VicMel, what you write does not match the FDR data on AOA values that were shown in the interim report of the Lion Air accident.
It doesn't fit how SIN/COS resolvers work either.
There is a good analysis of what type of resolver, mechanical or electronic failure could match such an almost constant 22° offset on the site of Peter Lemme.
It is worth a read. It's here:
https://www.satcom.guru/2018/12/angl...ure-modes.html
I made a quick check of what would produce a constant 34% positive parasite signal on the sinus entry combined with a 16% negative parasite signal on the cosinus entry.
It gives the series (in degrees)
Real Angle - Reported Angle - Delta
-2 19.97512 21.97512
-1 21.00953 22.00953
0 22.03623 22.03623
1 23.05537 22.05537
2 24.06711 22.06711
3 25.0716 22.0716
4 26.06899 22.06899
5 27.05944 22.05944
6 28.04309 22.04309
7 29.02008 22.02008
8 29.99056 21.99056
I have no idea on what could cause such parasite signals.
Could be inductive from a 400Hz current (like the excitation current), or could be a DC parasite signal in the entry of the analog to digital converter.
Don't misunderstand me ; I do not state that this is what caused the AOA failure.
Just looking at failures that give similar symptoms.