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PHOENIX "rescue" No thanks!

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PHOENIX "rescue" No thanks!

Old 6th Jun 2019, 09:49
  #21 (permalink)  
 
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SLMFS - providing there are no obstacles to affect the safety of the aircraft, descending whilst winching out would get the patient to the ground quicker and have the small added benefit of reducing the downwash slightly - the primary aim would be to get the stretcher down within reach of the ground party asap.
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Old 6th Jun 2019, 09:52
  #22 (permalink)  
 
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Handy g calculators here and here. Rather her than me.
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Old 6th Jun 2019, 19:43
  #23 (permalink)  
 
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I get an acceleration equal to 5.04g. a = 4(pi^2)r/(T^2)=4(3.14^2)(0.8)/(0.8^2) = 49.35 m/s^2, convert to g by dividing by 9.8 = 5.04g. That is probably unconscious in the absence of experience or a strain maneuver.
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Old 6th Jun 2019, 21:39
  #24 (permalink)  
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At the patients age of 75 years, sustained 5+ g loading, they are so lucky this didn't result in a death.
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Old 7th Jun 2019, 00:08
  #25 (permalink)  
 
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That sure ain't the way to do that kind of work.

Unless I am grossly missing something....there should have been a suitable landing area (no matter how small) somewhere close by that the aircraft could have landed.

I would sure like to hear a first hand account of how all this transpired....especially with the source having had time to think over it all.
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Old 7th Jun 2019, 00:52
  #26 (permalink)  
 
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Originally Posted by SLFMS View Post
Serious question Crab, why get the helicopter to descend? I'm experienced in winching operations and did not consider than an option. I'm interested to know why you think it is?
The winch out goes without saying.
To add to [email protected] reply, we were taught to descend when winching in once the bodies on the hoist were about 10ft above the surface, to maintain that height for them as a maximum for them to fall should anything go tits-up. With the move to larger machines with auto-hover/height hold this went by the board as downwash also became an issue plus accurate auto height hold.

There seem to be more and more videos of winch jobs where an unnecessarily high hover is maintained during and after the lift. A very good friend had never been taught about this, and when the crewman and 'survivor' fell from an excessive height onto the deck of the training vessel, both were killed. A transit to over water along with a lower height would have saved them both. Those of you engaged in winchops may like to review the height used by their operation with this in mind.

Re the spin and going to a lower height in this instance: the pilot held a very high hover for ages, with associated power requirement. A descent would have reduced that power and associated downwash, allowing the stretcher to be brought into the cabin without encountering the downwash problem so evidently apparent in this video.
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Old 7th Jun 2019, 11:30
  #27 (permalink)  
 
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Horrifying to watch!
One surely hopes they were using a tag line and sadly it failed. To not have a tag line attached is inconceivable.
So many questions around this event.
- did they use a tag line (hi-line)
- if so to above did the weak link fail prior to spin commencement (if it failed why?)
- was there air to ground comms
- was there some form of hoist (winch) malfunction
- crew training issue
- SOPs in place to deal with a situation like this (winching out)

it appears in the video on the first attempt to bring the stretcher in once the spin began he did winch out and the spin did slow somewhat. But why in hll did he try again? Appears to be a small road directly in front of the AC, why not rest it there till some other solution was discussed. On the second attempt to winch in the HO must have seen the spin developing again but yet continued (??) To a point that was critical. It looks like he did winch out somewhat and as the video ends the AC had began to translate.
Hoisting ALWAYS last option. But unfortunately mostly only one at times.
Personally had a scary training exercise at night somewhat similar (but larger AC) Hoisting in a empty (though weighted litter) with all crew on goggles as the litter was approaching the sill a rapid and violent spin began. We had a tag line attached but was beyond the capabilities of the rescue man on the ground to control it. The onset was so quick and violent that there was a brief second of confusion bewteen all crew.
The litter ended up contacting the underbelly, sponson and unbelievable directlying behind the PF's window. No crewmember had ever seen such a rapid onset. The cable was immediately winched out and we regained control. We never encountered a similar situation after but became more vigilant then ever.
sometimes sh!t just happen sadly enough.


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Old 7th Jun 2019, 22:58
  #28 (permalink)  
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Wonder if there's footage of 5 minutes before the start of this posted footage? @fox10phoenix
That would be very interesting.
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Old 8th Jun 2019, 12:58
  #29 (permalink)  
 
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Originally Posted by [email protected] View Post
SLMFS - providing there are no obstacles to affect the safety of the aircraft, descending whilst winching out would get the patient to the ground quicker and have the small added benefit of reducing the downwash slightly - the primary aim would be to get the stretcher down within reach of the ground party asap.

Thanks Crab, understanding the intention is to get to the ground sooner makes sense. The only counter argument could be that remaining higher means there will be more cable out and the stretcher will be less effected by the down wash. I understand your point though. See the point below for John but normally when I winch its at the lowest safe height for the operation. This doesn't really leave any significant room to descend over land but judging from the video it looks like they had plenty.


John Eacott thanks for your reply also. I agree with your points about excessive winch height. Watching the video my first thought was why are they so high? I do try to not judge though as camera angles can change the perspective or the crew may have had a good reason for winching high that we are not aware of. Generally speaking I have noticed on many videos that the winch can be very high. I prefer to be lower where the references make hovering easier, the winch time is minimised as well as the exposure for the operation. Some may argue to winch higher for OEI options but while that needs to be considered but I do not think this can be done in isolation.
Winching also needs to be done with intelligent reasoning. I once had a disagreement with a new Crewman that wanted to move during ship winch from the very large bridge wings of a massive container ship back and left over the water. When I explained that due to the size, stability and clear zones of the vessel we could remain over the wing where the winch height was about 15ft rather than move back and left over a 150ft drop to the ocean. His answer was that the operations manual stated that was the procedure. It took quite a bit of reasoning that while normally that would be the best option in this case it wasn't so we were not going to do it and be slave to a procedure. He did come around in the end when we agreed that a 15ft drop to a steel deck was bad but a 150ft drop to the ocean would surely be fatal. The aircraft safety was the first priority and the aircraft was not jeopardised to achieve this, it ended up been a very simple and easy winch.
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Old 8th Jun 2019, 17:17
  #30 (permalink)  
 
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In regards to the spinning of the Litter we have suspended operations in my unit until a new procedure is put in place. Our new helo has a considerable amount of rotor downwash and really moves a person or litter around depending on the hover height and wind strength. Even using the guideline attached to our litter, it was still hard to control just about the time it came to the bottom of the aircraft and would cause damage to both aircraft and litter.
As for arm chair quarterbacking, I have been doing this for a number of years and personally would of lowered the litter to the ground, depending on the suitability of the surface. Definitely a good crew debrief was had post flight to address the issue and learn from it. Thumbs up to the person in the litter, came away with no further injuries is amazing considering the spin
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Old 8th Jun 2019, 17:32
  #31 (permalink)  
 
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No further injuries indeed. Here is a quote from her husband who was with her. You don't endure that many g's without injury. I'll bet there are broken capillaries in her feet as well.

vto Mac and Gaydos of KTAR radio (92.3 FM) on Thursday, describing his wife's injuries as more severe than originally reported.

Metro said he and his wife, experienced hikers, were coming down the peak and were on flat terrain when the 74-year-old "stubbed her toe" and fell forward. She broke her nose, cut her face, and injured her left hand and right leg. Metro stemmed the bleeding and called rescuers, who sent the helicopter.

"I didn't know what to think," Metro said of seeing the rescue basket begin spinning wildly after it was aloft. "It was very scary and I think I went into shock."

Metro walked a mile back to his car, then drove to John C. Lincoln Hospital and was surprised to see that his wife appeared in worse shape than when he last saw her.

"I just couldn't believe her," he told the radio hosts. "Her eyes were all blackened. Her face was all black and blue. Her hands and feet were black and blue. I said 'Jesus, what happened?'"

A nurse explained to him that "the blood went all the way to her head and broke the small vessels in her face," he said.

His wife told him that "she thought she was going to die" while the basket spun. "She took deep breaths ... breathed in and out. She didn't know when it was all going to end."

Metro thanked the medical staff at the hospital. His wife is "still so weak she hasn't been able to get out of bed. We're hoping that changes. Her face is still swollen."



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Old 8th Jun 2019, 19:18
  #32 (permalink)  
 
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And while I'm thinking about it...

During the press conference they implied that the patient was none-the-worse from the operation. A bald face lie any way you look at it. At 74 she could well have died from this. I hope her recovery is complete. These folks should have stood up and taken responsibility for a very poorly executed job. They then should have explained clearly what causes this. What they did was weasel around by saying " sometimes this just happens" and that it caused no trauma to the patient. They did mention rotorwash as an issue and mumbled something about a broken tag line. Then on top of it, as the press conference ended, the Chief who introduced everyone started a round of hugs and smiles. Where were the adults during all this?
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Old 8th Jun 2019, 20:21
  #33 (permalink)  
 
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Originally Posted by roscoe1 View Post
During the press conference they implied that the patient was none-the-worse from the operation. A bald face lie any way you look at it. At 74 she could well have died from this. I hope her recovery is complete. These folks should have stood up and taken responsibility for a very poorly executed job. They then should have explained clearly what causes this. What they did was weasel around by saying " sometimes this just happens" and that it caused no trauma to the patient. They did mention rotorwash as an issue and mumbled something about a broken tag line. Then on top of it, as the press conference ended, the Chief who introduced everyone started a round of hugs and smiles. Where were the adults during all this?
^^^^This x 10

No operation is perfect all the time.
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Old 8th Jun 2019, 21:50
  #34 (permalink)  
 
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I seem to recall using a special "anti-spin" cable on the hoist that would prevent this problem.
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Old 9th Jun 2019, 03:55
  #35 (permalink)  
 
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Anti spin cable

Never heard of that. All the hooks have swivel bearings. I doubt very much that the cable was twisting during that E ticket ride. There are only one or maybe two wire rope manufacturers that make hoist cables and the construction is the same. They are a special construction that is not found in other applications that I know of but spin resistant isn't a listed characteristic.
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Old 9th Jun 2019, 14:09
  #36 (permalink)  
 
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Well the good news is that there has probably never been a better time to be rescued by the good looking Phoenix fire department.

Concerning the physiological effects of the incident , I suspect having the rotation point centered about the midriff and thus "centrifugal/hydraulic balanced" would mitigate lopsided blood pressure increase somewhat. I 'd hazard a guess that negative G tolerance is likely much higher in this configuration versus the oft quoted -2 to -3 of fighter pilots/astronauts.

Now can you come up with a better set of test subjects than the Phoenix fire dept. spokes team?
Perhaps a follow up press conference with the canned plastic air of a primetime TV denture advertisement.
Whirling down from 8 g's , then sitting up straight "See..just fine! Ready to start the day!"
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Old 10th Jun 2019, 12:35
  #37 (permalink)  
 
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Originally Posted by Three Lima Charlie View Post
I seem to recall using a special "anti-spin" cable on the hoist that would prevent this problem.
All hoisting cables are generally of the low twist design.
Meaning they resist the unwinding of the twisted strands when the cable is under load.
Rotarion resistant

This has nothing to do with the rotation of the basket. If a swivel would not have been fitted. You would see the hoist cable coil up.

SLB
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Old 10th Jun 2019, 19:43
  #38 (permalink)  
 
Join Date: Sep 2017
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i'm no designer by any means, but one would think with all the smarter people out there, a swivel could be designed to rotate, yet resist free rotation. All it has to do is slow the spin caused by rotor wash and spin before the cable balls up. those are two values that can be determined, and in my humble opinion, a value that can be adjusted for.
We have had roller wheels in our shoes, eyeglasses that automatically adjust to the light, and light switches that clap on and clap off for ages. Can we get a swivel that does more than freewheel uncontrollably??
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Old 10th Jun 2019, 20:52
  #39 (permalink)  
 
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The Baumann has a ring at the head through which the tag line must pass, before being secured to the upper carabiner. Failure to route via this ring renders positioning control all but impossible. I have watched the video a few times and it looks like the tag line bypasses this ring and is attached directly to the upper biner, allowing the Baumann to spin.

We don't employ a weak link. The tag line end is secured to the bag from which it is fed, and the bag weighted with a suitable rock so that the entire line can be flown, in the event of hoist failure, without fear of snagging the tail rotor.

Pilot positions back and left after lift, until he can see the tag line operator. This provides a good hover reference for the pilot, takes a workload off the hoist operator, and provides the tag line operator a good angle with which to control the stretcher. The patient's head is always forward. The distance one can move back and left is determined by the hover height, obstacle clearance and length of the tag line.

It is not possible to enter the stretcher directly to the cabin in the 109/119, one is required to seek safe landing area to repackage the patient to inside due further transportation.

One other observation - landing with the stretcher on the hook could shock load the hoist. We hoist out again from a low hover to ground handlers at the staging area.

Many basic errors here, but looks to me like the error chain started with the stretcher rigging.
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Old 10th Jun 2019, 21:55
  #40 (permalink)  
 
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Originally Posted by India Four Two View Post
I was bored and so I did a physics refresher. I timed the 10 fastest rotations to take about 8 seconds, so a period of 0.8 seconds. Assuming a 1.6 m patient, the maximum G force at her head would be about 0.6 .
How did you calculate that?
The circumference of the circle her head executed was 5m (1,6m *Pi).
The rotational speed was thus 5m/0,8s = 6,3m/s.
Lateral acceleration =v^2/r.
=49m/s^2 = 5g.
That is not only unpleasant. That is bordering on dangerous.


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