akaSylvia
which should not be about whether or not he is culpable but how it was allowed to happen and how to stop it happening again.
An AAIB investigation and a police investigation have different objectives.
The AAIB's objective relates to flight safety.
Hebog
Your summary of the position is broadly correct.
Two points:
(Car crash) ..... witness statements are all provided to the CPS.
Police take witness statements and provide them to the CPS.
There is nothing to prevent the police from taking statements from witnesses while an air accident investigation is being conducted by the AAIB.
I would imagine that the AAIB may not be able to issue their report until the CPS have decided if they will be taking any further action and then possibly after any resulting court case.
The AAIB does not have to wait, and does not do so.
It is concerned only with the flight safety aspects and issues final reports as soon as it is in a position to do so.