The Hudson Helicopter Crash

[ctechbob]

Didn't hear about it until today. What absolutely heart wrenching footage. No signs of trouble until the very end, looks like the bird just came apart at the seams.

Juan seems to think gearbox lockup, seems to me that failed transmission mounts would do the same thing. Time will tell.

Yikes.

 

[mdtn952]

I saw this too...sounds like an instantaneous and catastrophic mechanical failure. LIke a very important component seized. Another high profile aviation tragedy...seems like there have been an increase in their numbers...I hope it is just a phase.. a brief phase.

 

[ctechbob]

..seems like there have been an increase in their numbers...I hope it is just a phase.. a brief phase.

I try to tell myself that it is just a side effect of living in the digital age where everything is recorded and everyone knows everything almost instantly. At least that's what I tell myself.

I guess I could dig up the data somewhere to see if it is happening more often or not.

 

[mdtn952]

Agreed...maybe I should have added, seems like there has been more of them, in a short period of time. Looking at data over a year it might appear different.

 

[wavinwayne]

We build helicopter simulators at work. I've been up close and personal to the actual helicopters multiple times, and am always amazed at how many things have to work perfectly right for things to not go horribly wrong.

 

[walterjay]

Sad. Just saw where a twin engine Cessna crashed in Florida killing 3.

 

[incognito_2u]

So sad to see this photo, taken less than an hour before their demise…..

 

[bdcardinal]

Looks like the gearbox/transmission separated with the rotor still attached, absolutely crazy.

 

[ctechbob]

Looks like the gearbox/transmission separated with the rotor still attached, absolutely crazy.

Indeed, seeing the pictures of the 4 dogbones that hold that assembly to the airframe...not that it seems like a break there would be easy, but a single failure looks like it would take out the whole assembly.

 

[2005jettatdi]

There is a reason why I never have and never will ride in a helicopter. On another site someone speculated on the blades flexing and striking the tail. This analysis show that could not have been what happened. Very sad to see a family wiped out in an instant.

 

[goblin]

Today would have been the middle one's 9th birthday, which apparently was what the trip was about. RIP.

As for number of occurrences - no. News just travel faster and further. The amount of accidents per flight hour have not increased. The number of hours could have though.

New York City has a helicopter death "rate" of about one full helicopter every five years in the last ten years, one the one before this one - because of sheer stupidity. A bit less before that (same number of accidents with more lucky passengers).

 

[I<3oil]

Reports coming out that pilot was a former Navy SEAL too

 

[awguy]

Things that go through the air grab far more media attention than things on the ground. Like the old old saying that says "if man were meant to fly..."

 

[incognito_2u]

Just asking those that are in the know: What is the “Jesus nut”, and what is its functionality on a Helicopter?

 

[bdcardinal]

Just asking those that are in the know: What is the “Jesus nut”, and what is its functionality on a Helicopter?

The nut that holds the rotor to the gearbox. If it comes loose, only Jesus can help you.

 

[Nukeman7]

Just asking those that are in the know: What is the “Jesus nut”, and what is its functionality on a Helicopter?

It is the large fastener that holds the rotor blades onto the rotating mast as shown below. It does not appear to be the failure point in the Hudson River crash as photos show the rotors were still attached to the swash plate when separated from the helicopter's fuselage.

 

[Cujet]

I believe the tail rotor or the tail boom visually failed first. Although this could be due to main transmission mount failure or similar and the transmission twisting around.

In the video at 5:37 in Juan's presentation, the helicopter seems to sharply yaw right, followed by in flight breakup. The tail sure seems to depart first, then the main rotor system. At 7:12 the main rotor is seen directly above the fuselage.

In more compete videos, the tail boom seems to be far behind the main rotor.

In any case, these transmissions are well attached, and known to be structurally able to handle about 6G's of force without damage. The heli is certified to (I believe) 3.5G, and the structural design limit is always 150% or more than the certification limit or about 5.25G. I am not at all sure the blades can, even briefly, generate more lift than that without stalling.

For that transmission and tailboom to come off so rapidly it is likely forms of weaknesses existed. Corrosion and fatigue always come to mind on a 20+ year old tour helicopter.

 

[Trav]

Just asking those that are in the know: What is the “Jesus nut”, and what is its functionality on a Helicopter?

I read about that nut this morning and yelled out to my wife " hey some lunatic holy roller crashed that helicopter". Honestly that was the only thing that came to mind, I must be really fried.

 

[repairman54]

At least this happened over the river and not over town on either side of the river.

 

[goblin]

At least this happened over the river and not over town on either side of the river.

That's where their flight plan is. Over the rivers only, around Manhattan.