It’s my understanding that the planetary reduction gear is located towards the top of the 206 main rotor gearbox. A sudden stoppage of this planetary gear assembly ( as in the Super Puma a few years back ) might potentially bust out of the gearbox casing and split it in two.

In a 206, the transmission is not directly connected to the t/r driveshaft - it runs through the freewheeling unit and then the engine. To me, it appears that not only did the entire transmission come out, but maybe the engine as well! Look at this pic and tell me what's missing. That lump there towards the back - is that the engine or just the oil cooler?
https://cimg0.ibsrv.net/gimg/pprune....087ff20e53.jpg

This is interesting about the freewheel on 206's https://www.casa.gov.au/sites/defaul...separation.pdf

So a freewheel failure/snatch could have caused the TRDshaft to distort stressing the tail boom as well as trashing the MRGB.

FWIW: word is the MR, transmission, and nodal beam assembly departed together still attached to the roof/deck section.

The transmission on a Bell 206 is held in by 2 x upside down V links

https://images.proxibid.com/AuctionI...5043/151-2.jpg

These have broken before - as in this incident in Australia https://www.atsb.gov.au/media/news-i...e-requirements

https://www.atsb.gov.au/sites/defaul...?itok=PUBkzyQG

This has been referenced previously. In this case the bearings had worn which accelerated fatigue, there had been inadequate inspections.

The two V links are on the non-nodal beam equipped 206B. The 206L has four independent links between the transmission and the two nodal beam flexures.

Sea level , 6 lightly dressed pax, no baggage, probably max 400 lbs of fuel if planning 4 tours between fuelling.
I doubt you would be anywhere near 100% torque on departure much less pulling any transients.
Certainly not cruising around at max continuous Q.

We have decided to ground our Longranger pending further information coming from the NTSB ,FAA ,CASA and Bell

Worth being conservative in this case I reckon!

I do not believe it will be a very long time before the relevant information is available that will allow safe flight

Exactly right, completely normal call for those types of ops.

Photo from the NTSB showing rear of the aircraft, and separation of the tail-boom aft of the attachment points.

https://cimg3.ibsrv.net/gimg/pprune....91cea2ae9d.jpg

That also looks like what is left of the hot section and exhaust of the engine.

Further Photos (NTSB):

https://cimg3.ibsrv.net/gimg/pprune....fcd05213de.jpg

https://cimg5.ibsrv.net/gimg/pprune....bef964353c.jpg

In other words, not a case of the four boom attachment bolts having been the cause of the accident.

Zooming in, what appears to be the remains of the engine and aux gearbox.

https://cimg9.ibsrv.net/gimg/pprune....3e5c27174d.png

Well clearly if they are still attached, no.

https://cimg3.ibsrv.net/gimg/pprune....3579ef9b11.png

1. Vertical with tail-rotor(?)
2. Tail boom
3. Main rotor
4. Cabin


https://abcnews.go.com/US/tourist-he...y?id=120755978

Watch ABC News video at 1:18 and note that main rotor separation occurs a lot later than tail boom and tail rotor.
That would seem to indicate that the tail boom failed first after extreme and rapid yaw.

You can see the T/R Driveshaft section is broken about halfway, ENGINE to OIL COOLER FAN section, just above the white Starter Generator in the above picture.

That has been stated previously in this topic.
What is impossible to tell from the few pixels contained in these videos and related images, are what caused the extreme yaw.
Was it something in the tail rotor drive system that went, or, was it something in the main gearbox, transmission or mountings that let go first.
That is nothing the currently available videos can answer, beyond confirming a sequence of visible events.

What @Bell_ringer said. I agree.

According to the NYT

So there was an extreme and rapid jaw. What about a passenger in front that accidentally pushes a rudder pedal? Or are the pedals removed in sightseeing flights?

I can’t imagine the dual controls would be installed for operations of this nature. The tail rotor pedals might remain in the aircraft but with the links secured to non-moving pins so they just become footrests for a front seat passenger. The collective is still between the front seats but likely guarded closely by the PIC.

Would companies that do this kind of work have cameras installed (Appereo Vision 1000 etc) like we do in our USFS contract aircraft?

This news story sadly shows one of the little girls sat next to the pilot. I'd be surprised if she could reach or over power the pilot on the controls.

https://nypost.com/2025/04/11/us-new...-sean-johnson/

It's been depressing in the UK to see how this has been reported in some outlets (both jounalists and commenters).

Focus was initially all about possible mechanical failure - until the pilot's picture was published.
Focus was then on questioning his qualifications, experience, even DEI ...
Then when it was reported that he was an ex-Seal - they went quiet ...
Now questioning of whetehr was actually an ex-Seal or a "real Seal"

The reporting about the pilot has been in complete contrast to the reporting about the family that died ...

I understand the "human interest" angle but a lot of the reporting has been exploitative of the family - and disrespectful to the pilot

I've always found the aviation community to be generally resistant to press/industry tendencuies to blame pilots before investigations are complete (Boeing?)

Seemingly rather less so in this case? ...

RIP to all

That’s disgraceful. Those scrotes surely wouldn’t have had the courage to ask those questions to his face if they had the opportunity. Once the investigation comes out and if he is found to be not at fault hopefully his family sues for defamation.

Main Rotors
 

It is said that the Main Rotors have not been recovered yet. Are they likely to sink to the bottom of the river, or would they float, because of honneycomb construction..?
There is a video of the helicopter splashing down, and a further splash 100 yards further into the river, one second later. So this is where the NTSB Divers need to look.

edit... I have just seen Blancolirios post, and it is clear the rotor blades were still attached to their gearbox, when it entered the water.

Recovering the transmission will be critical to the investigation. I imagine that the blades themselves would be "low density" because of the honeycomb construction, but the grips, head, mast and transmission would certainly be heavy enough to sink the assembly.

Had an event on a Bell 412 where it lost the tail rotor and t/r gearbox in flight over the Gulf (no injuries). An extensive search was conducted for the missing assembly with no luck, so Bell took another similar assembly with an added pinger and dropped it in the area. Turns out the assembly was only slightly negatively buoyant. The assembly was track drifting along the bottom in the current. The incident hardware was never recovered.

Fingers crossed this is not the case here.

Yes. The boom failed at the 1st bulkhead aft of the mount rings where the bolts are.

I see the MR controls mixer and the engine installation but nothing of the nodal beam transmission mounting system, or even the roof deck the nodal beam is attached to. Did the rotor and transmission just rip itself off the aircraft and take the roof with it? That's an extremely violent set of loads to cause that. Loads this violent could also fail the tail boom if it was the same source of loads that contributed to both structural failures with the boom failing first, then the roof structure.

https://cimg0.ibsrv.net/gimg/pprune....b5ea2a6b5c.jpg

Is the nodal beams stronger than their hardware attaching them to the fuselage? Is that hardware ever been known to fatigue?

Spline Drive: Just a thought on the mounting locations of the transmission to the airframe as I ponder what you posted.

There are multiple mounting points. If only one failed initially, might the loads initiated by the first mounting point letting go be of sufficient magnitude to created a dynamic torque effect on the tail (hence the fold) and then as that restraint was lost the other mounting points let go sequentially, and then rotor head and transmission departed the aircraft? I don't think that "all of the mounting points let go at once" fits what I see on the film clips that I've reviewed so far.

(The ABC news link at 1:18 from a post further up shows the helicopter straight and level before the building blocks the view...not sure if anything visible happened between then and the helicopter re-appearing in the camera's field of view).

As I look at the film I get the idea in my head that it all happened so quickly that the pilot may not have had time to get the collective down (startle effect being a known phenomenon) before it all went horribly wrong.

Thanks. Were any attach points broken?

For crab: thanks for the info on the freewheeling unit.

Or perhaps the other way around. I was involved in the investigation of a [not Bell] crash, where the tail rotor had a failure first, and the resulting vibration was enough that the tailboom departed the main fuselage. In that case, the remainder of the helicopter hit the ground before more parts departed, but the forces were extreme on the main fuselage after the tailboom departed. Perhaps, on the Bell, such forces could be sufficient to rip the top deck/transmission attach points off.

Scary thing is, if it was the Van Horn bounce, putting the collective down only makes things worse. The info letter put out about it less than a month ago says the harmonic is the same natural frequency as the tailboom.

Van Horn 206L MRB IL

Pictures I've seen of a suspected VH bounce that got on the ground has severe damage in the same area of the tailboom that was the break point on the New York machine.

What difference would getting the collective down have made to an aircraft without a tailboom, and soon thereafter, no rotor system?
I can only hope that as interest wanes in this accident, the quality of discussion improves.

Did this ship even have van Horn components?

If it were a newer aircraft in the beginning of it's production run, I would agree. But after almost 50 years of production and millions of hours on these machines, probably an overreaction.

In a general sense, if you reduce the collective pitch you reduce the need for antitorque since the engines were still on and generating torque/power.

But yes, given how soon (hence my point on the startle factor) the main transmission left the aircraft, that consideration became moot very quickly.
And if the main transmission's mounts failed first (and the tail fold was an artifact of that, see my initial reply to Spline Drive) then it was certainly moot before that.

For TwinHueyMan: thank you for the paper on the Van Horn bounce. :ok:

Looking at the NTSB pics its looks like the attach points are all intact and you can see the upper RH bolt as well. The tailboom failed right behind the intercoastal support structure which provides the load path from the mount ring hardware to the monocoque structure of the tailboom.