Helicopter crash Hudson River 1

[LittleInch]

Helicopter sight seeing inner York crashed with all dead.

This video looks like it was flying at some speed, then something happens, it seems to change orientation very rapidly which causes the whole tail structure to detach, followed shortly by the main rotor blade and part of the gearbox. Horrible way to go.

https://www.reddit.com/r/CatastrophicFailure/comments/1jwfxh9/full_video_of_the_helicopter_crash_in_hudson

Six people killed after helicopter crashes into Hudson River in New York

Pilot and a family with three children who are believed to have been Spanish tourists were killed onboard aircraft

www.theguardian.com

 

[TugboatEng]

I don't think a boom strike would cause the mounting deck for the transmission to separate from the air frame.

 

[Sym P. le]

It appears to be a clean torsional failure.

I don't see any torsional component to the tail failure. It looks like a clean break to the right and slightly down, given the break line along the row of rivets. I don't know if a driveline seizure could whip the aircraft around so fast that the tail couldn't follow but that's what it seems like to me.

 

[LittleInch]

The helicopter goes sideways at over 100 knots for reasons they might never work out in less than one second so not a lot of surprise the tail snapped.

 

[Tomfh]

I think the tail will show signs of being hit by the rotor. The rotor was probably already damaged, maybe from mast bumping or something else that broke, and wasn’t properly held in place. It likely hit the tail, which then broke off. With the helicopter further imbalanced by the loss of the tail, the already weakened rotor eventually came off too.

 

[mfgenggear]

Wow if o

is a zoomed in version https://streamable.com/56ttmc

Looks like something very dramatic happened which caused the helicopter to yaw and spin violently to the right which caused the break up of the tail.

The money seeks to be on main gearbox failure and hence may have weakened the gearbox which then broke off along with the main rotors.

So possibly if the main gearbox jammed and the motor flung the helicopter round before it probably broke something. Once the tail went there was no getting it back.

If one looks closely , seconds after the boom breaks , can see the main rotor turning , then second later the entire mast Flys off.

 

[mfgenggear]

I don't see any torsional component to the tail failure. It looks like a clean break to the right and slightly down, given the break line along the row of rivets. I don't know if a driveline seizure could whip the aircraft around so fast that the tail couldn't follow but that's what it seems like to me.

View attachment 8336

What posted earlier, look at tail rotor shaft.
It appears just snapped. Thete is no visual of bending. Axial moment. It's spinning at 6k rpm.
The shaft sponing inside at 6k rpm would do damage. OK I took a closer at but it could be bent. But it also looks elongated?

 

[Sym P. le]

The tail rotor shaft sits atop the tail structure, enclosed in its own shroud. The two inner members I believe are vertical and horizontal stabilizer linkages. I think they were just pinched as the tail snapped off.

 

[Sym P. le]

Wow if o

My animated gifs are here (long) and here (short slo-mo) They are an interesting study in video editing. The source video is not continuous. The file size is controlled by algorithms leaving out "redundant" frames and substituting duplicates (or many more) of other frames to make up the lost time. For fast moving events such as when the helicopter yaws, we can't be certain that we are getting the full picture (so to speak). As I reviewed the streamable this time, it finally dawned on me what is happening. The helicopter doesn't merely do a 90 degree yaw and stop (that's not physically possible), rather it does a full 360 or 720 degree spin before the tail departs. Incredible and true! This catastrophic failure is extremely violent.

Furthermore, if a news channel (or other) picks up the original and transposes it to a different frame rate or any other optimizations, you can get movement artifacts such as the wiggle seen in the slo-mo gif. That movement is not true (it's not in the original video) and should be ignored.

 

[mfgenggear]

My animated gifs are here (long) and here (short slo-mo) They are an interesting study in video editing. The source video is not continuous. The file size is controlled by algorithms leaving out "redundant" frames and substituting duplicates (or many more) of other frames to make up the lost time. For fast moving events such as when the helicopter yaws, we can't be certain that we are getting the full picture (so to speak). As I reviewed the streamable this time, it finally dawned on me what is happening. The helicopter doesn't merely do a 90 degree yaw and stop (that's not physically possible), rather it does a full 360 or 720 degree spin before the tail departs. Incredible and true! This catastrophic failure is extremely violent.

Furthermore, if a news channel picks up the original and transposes it to a different frame rate or any other optimizations, you can get movement artifacts such as the wiggle seen in the slo-mo gif. That movement is not true (it's not in the original video) and should be ignored.

It appears the helicopter Lost rotor function.
Then boom failed, then mast flew off.

 

[XR250]

It appears the helicopter Lost rotor function.
Then boom failed, then mast flew off.

Near the end of this new video, Juan gives his analysis..

 

[Sym P. le]

It appears the helicopter Lost rotor function.

The yaw isn't so much a loss of tail rotor function, it's that when the drive train seizes, the inertia of the lifting blades instantly spins the aircraft in the opposite direction with sufficient force that the tail rotor can't counter even if it were still functional.

 

[Sym P. le]

Here's the frame which was ripped out of the fuselage.

 

[Garbage1]

Or was fuselage thrown away from engine mount?

 

[Sym P. le]

The rotor went its own way, discarding dreams of harmony. I'll never make it as a wordsmith, but then, was it Lennon that channeled cauliflower?

 

[mfgenggear]

Wait for NTSB results

 

[waross]

Three schools of thought.
1. Boom strike first.
2. Rotor left the helicopter first.
3. (Sym P. le) "Wait for NTSB results"

If the rotor was damaged in a boom strike, centrifugal force may have kept the blades extended straight as they fell.
"Wait for NTSB results"

Do I have any expertise in helicopters?
Not really.
But I did drink a lot of coffee with a pilot who survived a hard landing when a boom strike completely destroyed his helicopter.
In his accident, the force of the strike caused the helicopter to roll over on the ground.
He did not mention if it also rotated horizontally at the same time.

 

[XR250]

Me thinks catastrophic gearbox or engine failure. Caused a hard yaw which broke the boom and also ripped the mounts from the body.

 

[Sym P. le]

A hard landing can cause a boom strike as can a narrow set of in flight conditions, none of which make it a go to theory as an initiator for this incident. I don't need to wait for a certified gov report before I start to familiarize myself with publically available information and I hope others don't hide away from it either. It does get tiresome listening to some trying to sqeeze all of the info through their pet theories and popular dialogue.

 

[waross]

It does get tiresome listening to some trying to sqeeze all of the info through their pet theories

Found this picture this morning. I know nothing about helicopters, but I did hear a lot about 'mast bumping' when it first happened. Does this picture suggest that both rotors are broken at about the same length by contacting the tail boom?

The position of the rotor damage relative to the distance to the tail damage will settle this for me.
Hence.
Waiting for the report.

 

[TugboatEng]

The wait for the report crowd are a bunch of wet blankets. This kind of speculation is healthy provided we remain open minded about our assumptions.