Thanks ND - also, do you know if hot fluid is the only time an EP permits closing the main 1(2) SOV ?

Yes, understood. That bit is clearly shown in the bulletin Figures.

In spite of the football, it was still a good explanation!

Not quite, but thanks again for your answer. I'm just interested in evolution/progression of Augusta design logic.

Have not seen any updates on investigation. Wondering if I missed something posted elsewhere.
Not sure when updates would be expected.
thanks

​​​​​​Still under investigation no new updates from the aaib since October, not even been changed to finalizing, they must be struggling with something in my opinion.

WuW

I suspect that Covid 19 hasn’t helped with the speed of their investigations.

Perhaps they are just baffled by how a heavily regulated supposedly ultra safe Cat A take off profile with all those engines can still manage to crash and burn...

Perhaps you are right chop, I have followed you for awhile, I can't help but think this is one rare instance that hindsight quick thinking thought processes couldn't of turned this pilot into a hero :(, I try to stay in the background on this forum, this thread gets to me, RIP to all involved.

WuW

Is this not the one where the tail rotor bearing failed resulting in the tail rotor not rotating anymore? What went wrong is known. The causal chain is not (yet public).

Exactly. Having a well supported private aircraft kill everyone on board during a routine takeoff does not inspire confidence.
Evidently there was no obvious design defect, so the investigators are now clutching at straws.

Your ‘Evidently’ interests me. What evidence are you referring to?

​​​​​I believe TR did not lose rpm but went full pitch. The chain of how that happened is all in this thread.

They could be clutching at straws struggling to try work out how a simple component (duplex bearing) can fail in away that's not been seen before and lead to such a catastrophic loss of control and what could be done to prevent it again. Just a opinion :ok:

WuW

No, it was a tail rotor control failure. The tail rotor continued turning but the blades ran to full negative pitch, which is worse than a failed tail rotor drive.

poor maintenance procedures will get you whatever other protections you put in place.

let’s see if this component was ever touched after it left the factory - pretty low hours I think.

Well, none of the above should take anything like as long as the enormously expensive AAIB are taking. And I invite those who think, unhesitatingly, to defend the organisation, to pause for once and consider the facts.

That leaves you with poor design or incorrect installation - nothing you can do as a pilot will affect those.

Monty N

Slightly naive comment, as it is not just the technical members of the AAIB who determine when a report is released. I can think of delayed reports in the past where it has not been the AAIB or the investigation that were the problem, it was the lawyers for the party who appears to be "at fault" and thereby facing financial and reputational consequences, who then tried every avenue to "water down" the report findings before publication.

This particular airframe was one of the first in production, and it had reasonable use. One might therefore expect any issues in design, original build or maintenance scheduling to become apparent on an airframe like this. The information released so far indicates that a duplex bearing in the tail rotor control control mechanism failed and AW issued a service bulletin requiring this part to be checked in all 169 & 189 back in 2018. I guess that both AW and the AAIB know the result of that check, but to my knowledge that result has not been published. It would be interesting to hear from any owner or mechanic who can say what this check found.