Originally Posted by
DaveReidUK
I don't think they did.
I'm pretty sure you are correct. There is an IOU to EASA (and perhaps others) to provide a 'synthetic' AOA that can be used to validate the mechanical AOA sensors (basically a 3rd source to allow voting if there is a disagree). However given the difficulty in developing and certifying the associated s/w, there was an agreed to timeframe before the synthetic AOA s/w needs to be certified and retrofit. I don't remember what that timeframe was though.