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Helicopter down outside Leicester City Football Club

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Helicopter down outside Leicester City Football Club

Old 2nd Nov 2018, 03:55
  #461 (permalink)  
 
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@gullibell... Thank you for jumping in...... I was establishing the principle rather than trying to teach the technique!

@Jagwar... Good point about the Canada Geese. They are substantial birds and would one damage a TR? Who knows? They are however big birds that would probably show up on the video clip and they do tend to fly around in pretty formations, generally only flying by day. If there are significant bird remains on the ground, they will be found by the AAIB.
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Old 2nd Nov 2018, 07:43
  #462 (permalink)  
 
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So I’m just reading the various actions to take to maximise the probability of the theoretical best possible outcome, and I can’t help wondering why not use some or all left cyclic in addition to the forward cyclic to get the desired helpful airflow against the vertical stabiliser?

Last edited by player104; 2nd Nov 2018 at 08:55.
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Old 2nd Nov 2018, 07:46
  #463 (permalink)  
 
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Originally Posted by Magplug
If you are in a hover high above the ground then your chances of a tidy touchdown diminish with height....The chances of a succcessful EOL from a free-air hover of between 50 and 1000 feet are negligible.... even before you consider the complication of the confined area beneath you..... that's the dead man's curve.
So, if some of the observations above are correct and the pilot chose to climb to an unusually high hover, why might he have done so?
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Old 2nd Nov 2018, 08:11
  #464 (permalink)  
 
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Originally Posted by Gustosomerset
So, if some of the observations above are correct and the pilot chose to climb to an unusually high hover, why might he have done so?
High does not imply unusual. 50ft, 100ft, 1000ft could all be described as high hovers. There could be any number of reasons why the pilot might extend the climb beyond a minimum required to safely commit to the take-off, or none. No implication can be drawn as to it being either unusual or unsafe in this context.
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Old 2nd Nov 2018, 08:44
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OK, thanks. I understand. I guess I was just trying to see if any implication could be drawn from what some observers seemed to describe as an 'unusual' take-off. Evidently not.
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Old 2nd Nov 2018, 09:29
  #466 (permalink)  
 
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Originally Posted by Magplug
The mention of 'dead man's curve' by the media is not so much rubbish as is being represented above.

<snip>

The chances of a successful EOL from a free-air hover of between 50 and 1000 feet are negligible.... even before you consider the complication of the confined area beneath you..... that's the dead man's curve.
When I did my PPL(H) in 1998, an AFI demoed an auto from the hover at 1,000'. Rolled off the throttle, dumped collective, pedal turned through 180, controlled RRPM with lever, nosed down for forward airspeed, flared and cushioned landing with lever in the normal way. Type was R-22.

I was only shown it because I asked to see it, but when I asked what its real-world applicability was, they said it would most likely be a skill for pilots doing line work and pylon work. They seemed to suggest that if you took out the pedal turn, you could achieve the same from significantly lower than that.
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Old 2nd Nov 2018, 09:32
  #467 (permalink)  
 
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Gusto, despite what some ‘experts’ are saying that take off was quite normal.
Remember Ex is a has been and spurts is a little more than a drip!
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Old 2nd Nov 2018, 09:44
  #468 (permalink)  
 
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I have some experience of crash investigations, helicopter engineering and statistics.

Let me shed some light in response to previous comments on the TR:
@ The pdf file below has a blown-up section of an image at the crash site (I can't yet post images directly). It clearly shows that:
@The TR was complete and attached at impact.
@ One blade was burnt by the fire after impact and appears to be broken in 2, with the outer portion lying on the boom just below the remaining portion..
@ One blade had damage to its tip.
@ IMO the lack of damage to the blades suggests the TR was turning very slowly or not at all on impact.
@ IMO the damage to the blade at the right bottom corner of the image almost certainly occured on impact with the ground.
@ IMO the damage to the burnt blade is consistent with the rotor not turning on impact and the blade fracturing, possibly helped to fall off by the post-crash fire.

On a final note, that a TR failure is a rare occurrence is essentially irrelevant to assessing whether it occured here or not. Even if it is a 100 million to one chance of occurring, it will occur to someone; we are not looking at the other 99,999,999 flights where it didn't occur.
Attached Files
File Type: pdf
GGSKP_TailRotor_CrashSite.pdf (171.0 KB, 492 views)
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Old 2nd Nov 2018, 09:46
  #469 (permalink)  
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Removal from scene begins

https://www.bbc.com/news/uk-england-...shire-46069679
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Old 2nd Nov 2018, 09:46
  #470 (permalink)  
 
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Originally Posted by Magplug
@gullibell... Thank you for jumping in...... I was establishing the principle rather than trying to teach the technique!

@Jagwar... Good point about the Canada Geese. They are substantial birds and would one damage a TR? Who knows? They are however big birds that would probably show up on the video clip and they do tend to fly around in pretty formations, generally only flying by day. If there are significant bird remains on the ground, they will be found by the AAIB.
Magplug: take a look at Google maps , the river forms a large basin only 50m from the stadium , I live near water and birds (ducks, geese) regularly land in the early evening even when dark , but not in formation I hasten to add !
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Old 2nd Nov 2018, 09:48
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Originally Posted by asdf1234
It's my understanding that the passenger pilot had a fixed wing licence and not a rotary wing licence .if that is the case, and please correct me if I'm wrong, how would her fixed wing experience help her in a rotary wing environment?
She would know what yaw is. Also know what the pedals do. And be an extra pair of eyes for the pilot.

Last edited by b1obthebuilder; 2nd Nov 2018 at 11:06.
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Old 2nd Nov 2018, 10:13
  #472 (permalink)  
 
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Originally Posted by G0ULI
I know that the weather at the time would appear to contradict the formation of a vortex ring, but could the explanation be as simple as that? High power vertical slightly reversed climb followed by a turn and drift into a vortex of descending air?
I naively believed vortex ring susceptibility was down to forward (or other direction) airspeed, rate of descent, and application of power. Remove any one of the three and the conditions cease to exist. I'll have to go back to basics to factor in weather.

For everyone's benefit, where can we find a comprehensive table of the weather factors, and precisely how they similarly cause - or 'contradict the formation of vortex ring', as you put it. I'm not convinced you know what vortex ring state is, given your phraseology.
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Old 2nd Nov 2018, 10:15
  #473 (permalink)  
 
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Don't panic!

Originally Posted by The Old Fat One
Guys and girls that fly helicopters, or are learning to fly helicopters, will be able to discern the valuable posts from the obvious "b*****ks" or at least ask questions if they require clarification.
It's pretty clear which posts are "b*****ks" even to those of us who are mere SLF. I can understand how it must be immensely frustrating to the pros to see the drivel, but I don't think they should worry too much about it. From the descriptions on here and looking at the videos, it's clear to even the layman that if the helicopter is going round in circles the most likely reason is because something bad has happened at the back end. As for the exact cause, well the AAIB have a good track record by all accounts, and they now have the data recorder contents as well as the wreckage, photos and videos:

https://www.gov.uk/government/news/u...ccident-g-vskp
The digital flight recorder is in our laboratory. Although subject to intense heat in the post-accident fire, initial work on it has allowed us to successfully download the recordings. Our inspectors are verifying the extracted information and have started the detailed analysis of its contents.We would like to thank everyone who responded to our witness appeal. Our investigators are examining the videos and photographs we have received.
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Old 2nd Nov 2018, 10:28
  #474 (permalink)  
 
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Originally Posted by Ewan Whosearmy
When I did my PPL(H) in 1998, an AFI demoed an auto from the hover at 1,000'. Rolled off the throttle, dumped collective, pedal turned through 180, controlled RRPM with lever, nosed down for forward airspeed, flared and cushioned landing with lever in the normal way. Type was R-22.

I was only shown it because I asked to see it, but when I asked what its real-world applicability was, they said it would most likely be a skill for pilots doing line work and pylon work. They seemed to suggest that if you took out the pedal turn, you could achieve the same from significantly lower than that.
But that was a simulated engine failure: The only yaw reaction is the one induced by the planned actions of the AFI. This accident looks like a catastrophic anti-torque failure in a helicopter with a much higher mass. The response will always be behind the event and the attitude of the aircraft at the point of failure and immediately following failure is not known. I really don‘t think a comparison can be made.

As an aside, the R22 will also indulge maneuvers that an AW169 almost certainly wouldn‘t. Zero speed auto? Expect an extremely dangerous rate of descent once the aircraft has finished accelerating (this in itself would require hundreds of feet) - lethal at low altitudes; 180 pedal turn during such an auto would also likely cause huge structural stress. Can’t imagine test pilots having that high on their list of things to try.

Last edited by Torquetalk; 2nd Nov 2018 at 10:42.
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Old 2nd Nov 2018, 10:31
  #475 (permalink)  
 
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From the CV & FDR the experts can recreate the flight using the pilot’s inputs and the aircraft’s controls actual positions.

They should reasonably quickly know if there was a failure of the TRDS, TRGB or TR controls.

If there was a mechanical failure they should be able to check the HUMS data to see if it could have been spotted before it failed. If it could, they can check other AW169 aircraft HUMS data for similar trend(s) (this is much quicker and cheaper than grounding all similar aircraft).

It is vitally important that all parties are open and honest in the interests of Flight Safety. I fear that some may be less inclined to be so. Time will tell.

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Old 2nd Nov 2018, 10:39
  #476 (permalink)  
 
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Originally Posted by b1obthebuilder
She would know what yaw is. Also know what the peddles do. And be an extra pair of eyes for the pilot.
Extra eyes: No question,
Flight controls: Considering the pilot's professional background, I would be surprised if the fixed wing pilot onboard didn't have the skill to fly that aircraft under normal circumstances.

My interest would be whether a pilot with an experience and skills profile similar to her would be able to take on an aircraft at that height (that has already entered an unusual attitude) and recover from that successfully.
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Old 2nd Nov 2018, 10:49
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Originally Posted by Sir Niall Dementia
Unlikely that incapacitation could cause a reaction like that.SND
What would an aircraft response congruent with pilot incapacitation look like?
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Old 2nd Nov 2018, 11:00
  #478 (permalink)  
 
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Originally Posted by Mitchaa
It certainly looks like a mechanical failure, 99% certainty based on the videos. Yet no emergency AD? No grounding? No response at all.
In order to justify a grounding there would have to be an indication of a general design flaw. In order to identify this they have to analyse what broke and how. I guess they are simply not at that point, yet.
For issuing an AD you need to have an idea what exactly to look for. Also this requires the identification what gave first and how. See above.
It could also simply be a maintenance issue (for the sake of the mechanics who last serviced it i surely do hope not) or indeed a Goose hitting the TR. Re the question if a Goose can damage a TR: You can bet so. Geese are veeery substantial animals (up to 15lbs !). When people are worried about a tiny DJI wiping out a TR, think about what an object 7 times as heavy will do.
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Old 2nd Nov 2018, 11:05
  #479 (permalink)  
 
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Originally Posted by flyems
What would an aircraft response congruent with pilot incapacitation look like?
How should anyone know?
That surely depends on what the last action/reaction before passing out was:
Could be stepping in one pedal.
Could be pulling/pushing/doing something else with the cyclic.
Could be pulling/pushing the collective.
Could be anything.
Could be nothing at all.
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Old 2nd Nov 2018, 11:27
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Originally Posted by Torquetalk

But that was a simulated engine failure: <snip>. I really don‘t think a comparison can be made.
Understood. I was simply responding to the catch-all comment that no helicopter can survive an engine failure (he wasn't talking about TR failure) "from a free air hover between 50' and 1,000'".
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