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Author Topic: Chistmas tree problem  (Read 3923 times)

Offline RD

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Chistmas tree problem
« on: 24/12/2011 23:08:26 »
  :o

are helicopters designed to shed their tail in an accident ?
« Last Edit: 24/12/2011 23:16:47 by RD »


 

Offline CliffordK

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Re: Chistmas tree problem
« Reply #1 on: 25/12/2011 04:28:17 »
Whew...
One wicked crash.

According to the reporters, he hit a cable, which ripped off one of the rotor blades.
That apparently thew the whole helicopter out of balance, causing the main engine to vibrate uncontrollably, and tore the helicopter apart.

The crash had a few things that apparently increased the survivability.

  • Low altitude.
  • Landing on the tail actually appeared to be a "gentle" landing.
  • There appeared to be a strong firewall between the engine and the cockpit.  So, when the engine broke free, it did not come forward.  I assume that is what caused the tail section to sheer.  I would just be thankful that the engine didn't fly forward.

As far as helicopter safety.
Have you heard of the Autogyro / Gyroplane?  Anyway, they fly with an unpowered rotor, just requiring forward thrust.

If a helicopter can maintain rotor revolutions, and forward motion, they may be able to land with an unpowered rotor.
 

Offline RD

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Re: Chistmas tree problem
« Reply #2 on: 25/12/2011 07:36:00 »
the engine broke free ... I assume that is what caused the tail section to sheer

I think you've got it. If part of drive shaft to the tail rotor got loose it would flail about. 
« Last Edit: 25/12/2011 07:46:16 by RD »
 

Offline SeanB

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Re: Chistmas tree problem
« Reply #3 on: 26/12/2011 19:22:18 »
He hit a cable, and broke off a rotor blade. Not good to have a very large unbalanced load on the main gearbox, which looks like it partially tore itself loose from the airframe, breaking the engine in half in doing so. The tail probably broke as the airframe overstressed the mountings, and luckily fell under the cabin as it fell. Too low for the pilot to do anything, and it dropped down right there. Nice showing that the fuel tanks are very well protected, in that they only leaked fuel onto the ground, and the engine ran on only for a second or two before the fuel in the lines ran out. Of course, being JetA1 it is really hard to get it to ignite. I think the airframe will be written off, and stripped for spares and scrapped. Sad it that those engines are so expensive to overhaul that they are routinely scrapped and replaced with new because of the cost of recertification. Just the cost of the qualified labour to test all the parts is too expensive.

Jay Leno does buy them second hand though, for his jet bikes. They are a very small 500kW plus power plant though.
 

Offline Geezer

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Re: Chistmas tree problem
« Reply #4 on: 26/12/2011 21:06:15 »
I found it interesting that the pilot wanted to get back to flying helicopters as soon as possible. I can understand why he would, but I couldn't understand why he thought anyone would let him fly one ever again.
 
Flying a helicopter when there is any possibility of a rotor whacking a cable is just expletive stupid. It's bad enough when it's in an attempt to save lives, but when it's to hang up bloody fairy lights.....give me a break!!!!!
 

Offline CliffordK

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Re: Chistmas tree problem
« Reply #5 on: 27/12/2011 04:04:06 »
I found it interesting that the pilot wanted to get back to flying helicopters as soon as possible. I can understand why he would, but I couldn't understand why he thought anyone would let him fly one ever again.

Perhaps he could find a future job as a test-pilot.

How does a chopper respond to a critical failure 20 feet above the ground?  But, then again, most similar tests would be run with a remote control system.
 

Offline Geezer

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Re: Chistmas tree problem
« Reply #6 on: 27/12/2011 05:10:30 »
Perhaps he could find a future job as a test-pilot.

I hear RR is hiring http://www.youtube.com/watch?v=f8W2SI4c93s
 

Offline SeanB

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Re: Chistmas tree problem
« Reply #7 on: 27/12/2011 16:59:04 »
So he will have to do some recertification tests, and a full medical. Then up in the air again. That is why there is so much training, to reduce accidents. The only way not to have accidents is not to fly at all. This was just one of those where the only damage was to repairables.
 

Offline Geezer

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Re: Chistmas tree problem
« Reply #8 on: 27/12/2011 18:38:43 »
So he will have to do some recertification tests, and a full medical. Then up in the air again. That is why there is so much training, to reduce accidents. The only way not to have accidents is not to fly at all. This was just one of those where the only damage was to repairables.

You've got to be kidding. It was a complete fluke that nobody on the ground was maimed or killed. He was negligent and reckless flying that close to any potential obstructions. If he'd ben driving a car or a truck, he'd get a hefty fine.

Don't the insurers have a say in it? I know what I would say if I was the insurer.

There is a case pending in the US where a coastguard helicopter flew into a power line. One of the pilots, who was supposed to be navigating,  survived. He has been charged with all sorts of bad things.
 

Offline CliffordK

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Re: Chistmas tree problem
« Reply #9 on: 27/12/2011 19:39:22 »
I'm a bit mixed on this.
He obviously had too tight of operating clearances with the job, and perhaps poorly marked wires and other dangers (I didn't see the one he supposedly clipped)

He should have had time to do a good site survey, and wait for favorable flight conditions, as this didn't appear to be an emergency response situation. 

Anyway, this seems to be a combination of poor planning and using the wrong tool for the job.  Accidents can happen.  Should the response be overly harsh?  Certainly the pilot learned from this.

The insurance company won't be happy with a quarter million dollar, or possibly much more, total loss on the helicopter, plus other damages.

Doing Christmas Lights may be very different than his day-job.  In fact, he may have been doing a job without proper training and practice.

Traffic Monitoring, or aerial photography may be at much lower risk.  Perhaps restrict his license to carrying crew members, but no passengers.
« Last Edit: 27/12/2011 19:41:04 by CliffordK »
 

Offline Geezer

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Re: Chistmas tree problem
« Reply #10 on: 27/12/2011 21:12:08 »
His reaction to the whole business struck me a very cavalier. In fairness, he could well have been in a state of shock, or at least he should have been.
 

Offline Mazurka

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Re: Chistmas tree problem
« Reply #11 on: 03/01/2012 12:12:08 »
I do not know what health and safety law is like in NZ, but if a proper risk assesment had been carried out, I would hope that it would have identified a safer way of doing the task.

However, we all learn from mistakes and even the best pilots can misjudge things. 
Following a brush with a cliff face on Pike o Stickle in Langdale  (whilst ferrying Kendal mountain rescue team members to a casualty on 17 May 2004) all Royal Navy SAR Sea King helicopters have one blade tip painted yellow to help the pilot judge where it is... 
Although the aircraft did an emergency landing in the valley, one rescue team member who was being winched down at the time of the incident was injured but subsequently made a full recovery.

(the slightly amusing end to the tale is that the RAF crash investigator got stuck and was rescued the next day)


 

Offline SeanB

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Re: Chistmas tree problem
« Reply #12 on: 03/01/2012 17:29:30 »
Often had pilots do an imitation of a brushcutter, especially in doing casevac in the dark. Memorable of the one used to burn that nice green cash crop, where we were pulling bits out of every cavity for months afterwards, as it was growing higher than the blades and they landed in the field.
 

Offline CliffordK

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Re: Chistmas tree problem
« Reply #13 on: 03/01/2012 22:01:00 »
Looking at the film, there are towers, and apparently wires everywhere.  I would have thought that a bucket crane would have been better than the helo.

Lights and identifiers on the wires, as well as rotor-tip lights/paint would have helped a lot. 

I'm surprised there was only one person in the cockpit.  I would have thought there would be one person dedicated to the load & spotting, and one person dedicated to flying.

Anyway, accidents do happen.  There is a lot to say for hindsight, and it is hard to know the entire situation for a brief film clip.  Hopefully the incident initiates a safety-review.  While nobody was seriously injured, it was close, and some very expensive equipment was destroyed.

I've been around construction enough to know that stupid things can happen, even with the best of planning.  I remember hearing about a dump truck running into a power line because it didn't get the bed lowered quick enough, or workers accidentally digging into underground wires that they had installed a few days earlier.
 

Offline RD

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Re: Chistmas tree problem
« Reply #14 on: 24/02/2012 18:02:28 »
another wobbly chopper ... https://www.youtube.com/watch?v=Cf1N70szHLg

allegedly "ground resonance" this time.
 

Offline Geezer

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Re: Chistmas tree problem
« Reply #15 on: 25/02/2012 19:15:48 »
Yes, wobbly choppers can be really nasty. Isn't there a gel you can put on them to prevent that?
 

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Re: Chistmas tree problem
« Reply #15 on: 25/02/2012 19:15:48 »

 

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