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Old 27th Jun 2011, 15:35
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A33Zab
 
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HN39:

A33Zab;

Your "Chronology of events @ 5 sec interval." has a column headed "STALL AoA". I presume that is 'alpha-max', which is not stall AoA but somewhat less. Alphamax varies with Mach number as shown on a graph posted a few days ago. For the Mach numbers in your table:

Mach ... alphamax

0.8 ......... 5.2
0.68 ........ 7.1
0.64 ........ 7.7
0.59 ........ 8.1
Actually, I used the AOA Stall warning trigger values.

Mach threshold ... AOAsw (I did edit this in the chronlogy diagram)
0.82 .................... 3.8
0.75 .................... 5.2
0.53 .................... 7.6
0.35 .................... 9.9
<=0.28............... 10.8

BEA Report 2:

In alternate or direct law, the angle-of-attack protections are no longer available
but a stall warning is triggered when the greatest of the valid angle-of-attack values exceeds a certain threshold.
In clean configuration, this threshold depends,in particular, on the Mach
value in such a way that it decreases when the Mach increases.
It is the highest of the valid Mach values that is used to determine the threshold.
If none of the three Mach values is valid, a Mach value close to zero is
used.
For example, it is of the order of 10° at Mach 0.3 and of 4° at Mach 0.8.


I've added your values in a separate Alpha max column.
A33Zab is offline