Quote:
Originally Posted by
CONF iture 
Now, if it's normal by conception to autotrim under stall warning, it is aberration.
Dozy
This is a serious question, I promise I'm not being facetious here... Why do you consider it an aberration?
I agree with CONFiture in this regard.
The Bus has little to restrict it from autotrimming nose up in Alt2, beyond the stall AOA, and I believe this is a potentially dangerous characteristic.
I recognize the Airbus is Certificated now under EASA CS-25.
If you look at comparable language in FAA AC 25-7B, Flight Test Guide for Certification of Transport Category Airplanes
http://www.airweb.faa.gov/Regulatory...FILE/25-7B.pdf
(3) Procedures.
(a) The airplane should be trimmed for hands-off flight at a speed 13 percent to 30
percent above the anticipated VSR, with the engines at idle and the airplane in the configuration
for which the stall speed is being determined. Then, using only the primary longitudinal control
for speed reduction, maintain a constant deceleration (entry rate) until the airplane is stalled, as
defined in § 25.201(d) and paragraph 29c(1) of this AC. Following the stall, engine thrust may
be used as desired to expedite recovery.
Here is an aircraft being stalled for certification purposes while trimmed at a speed 13 to 30% above VSR. Now do you really want to give an automatic system the ability to trim to a higher trim value than the aircraft has been certified for?
A trim setting tells an aircraft to hold a certain AOA. To allow the trim to run up after stall warning says, "Lets increase the AOA some more." This reduces the aircraft's natural tendency to drop its nose in the stall.
If AOA for stall indication doesn't work in ALT2 because the Mach stall AOA correction cannot be calculated without a known good ADR, then they had better figure out another method of stopping the trim from autotrimming nose up after reaching VSW.