Looking at an "enhanced" version of the full video posted above, the tailboom folded in the same plane as though the LH mount(s) failed. And with the 5 degree offset of the vert fin it seemed to follow that direction. Then everything else let go. Will be interesting to see the whats still attached to the tailboom. While there have been cases where a tailboom was lost it wasn't at speed like this one was. And since they have pics of where the components landed, I would think they would find them sooner than later. To me if he had felt anything in the drivetrain before that he would have been slowing down and looking for a spot to land which he had plenty in that area. Unfortunately it looks more like it was an instantaneous catastrophic event.

When bumping occurs, the main rotor shaft will be scratched or gouged. This is the weak point where the failure actually starts. Think about the tear-off receipts on your bills. The blades, head and rotors do not initially separate cleanly, they tilt over. This is when the rotors contact either the cabin or the tail. (The main rotor shaft has an impressive amount of twist when under load. This is why a small amount of damage can initiate a failure.)

But could that failing first cause the tail boom to fold like it did? It would certainly account for the MR separation but the boom went first.

But in the longer video it is clear that the break up starts before the MGB detaches, so that doesn't really match that theory - does it? Or maybe I misunderstood?

https://cimg4.ibsrv.net/gimg/pprune....58784bfa99.png
The MGB is still attached after the tail boom has detached

How would you manhandle a 206L to make the tailboom fold? Considering it appears to be in level flight and under power.
There’s rumour, then there is fantasy. With so many non aviation folks following a high interest topic, it is frankly irresponsible on a professional site (that comes ahead of the rumour in the title) to give credence to such unsubstantiated nonsense.

Fixed-wing FDM guy here - do those who do the work and fly them, (and who have my admiration), know what flight-data systems are installed on these types of operations?

I suspect, (and at least hope that), any such installation is going to be better than what we learned was “installed” in the helicopter involved in the DCA accident, but I am not familiar with the FARs, nor the CARs here in Canada that govern CVRs & DFDRs, etc. for rotary-wing aircraft.

There was a recent incident with a 206L with Van Horn blades that got into the “van horn nodal beam hop” so bad that it crinkled the tailboom on the way down. Curious if the helicopter was light enough for the same but the vibes got bad enough to break the tailboom and/or rip the tranny out?

I don't think this aircraft will have any recording devices fitted, but I assume it will have a GPS unit of some kind (Garmin?) which will contain a certain amount of data, in a non-volatile memory, to help analyse the flight path. It is not inconceivable that one or more of the pax may have been filming on their phones, at the time of the incident, which will obviously also be very valuable.

For what it's worth, I notice on the NTSB youtube channel that they will hold a media briefing at 18:30 GMT today.

Don't know if I am allowed to post links yet, let me try:

If the upper LH tailboom mount bolt or fitting failed in flight, the air loads on the vertical fin will fold the tailboom to the right at the same time the nose of the aircraft spins right into the tailboom. No manhandle required.

Several years ago a similar failure happened to a 407 in Hawaii with 6 on board, at 1500ft with 130 indicated when there was a violent upset and the nose spun right. A pax saw something fall from the aircraft and by hook or crook and luck they all survived. The tailboom had departed the aircraft in a similar fashion due to the upper LH T/B bolt failed. Unfortunately with the L4, I know of no teetering head helicopter that could survive such a CG upset in flight and stay together.
Hawaii 407 NTSB

I posted this some years ago, but feel that it bears some significance to the subject matter of this thread.

Getting Back on the Horse

I was a relatively low-time PPL-SEL (maybe 200 hours) in 1979 when a friend who was flying Evergreen 206 LR's to a test oil rig off the coast of Georgia said he would teach me to fly "frantic palm trees". I had accumulated four hours and could hover clumsily but handle other flight regimes satisfactorily when he called one Sunday morning to ask if I'd like to bring my wife and 9-year-old son on a sight-seeing tour. Hell yes, I would!

We flew for an hour doing some low-level (10’) high-speed passes over the marshes, rivers, and ocean, and some fairly high G aerobatic work. We were three minutes from KSSI (McKinnon St. Simons) and were on long final. We had received permission to land and were descending through 2,000'. My "friend", a 6,000-hour 'Nam pilot who was flying right seat, came over the intercom and said "Watch this!" He reached for and cycled the Emergency Fuel Cutoff switch. The annunciator panel went from green to orange to red! He had starved the engine of fuel and we were too low to get a restart! This was going to be a genuine autorotation. I turned to my family in the rear seat and yelled "Brace! Brace! Brace!"

We hit the beach, the skids dug in, the helicopter tipped forward, the main rotor clipped the tail boom off in a neat decapitation which spun us a full 360 degrees. My wife grabbed our son in her arms and exited to the left; the end of still-spinning main rotor puffed up her hair as it cleared her by an inch! I fumbled with my 5-point restraint for what seemed like hours, then ran like the devil.

The starboard fuel bladder had ruptured and was spilling jet-A near the exhaust. The T.O.T. was ~ 700 degrees, the VSI pegged at 2,500 down, and the ASI at 40 knots. We were lucky to be alive...

Some serious adult beverage consumption coupled with general prayers of thanksgiving to anyone listening followed that afternoon, but bright and early the next morning I went alone for an hour's introspective solo in my 152. Had I not, I am not certain that I would have ever flown again.

I have abseiled and was an ardent skydiver until my then-wife put her foot down and forced me to choose between her and my T-28. I have hung by one foot and one hand 50' above the stage while changing gels and bulbs in theatrical lighting. But get me on a 6' step ladder and it's time for vertigo and acrophobia! Go figure...

- Ed

I would like to revisit the fuel starvation scenario. Back in the 1980s our unit had a similar inflight breakup of a Bell AH-1S. I was determined that the cause may have been the result of an inadvertent rollback of the engine at high speed and max power. This resulted in the rotor extreme main rotor flapping causing it to contact the airframe in multiple places as it departed the aircraft. It concerns me that the pilot request fuel within 3 minutes of takeoff into what would have been a relatively short flight.

Are we all in agreement that if you lose Tail Rotor drive, for whatever reason with power applied the Bell Helicopter will enthusiastically yaw RIGHT?

It would, perhaps , be quite normal to advise ops that you would need fuel after your flight when you are busy and perhaps there is one pad designated for fuelling or the(y have to advise a fueler. I know not what the normal procedure is for this operator. In any case the investigation should reveal whether the low level warning light and/or boost pump lights were on.

If I remember correctly (Nick Lappos will), that was something fairly unique about the Cobra. In the event of an engine failure at high speed, you were well advised to delay lowering the collective as you normally would because that resulted in excessive rotor flapping.The correct response was "Whut?" and then remembering not to do that right away.

A Blancolirio report.
I think he says that this Bell is not common for Mast Bumping

Yeah. Hence the question mark in my reply to post #60.
EDIT:
If somebody has some insight that yaw was to the left then the main gear box has suddenly seized. Sudden gearbox seizure and the helicopter is going to follow the rotation of the main rotor and things will get instantly violent and inflight breakup will most certainly occur, including loss of the tail boom and main rotor system. I can't be certain from the video if it was yaw left or right. I'm not aware of a 206 main gearbox ever seizing suddenly in flight with no prior warning to the pilot.

This was the pilot, an ex Navy Seal according to New York Post.
https://nypost.com/2025/04/11/us-new...-sean-johnson/

https://cimg1.ibsrv.net/gimg/pprune....862a8482d.jpeg

RIP, brother... :(

wrench1: I assume you are referring to an 'enhanced' version of the video posted on Reddit? Is that an enhancement you made? If so, are you able to share some screen shots to illustrate? Seems to me it would be difficult to enhance something so apparently low resolution to start with?

In #97 Obba posted a link to a Juan Browne review of the accident and at 6:10 he is of the opinion that the main rotor with its gearbox parted first, but that differs to what most here interpret as what happened, namely that the tail rotor and part of tail boom separated first. That is how I also interpret the various videos when considered together. But many components, including cowlings, must have separated from the main fuselage on the way down, so hard to say what is actually seen in the footage.

An enhanced version of the photo from the NY Post article. Original photo Christopher Sadowski

https://cimg7.ibsrv.net/gimg/pprune....e38086e3ea.jpg

"IF" fuel was critically low, wouldn't the pilot elect to land at that jetty when the fuselage crashed, or opt to inflate the skid fitted float bags, and just land safely on the water or the jetty? (maybe experienced pilots could comment)

If referring to the full length version where it shows the aircraft in level flight prior to the break up the yes. But it was done by a friend of which I have no copy. The sequence I noted was the tailboom folding to the right at the same time the nose rotates right then everything goes south. At least thats my interpretation.

Fuel is a red herring. It has nothing to do with what happened here.

The critical thing is how long the MGB stayed attached after something broke, if that was the start of the inflight breakup sequence. If the link broke and shunted the MGB out of alignment, it's feasible those forces could have resulted in a sufficient yaw rate to snap off the tail boom when suddenly faced with 80kts of cross wind. Once the tail boom departed the scene the already compromised MGB mounts failed entirely under additional loads and the MGB with rotors still attached departed the scene.

Some reports imply that he flew helicopters in the Navy, but I'm pretty sure he was an enlisted man, not a Naval Aviator. One report says he learned to fly at Embry Riddle. Someone claiming to be his shipmate says he served with him on an aircraft carrier as a Gunners Mate.
I wonder if he was a Gunners Mate attached (at some time or another) to a support unit in support of a SEAL team or if he actually graduated from BUDS training.

He was a Navy SEAL. His last job prior to moving to NYC was as a co-pilot with a friend of mine Earl on a CH47 for Billings. He moved to NYC to further his aviation career. Sad to see this.

Was up shooting some air to air today in a 407 here in Florida and have to say kept thinking back to what happened in NY the other day and for the first time in a long time I had the nerves going. Even at 500ft high its still a long way down. May they Rest in Peace. :(

One photo of him appeared to be as he sat in the right hand seat of a Blackhawk....might that have been taken during his time in Montana?

There are numerous photos of him at the Billings Face Book page including one of him flying a Chinook during the firefighting season.

This talk of the fuel call being a disguised mayday is fanciful at best. He called for fuel as he no doubt needed fuel, probably like he would do 10 times or more per day! Presumably to get the fuel guy/gal out at the pad ready to hot-fuel, saving time and money.

Kulwin Park: If you took the time to see my above post, you would see that Fuel WOULD NOT HAVE BEEN AN ISSUE...
It simply appears that the pilot requested that he might need re-fueling on landing, as one assumes he had another flight.

Considering the StrechedBanger was made from the 70's through to around 2017, with thousands made, and an enormous amount of flight hours, it is a proven platform.
There is no indication what actually happened nor the root cause. It is not used for scheduled passenger services, nor can it carry hundreds of people, which authorities tend to treat with much greater caution.

You could speculate that one of the mounts failed, as was made further up in this discussion.
If that were the case, there have been 3 previous accidents, all which survived, two landed in one piece, one rolled over, and were ultimately attributed to inadequate maintenance.
They all involved partial loss of control, and reports of the nose pitching up and a roll to the left.

On such a mature type, It is highly unlikely that this an inherent flaw, or something previously undiscovered.

"It is not used for scheduled passenger services"

Oddly enough, it has been, in what was then the largest helicopter network, between Glasgow and various destinations in the west of Scotland, including Fort William, Oban, Rothesay, etc. with a list of exemptions as long as your arm. It was a safe machine then and it is now - this I feel is a one-off, like the incidents with the 212 and TT straps. As bell ringer says, it is a proven platform and I believe it was at one time (if not still) the safest single engined aircraft, based on hours flown.

You’d need to ask yourself, which is more likely?

1. Tail boom folds and subsequently the main gearbox disconnects

2, The main gearbox disconnected and the tail boom folded

Some will assume, because it is the first thing we see, that the tailboom failure was the cause. However, it's what we can't see that matters.
My feeling is that the tail folding was secondary to the transmission, or mountings, letting go.

(But if you are a follower of British tabloids, it was definitely the Jesus nut) :suspect:

There were a couple of heli’s collided years ago and can be seen on those YouTube shorts where the main rotors collide and the first thing that happens is that the fuselage turns 90 degrees and the tail boom snaps straight off.

What I’m wondering is if it was a catastrophic transmission failure, would the blades keep spinning for an auto rotation, as once the blades and transmission left the fuselage, they were freely rotating with the transmission hanging below, so the transmission wasn’t seized? It’s not possible surely that the blades AND transmission were spinning through the air is it? (Thinking of a child’s toy here)

What about the engine, quite often in these events, something let’s go and the engine rpm goes through the roof; does anyone hear an engine in any of the videos? Mike Pateys turbine Lancair went from cruise RPM to zero in about a second, I fully expected that to at least tear the engine off the mounts or at least some torsional damage, but seemingly nothing.

A case, (re post 80 above)…
https://asn.flightsafety.org/wikibase/188940

If the MRGB is allowed to move (as a result of one of the nodal beams or other fixings giving way), it would twist the TR drive out put which could, feasibly, create enough imbalance and drag along the TRD shaft to overstress the boom and cause it to fail.

What is puzzling is that it looks like the rotors take only the top part of the MRGB with them when they separate rather than ripping the whole gearbox out.

Whatever the initial trigger, it rapidly becomes a catastrophic in flight breakup which even the best pilot in the world wouldn't survive.

Ah, I already knew the theoretical answer, it’s just everyone keeps saying otherwise. My first post theorised the same.

Squawk7000 - I guess this is the paragraph you are referring to in that report So a slipping freewheel suddenly biting again could generate the forces required to make the tail boom fail.

Re-introducing two components turning at different speeds when they are designed to drive at the same speeds is a recipe for disaster - see the Wessex crash in the Welsh lake back in the early 90s - that was a disconnect coupling allowing the TR to slow down and then taking up the drive again as the yaw input was changed.