Strictly, I don't know why it was deemed necessary to have the Review as well as the Inquest. However, the scope of the Review is clearly different to the Inquest so we can take a pretty good guess. The ToRs for the Review are:
In light of the board of inquiry report:
· To examine the arrangements for assuring the airworthiness and safe operation of the Nimrod MR2 in the period from its introduction in 1979 to the accident on 2 September 2006, including hazard analysis, the safety case compiled in 2005, maintenance arrangements, and responses to any earlier incidents which might have highlighted the risk and led to corrective action;
· To assess where responsibility lies for any failures and what lessons are to be learned;
· To assess more broadly the process for compiling safety cases, taking account of best practice in the civilian and military world;
· And to make recommendations to the Secretary of State as soon as practicable, if necessary by way of interim report.
The first two bullets focus on Nimrod and thus will overlap with the Inquest significantly. I believe that the third bullet, though somewhat vague, indicates that the scope of the Review covers MoD's approach to Safety Cases in general and not just for the Nimrod. (I suppose it's conceivable that the scope of the third bullet may end up being confined to aircraft Safety Cases, to make it practicable.)