I have noticed an ATSB "Preliminary report" has been released today related to this Super Puma loss, but it seems to be more an update of the summary of what ATSB has been looking into rather than providing much detail:

https://www.atsb.gov.au/publications...rt/ao-2024-060

What does seem clear is that the focus of attention is on the tail rotor, consistent with what has been indicated in earlier posts here.

I realise this is entirely speculative, but I have been wondering what impact those large bubble windows on the cockpit doors might have had on the flow into the tail rotor? many helicopters (especially military) already have plenty of appendages that would disrupt the smooth flow of air along the fuselage, but these windows take that to the next level. Might the tail rotor have been experiencing a significantly larger fluctuation in inflowing air and consequently have experienced greater cyclic loading than had been anticipated for the original design? Or will this sad loss be explained by something far more straightforward?

Update: The actual preliminary report was uploaded to the site after this post.

The windows will have an STC and that would have involved flight testing. In any case, the distance from the windows to the tail is about 14m and any airflow turbulence will dissipate following a cube law, so I very much doubt any relevance. You should look at what the TR experiences from the MR - that’s a huge amount of turbulent airflow energy.

Would the paperwork for such an STC go so far as examining flow and loads, or be more a case of test flights to confirm handing remains acceptable?

But yes, I see your points. The MR should also direct any poor wake off those bubbles downwards and so away from the high mounted TR.

As a 332 engineer of lots and lots of years. It's well known that the shimming of the tail rotor bearing end cap is critical as it pre loads the bearing. Get the shimming wrong and you've got problems. SB's and AD's cover this.

I've done a few flight test programs for Puma variant bubble windows and they were all limited to comparative handling, stability and control, and performance, so with normal and bubble windows back to back. Never any discernible difference with the bubble windows installed.

What on earth are people banging on about bubble windows for, these machines fly around with liferafts, big sponsors, small sponsors, missiles, flir cameras, and all manner of bolt on goodies attached to the external surfaces ,so please keep to facts not fantasy.

The question was asked by a non-pilot enthusiast. He was afforded a polite reply.

Selemat, if you read my message you would see I was well aware of the things that already hang off helicopters and I emphasised military helicopters.
I may only be an enthusiast when it comes to helicopters, but I have a reasonable understanding of fatigue life and how sensitive it can be to incorrect characterisation of the loading cycles.
I have also seen a case of significant vibration in a non aviation context as a result of modest appendages that were fitted by an OEM oblivious to the consequences they would have.
But I will give it a rest now.

It's a long time ago - must be around 1979 - but we hung a huge early Hele-Tele on the side of a Bo105 for Metropolitan Police work. It was installed the same side as the tail rotor. I seem to remember that the flight tests resulted in a VNE restriction of 105kts otherwise no problem.

https://cimg0.ibsrv.net/gimg/pprune....1b88e72f39.jpg
The Army had it installed on their Lynx in NI as well:

https://cimg5.ibsrv.net/gimg/pprune....b5aee57d1e.jpg

Way back in the late 70s I recall Transport Canada coming to do some air tests on the S61 for the LH bubble window, not a 100% sure but I think they put an airspeed restriction on at that time.

I do know that on any ferry flights we replaced them with the standard windows.

A few years later we got a contract in Asia with a company to train their pilots for long line operations, we had a 332 with bubble windows installed on both cockpit doors, and they had a VNE restriction, think that may have been a company one though.

Back in the day the windows were large and cumbersome, I would say the modern ones are a lot more streamlined.

A post on a parallel thread related to this accident in "The Pacific:..." forum made it apparent there is now a more detailed preliminary report available from the ATSB:

https://www.atsb.gov.au/publications/investigation_reports/2025/report/ao-2024-060

It reports a fatigue fracture of the sliding sleeve supporting the tail rotor pitch change control plate.

While the control rod running inside the sleeve was also fractured, the report doesn't discuss the nature of its fracture.