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Helicopter down outside Leicester City Football Club

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Helicopter down outside Leicester City Football Club

Old 15th Nov 2018, 20:54
  #781 (permalink)  
 
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Originally Posted by DOUBLE BOGEY View Post
Extract from report into AS355 TR Control Failure over Cardiff G-SAEW, Flown by an ex student of mine:
Errr....he was ex-Navy!
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Old 16th Nov 2018, 00:33
  #782 (permalink)  
 
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As a fixed wing pilot, can I ask; how do helicopter pilots inspect the tail rotor and its drive mechanism on the walk around? Are there inspection doors along the tail boom to enable inspection of every shaft joint? I donít recall seeing any in the helis we used to use for TV work. (Bolkow 105, Augusta 109, Twin Squirrel).

Given that the tail rotor seems to be so critical, why is there only one?. Would it not be safer if there were two separately driven tail rotors, or would that be overkill?
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Old 16th Nov 2018, 03:12
  #783 (permalink)  
 
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Originally Posted by DOUBLE BOGEY View Post
Extract from report into AS355 TR Control Failure over Cardiff G-SAEW, Flown by an ex student of mine:
DB... can you tell me the point of this illustration?
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Old 16th Nov 2018, 04:32
  #784 (permalink)  
 
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Originally Posted by Apate View Post
Errr....he was ex-Navy!

And your point being what exactly?
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Old 16th Nov 2018, 04:34
  #785 (permalink)  
 
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Originally Posted by Prawn2king4 View Post
Originally Posted by DOUBLE BOGEY View Post
Extract from report into AS355 TR Control Failure over Cardiff G-SAEW, Flown by an ex student of mine:

DB... can you tell me the point of this illustration?
Maybe that at least one of our Brethren has survived a similar situation. Its the technique he employed that is certainly of interest to me.
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Old 16th Nov 2018, 06:20
  #786 (permalink)  
 
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And it is the technique I would try to employ in the same situation.
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Old 16th Nov 2018, 07:05
  #787 (permalink)  

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Extract from report into AS355 TR Control Failure over Cardiff G-SAEW, Flown by an ex student of mine:
He used to post here as "Roofus".
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Old 16th Nov 2018, 07:51
  #788 (permalink)  
 
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Originally Posted by DOUBLE BOGEY View Post
And your point being what exactly?
How was he your "ex-student?"

We're not turning into Walter Mitty are we?
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Old 16th Nov 2018, 08:07
  #789 (permalink)  
 
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Originally Posted by Apate View Post
How was he your "ex-student?"

We're not turning into Walter Mitty are we?
Apate, As I recall I facilitated his AS355 Line Training. I could be wrong. Apologies if I used the word "Student" which I guess is reserved more for ab-initio.

I am certainly not claiming any Kudos from his outstanding act of airmanship. However, fwhy is this such an issue for you?
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Old 16th Nov 2018, 09:11
  #790 (permalink)  
 
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Devil

Originally Posted by DOUBLE BOGEY View Post
Apate, As I recall I facilitated his AS355 Line Training. I could be wrong. Apologies if I used the word "Student" which I guess is reserved more for ab-initio.

I am certainly not claiming any Kudos from his outstanding act of airmanship. However, fwhy is this such an issue for you?
Simples, you made a statement that I know not to be true.

You recollection regarding his AS355 Line Training is also incorrect!
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Old 16th Nov 2018, 09:20
  #791 (permalink)  
 
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Originally Posted by Apate View Post
Simples, you made a statement that I know not to be true.

You recollection regarding his AS355 Line Training is also incorrect!
I think you are mistaken. As I recall 2 pilots came from CHC/Brintel to Police Ops with Veritiair as somewhat of an experiment to convince good P2s to remain in the Company group by giving them something interesting to do.. I completed the Line Training for both in Cardiff. I am almost 100% sure he was one of the pilots. Unless of course I am having a fantasy moment!!! Always possible at my age. I sent you a PM.
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Old 16th Nov 2018, 10:09
  #792 (permalink)  
 
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Overdrive

SASless - no magic! I think the thread looked to be going in a "Left unattended/not properly pre-flighted" direction, due to some of the stated (but not confirmed) timings.
Not at all, it would have made no difference here as any issues were probably not visible. It just seemed a short time to me but I am comparing it with larger types.
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Old 16th Nov 2018, 13:28
  #793 (permalink)  
 
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Uplinker.

Things that need to be checked regularly are either on the outside (control linkages to the tail rotor, the blades themselves, as examples) or can be inspected either through a specific hatch or other access (for my 120, opening the rear cargo hatch allows me to stand inside the tail and check the battery and look down the inside of the tail boom, for example). Typically the tail rotor drive shaft itself does not require daily inspection and so it (and any bearings along its length) are not made easily accessible. They are, however, subject to specific inspection regimes defined by the manufacturer and performed by mechanics. Where regular inspection is needed (some Rotorway designs have a belt-drive) inspection is facilitated.

There will be many flight-critical parts of a flixed-wing that are similarly treated (looking for corrosion on wing spars is not facilitated by a myriad of little hatches that you can open in a walk-around).

I have not seen a "twin tail rotor" design, and I am not imaginative enough to speculate how that might work; sorry
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Old 16th Nov 2018, 14:55
  #794 (permalink)  
 
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Thanks for your reply. I think I would want to be able to inspect all the bearings and CV couplings along the drive shaft to the tail rotor.

Take your point about wing spars, but corrosion is a slow process, amply covered during C and D checks, and the wing spars do not have moving parts requiring lubrication because they do not rotate during flight! The couplings and bearings driving a tail rotor do, and can potentially break up quickly. I think I would want to check there was no visual evidence of bearing or joint stress, given how critical the tail rotor seems to be.

Twin tail rotors would simply be two shafts running down the tail boom, each driving a tail rotor, so there would be one rotor on each side of the tail boom instead of just one on one side.
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Old 16th Nov 2018, 15:13
  #795 (permalink)  
 
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Originally Posted by Uplinker View Post
As a fixed wing pilot, can I ask; how do helicopter pilots inspect the tail rotor and its drive mechanism on the walk around? Are there inspection doors along the tail boom to enable inspection of every shaft joint? I donít recall seeing any in the helis we used to use for TV work. (Bolkow 105, Augusta 109, Twin Squirrel).

Given that the tail rotor seems to be so critical, why is there only one?. Would it not be safer if there were two separately driven tail rotors, or would that be overkill?
Most likely dual tail rotors would result in an overall reduction in safety given that some tail rotor failures such as a departed blade can cause other damage. The complexity and added weight would also have a detrimental effect. One comparison are the chances of surviving a (single) engine failure at takeoff in single and dual engine light aircraft, I have heard they are roughly the same.

IF the cause of this accident was a servo loop failure/run to a stop it is not clear that a second tail rotor would have helped, especially given the extremely limited time to take action.

Question for those who know: Would an immediate shutdown of both engines have stopped the tail rotor or is the transmission coupling such that it would continue to spin as long as the main rotor was spinning?
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Old 16th Nov 2018, 15:17
  #796 (permalink)  
 
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Twin tail rotors would simply be two shafts running down the tail boom, each driving a tail rotor, so there would be one rotor on each side of the tail boom instead of just one on one side.
And contra rotating, it's not difficult to do, I designed and built one for a ROV. It worked great when one of the gearboxes failed...
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Old 16th Nov 2018, 15:37
  #797 (permalink)  
 
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Originally Posted by Uplinker View Post
Thanks for your reply. I think I would want to be able to inspect all the bearings and CV couplings along the drive shaft to the tail rotor.

Take your point about wing spars, but corrosion is a slow process, amply covered during C and D checks, and the wing spars do not have moving parts requiring lubrication because they do not rotate during flight! The couplings and bearings driving a tail rotor do, and can potentially break up quickly. I think I would want to check there was no visual evidence of bearing or joint stress, given how critical the tail rotor seems to be.

Twin tail rotors would simply be two shafts running down the tail boom, each driving a tail rotor, so there would be one rotor on each side of the tail boom instead of just one on one side.
Example of why it is important to inspect the tail rotor drive shaft : http://www.aaiu.ie/sites/default/fil...UGHLIN-0_0.PDF
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Old 16th Nov 2018, 17:12
  #798 (permalink)  

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Question for those who know: Would an immediate shutdown of both engines have stopped the tail rotor or is the transmission coupling such that it would continue to spin as long as the main rotor was spinning?




The tail rotor shaft is geared directly to the main rotor transmission, not to the engines.
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Old 16th Nov 2018, 22:54
  #799 (permalink)  
 
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Does the AW169 have a any HUMS or condition monitoring system?
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Old 17th Nov 2018, 08:31
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Yes it does
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