forums - A320 Approach Autothrust

PPRuNe Forums (https://www.pprune.org/)

- Tech Log (https://www.pprune.org/tech-log-15/)

- - A320 Approach Autothrust (https://www.pprune.org/tech-log/562259-a320-approach-autothrust.html)

A320 Approach Autothrust

The FCOM describes below 3200' the autothrust becomes more responsive to speed variations.

My question is, during APP does the autopilot have a similar kind of logic which enhances its accuracy?

The only reference i can see is that it says in FINAL mode "Provides precise vertical guidance on the descent and final path with an internal vertical speed
limitation to avoid excessive V/S."

i don't have a "hard" reference in the manuals but the RA 1+2 FAULT description in the FCTM comes to my mind in a trice.

Quote:

Furthermore, the final stages of the approach should be flown using raw data in order to avoid possible excessive roll rates if LOC is still engaged. Indeed, as the autopilot gains are no longer updated with the radio altimeter signal, the AP/FD behaviour may be unsatisfactory when approaching the ground.

FCTM/AO-Abnormal Operations/AO 034-NAVIGATION/DUAL RADIO ALTIMETER FAILURE