Must be getting old - pretty sure you’d have been sharper in the morning in Miri!

What is that damage in the tail area and what could cause the Floaters to not work?

https://cimg4.ibsrv.net/gimg/pprune....e4cc3ed997.png

Which model of float system was installed on the accident aircraft?

Must it not be activated until entry into the water but would self inflate if "Armed" by means of saltwater immersion switches?

The Cougar 91 Accident Report contains discussion re the various models of float systems and the procedures that pertain but that tragedy occurred some time ago and there might be differences today than noted in that report.

Perhaps someone familiar with the aircraft in question can address the workings of the Float System on this particular model or configuration of the accident aircraft.

Curious not just the workings of the float system but SOP on its use.

The 139 manufacturer SOP always got high marks from me for arming the floats whenever over water, regardless of speed. Some operators refused to follow that, arming only below a reduced speed.

ADSB looks like the power never came back in after the last level-off at 300' (coupled?)

If you droop the rotor, below a threshold, during a cushioning into the water, they will not auto deploy as some power requirements are now offline. Even if armed. So either, don't droop too low, or be aware of this and smash the manual deploy button upon entry.

Does that AD mean AW189s also need inspections before further flight?

GE CT7-2E1 engines

Float PWR is redundant and powered by both the #1 DC Primary Bus AND the Battery bus. So even if the RPM should drop so low (+- 80% Nr ) as to take the generators off line and the APU is not running. the system is still powered by the BATT BUS. The crew could also manually deploy the floats upon water contact, provided the system is armed, if they are unsure that the deployment system will function as advertised or the floats actually do not deploy automatically.

VNE floats armed is 80 Kts IAS. You get a caution light if you exceed 80 Kts with the floats armed followed by a nastygram weeks, if not months later from the FD monitors ( “You were the designated Captain and exceeded the VNE FLOATS Armed by 2 Kts! Do you care to comment????” A reply stating “ NO I do not care to comment. FYI I did, however, have the designated Co-pilot, who is a TRI, flogged upon return to base following quick Rotorhead Court Martial” worked very well. )

As regards “Different float Systems” The initial aircraft was equipped with “Sea State 5” floats which had 2 bags on the nose and one under the tail boom. later there was an upgrade to “Sea State 6” which added an additional float on each sponson. Arming and deployment SOP, Switches and manual deployment remained the same.
Looking at the photos you can see the aircraft had the “ Sea State 6” floats ( Panel aft and slightly below the panel with the word “Rescue”on the Stb. Sponson ) .

Other than a catastrophic power loss in the hover, one other possibility is an AFCS malfunction where the rad height didn't capture at the end of a TD. (or possibly finger trouble)

Mate only manual floats work on BATT power. The immersion switches won’t work only on the BATT.

Lots of good stuff there except I need to correct the one detail, on battery the floats do not auto deploy via immersion switches, even if armed.

Manual deployment required, which was my point.

From the ADSB it looks like altitude (rad alt) was captured, some power pulled in which sent the airspeed back to 100, then power back to slow down. What AP modes are coupled here? Who, how is the power controlled?

Reminds me of an Aberdeen 332L flying a scuddy non-precision to a beach airport that ended up in the water 10 years ago. Again curious on the training and SOP for the 92 in this situation, and if Bristow, CHC or even Cougar match up. We've spent over 20 years trying to figure out the best integration of autopilots in helicopters, it should be figured out now.

Autopilot likely is figured out. Weak point is usually the human interface.

What is the normal crew complement on the S92 for this role? It is tragic that anyone lost their life but I am wondering why so many people were onboard a training flight. Previous posts and media reports say that the victim was a nurse employed by Equinor. Is it routine for SAR training flights to carry supernumeraries onboard?

Just about the only piece of information from the NSIA so far on what happened, is that impact damage suggests that it came down in a pitch-down attitude.
The recorder has been transported to the UK for download.

Surely pitch down would damage the nose and flir mount? I see more rear damage?

AFAIK Pilot/co-pilot/winch op/winch man/flight nurse, 6th person possibly a rear crew trainer, no doubt in due course we will find out what the role of the 6th person was.

I was looking at a old training manual and could not find a warning that the immersion switches are not powered when on Batt. Power only. Do you have a reference I could use? Thanks for the info.
I did find a reference that if you are on the ground, floats armed and below 80% NR you will get a “Floats” warning caption…perhaps that is a warning that the immersion switches are no longer powered.
Interpreting Wiring Diagrams are very far from any of area of my supposed expertise. How a lightbulb works is a mystery to me.

I'll be interested to learn if the tail rotor was turning at the time of impact.

I would think the rotor disc has impacted the water and thrown the blades, severing the drive to the tail rotor before aircraft turns upside down and sinks? Explains why there is no MR but still an intact TR?