Helicopter crash New York City

[wrench1]

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.

[CLUTTER]

Originally Posted by albatross

Sorry Clutter. What is a stress riser? Are you referring to bending forces being applied to the mast by the rotor head and blades.

Isn’t it the blades and head flapping excessively, especially in a low or -G situation causing. the bump stops on the head to impact the mast causing it to deform, lose strength and break.
Hence occurrences of mast bumping in nap or the earth flying when the aircraft comes over a ridge line and the pilot abruptly moves the cyclic forward and perhaps even decreases collective pitch to follow the terrain. Low or even negative G, low power, rotor system flapping…the holes in the swiss cheese line up quickly.
I vaguely remember being told the G limits were -0.5 G to +2G and to especially avoid low or -G to avoid bumping.

An amazing amount of non-helicopter folks think the mast is a solid steel rod not a cylinder.

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.)

[[email protected]]

Originally Posted by gulliBell

This is the part they will be looking for. If the link assembly of the nodal beam system breaks you are in a spot of bother.

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.

[212man]

Originally Posted by gulliBell

Yep. My guess is your guess is on the money. They will unravel what happened soon enough.

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?


The MGB is still attached after the tail boom has detached

[Bell_ringer]

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.

[PJ2]

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.

[TwinHueyMan]

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?

[212man]

Originally Posted by PJ2

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.

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.

[hanche]

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:

You Tube

[wrench1]

Originally Posted by Bell_ringer

How would you manhandle a 206L to make the tailboom fold? Considering it appears to be in level flight and under power.

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

[cavuman1]

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

[Jack Carson]

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.

[albatross]

Originally Posted by gulliBell

When you are humming along at 80-100kts and there is a sudden loss of drive to the trail rotor that does not result in a massive uncontrollable yaw. In forward flight you have a lot of vertical hardware hanging off the206L tail boom to give you some directional control. Lower the collective lever to reduce the torque in the rotor system and you're back in business with a fighting chance. Yaw to the left with loss of drive to the tail rotor in the 206?

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?

[albatross]

Originally Posted by Jack Carson

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.

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.

[Tailspin Turtle]

Originally Posted by Jack Carson

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.

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.

[Obba]

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

Bell 206L Crash Hudson River New York - YouTube

[gulliBell]

Originally Posted by albatross

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?

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.

[TowerDog]

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

[twinstar_ca]

RIP, brother...

[helispotter]

Originally Posted by wrench1

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...

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.