Pitts, while I am no EC advocate, I will suggest to you that it is in EC's interests to get to the bottom of this because they face a non trivial customer confidence problem. Their investigation, which will doubtless aid and abet the AIBB's efforts, has to be thorough and right or they don't solve their problem. As I see it, not solving their problem hurts them in the millions of dollars in revenue, or maybe tens of millions.
They are incentivized to get it right, and to show AIBB and the various regulating agencies how right they really are.
Totally agree and of course they have resource and a need to get it right, but then isn't that the case with any manufacturer suffering a hull loss from mechanical failure?
EC have clearly being briefing customers given the comments from Bristow last week and indeed on their own "Aberdeen" part of EC website - in fact they have made 2 such posts since the last AAIB interim report.
Its an interesting dynamic where the manufacturer is the one that tests and gives its findings to the investigating body. For the sake of rigour of process one would expect it to be driven by the AAIB (in this case) especially since EC have been shown to be lacking in many areas in this one.
If EC are able to suggest that 225's will be flying with additional restrictions come the Spring then it suggests that they know what the problems are, which are so far unreported by the AAIB.
Hence the tail wagging the dog comment.
Edited to add: the purpose of course for the AAIB to come to conclusion is exactly for the reason to stop the same accidents from happening again i.e. you loose an aircraft in May and again in October.