A320 Autopilot Pitch Envelope

[Bula]

G'day All,

Just a couple of A320 questions for the Technically savy A320 dirver among us.

1. When the AP is engaged it is allowed a 1.3g limit (and from what i understand) this is 1.4g in expedite mode.

Approaching high speed protection @ VMax the high speed protection pitches up and reduces side stick authority to maintain Vmax, with O/SPEED triggering at VMax + 4. Does the AP have a authority of 1.3g + 0.75g or 1.4 + 0.75g or 2/2.5g prior to being disconnected with the highspeed protection at > VMax

2. In expedite climb with during light windshear the airspeed begins reducing towards Vls.

At what point does the Autopilot increase its authority to ensure a pitch down to maintain speed if the trend continues to reduce. The FCOM from what I can see makes no specific reference to the specific G authority of the Autopilot. Does anyone have a reference?

[Bula]

wow...... I can hear the echo

[aulglarse]

BULAaah BULAaaah BULAaaah,

Question (1),In supp techniques FCOM 3.04.27 p9, there is a section on overspeed in terms of automatic A/P disengagement and a 1.75G pull-up in ADDITION to pilot input.

Some serial numbers do display a "G LOAD" at the bottom of the SD.

Reversion scenarios in FCOM 1.22.30 p39 and p42with FD's ON when FD's auto disengage without A/P respectively, while p45 has a mode reversion summary. No mention of "G" limits.

In which section did you find these "G" additives?

Question (2), I cannot find any reference in regards to your query of "G" authority/logic and airspeed trend towards VLS. Only that the speed trend arrow usually gives you 10 seconds at the current rate of closure on what speed will be reached which you may know of.

From experience using Expedite mode, a sudden change of wind from head to tail or a rapidly increasing tailwind will feel a more pronounced negative "G" as the speed trend arrow decays to or even below VLS.

I'm sure other posters may have some more info.

[Bula]

Reading an incident report on an overspeed in the UK spoke about the 1.75g pull additive be a "trend" towards Vmax. Just wondering if this applies to Vls. Had a real positive push in that exact situation though I cant seem to find anything to cover it.


we shall wait and see