Hi CONF iture,
1-
HN39 had already
pondered one of your
previous post :
Quote:
Originally Posted by
A33Zab
so AOA#1 could be effected, however didn't had any influence.
FCPC using median AOA (or outvoted AOA#1), AoAsw using highest AOA value.
2- There is no such thing as a "FCPC outvote an AoA"
If one AoA sensor is stuck, there is a possibility that its own ADR
anemometric value will be rejected.
Now, remember that in the meantime, was taking place an ADR anemometric values rejection process based on
pitot unreliable informations.
Thx for recalling this post, I did reply on that one but at the same time
the forum was 'under maintenance' and I forgot later on.
Each Aoa vane drives 3 identical resolvers, 1 remain unused.
(may drive AoA indicator in future?)
Due to pin programming the other 2 can be used as averaging value or
- as pin programmed in the A330 - 1 is active and the other used as
backup in case of failure of the active resolver.
Resolvers sin and cos are AoAi input for the ADIRU.
ADIRU calculates the AoAc from the AoAi to compensate for position
errors (identical AoA sensors used for all 3 positions) and S/F config.
(BTW: the vanes are dampened by eddy current, no oil based damper is used)
Each ADIRU sends his AoAi (LBL 221) and AoAc (LBL 241) values in ARINC 429 format to all FCPCs.
In normal operation the FCPC uses the median value of the 3 AoA values
BUT if an AoA signal deviates a predetermined value(?) from the median
the FCPC will reject this AoA signal (for remainder of the flight) and will
use the average value of the #1 & #2 sensor.
If the difference between AoA#1 or AoA#2 and the median value from all
three ADIRUs is higher than a set value(?), the FCPCs use a memorized
last valid average value for a period of 1.2s.
After 1.2s the current value is then used.
The FCPC uses the AoA value for the protections(limits) in NORMAL LAW.
In ALTERNATE LAW those AoA protections are not available anymore and
FCPC can do without any AoA signal.
They salvaged 800VU rack(FCPC2/3), separate mounted FCPC#1 and AoA sensors.
After investgation of those components they will surely respond to that,
but you are right! they could have made a comment already in the
footnote about this AoA#1 sensor.