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Fatal Crash Broome 4th July 2020

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Fatal Crash Broome 4th July 2020

Old 13th Jul 2020, 22:37
  #41 (permalink)  
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Originally Posted by Fareastdriver View Post
How else are you going to do it?



The engineers did their best and passed it as fit to fly. The pilot accepted it on the basis that he trusted his engineers.

I feel sorry for the bloke that signed it off.
A lot of posters are talking about the helicopter being “signed out” or “ok’d” by the engineering staff.
No mention of this in the report.
Just saying...

A pilot who flew the helicopter on 2 July 2020 to Broome Airport reported feeling unusual vibrations through the tail rotor pedals. He described it as if something was repetitively tapping through the pedals. The pilot of the accident flight also conducted a short flight in the helicopter and confirmed the unusual vibrations.
  • Maintenance personnel conducted a dynamic tail rotor balance on 3 July 2020 (the day before the accident). The dynamic tail rotor balance was found to be within limits, and the maintenance personnel could not detect any unusual vibration on the ground.
  • The accident flight was the first flight since the maintenance was conducted. Overall, the helicopter had 291 recorded hours in service.
Also from the report:

The R44 Pilot’s Operating Handbook (POH) includes the following 'safety tip':

A change in the sound or vibration of the helicopter may indicate an impending failure of a critical component. If unusual sound or vibration begins in flight, make a safe landing and have the aircraft thoroughly inspected before flight is resumed. Hover helicopter close to the ground to verify problem is resolved, and then have aircraft reinspected before resuming free flight.

The ATSB strongly endorses this advice, and urges any R44 pilot that experiences unusual vibrations through the tail rotor pedals to land as soon as possible and follow the advice in the POH safety tip.
My BOLD in the quotes of report.

Last edited by Twist & Shout; 13th Jul 2020 at 23:25.
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Old 13th Jul 2020, 23:31
  #42 (permalink)  
 
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Originally Posted by gulliBell View Post
Not correct at all. The pilot reported a tapping in the pedals, not a vibration. Fundamental difference.
The report clearly says both, and both are extremely abnormal.
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Old 13th Jul 2020, 23:45
  #43 (permalink)  
 
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Originally Posted by Twist & Shout View Post
A lot of posters are talking about the helicopter being “signed out” or “ok’d” by the engineering staff.
No mention of this in the report.
Just saying...



Also from the report:
The difficulties in fault finding should not be underestimated, certain vibration and control faults can be difficult to isolate..

We had a 365 which was reported as having a slight kick in yaw on the ground and in the air. Much fault finding of the yaw system ensued with no answer.
Two of us after discussing it decided to take a new tack.
Kick on the ground, nosewheel castoring bearing had a hard spot.
Kick in the air, roll actuator problem.

My favourite
Aircraft shaking on the ground.
Main rotor balancing and structural inspections followed by undercarriage parts replaced. No improvement.
Watching the aircraft ground running from a slightly raised location the engineer with me said, " It looks as if it is in negative pitch"
We checked the rigging and the blades were about 2 degrees below allowable min pitch.
Airtested and pilot returned saying that was much better.
Vibration gone?
Yes and now you dont have to fly it with the collective under you arm pit.

Speechless.




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Old 14th Jul 2020, 00:58
  #44 (permalink)  
 
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Vibs

Unusual vibrations can be mysterious and hard to find sometimes..... had a hiller that had a high freq one time when it was on a trailer. Spent a couple of days changing tail rotor system components, and found the freq was caused by the thing being on the trailer.... live and learn.
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Old 14th Jul 2020, 05:00
  #45 (permalink)  
 
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Another issue you may encounter as someone who only flies one particular aircraft ( not type, but one particular aircraft, like a private owner tends to do ) is that you will just accept that a machine flies a certain way.
Very true, I have seen it many times.
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Old 14th Jul 2020, 09:23
  #46 (permalink)  
 
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But on the up-side, flying the same aircraft means that you do spot when something changes.

Some years back was once in an R44 with another pilot on climb-out when there was a solid loud metallic "thud" (like someone dropped a bag of tools in the rear footwell). Nothing more, no vibration or loss of power - all smooth. We looked at each other, and agreed immediate return. Engineering inspection followed but couldn't find a fault, told to hover it "heavy" to see if it would repeat. 15 min and no repeat, aircraft released to service but not with me in it. A couple of days later another pilot with commercial passengers onboard experienced the same "thud" in level flight. Made a PAN call and landed, aircraft recovered by road followed by head-scratching in engineering. Someone suggested looking at the Sprag Clutch, which requires disassembly and most shops cannot do. When disassembled it was destroyed internally - fault found.

Taught me one thing, if something strange happens and they can't find the fault, then the fault is still there.
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Old 14th Jul 2020, 12:22
  #47 (permalink)  
 
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Originally Posted by industry insider View Post
In this case the reported tick vibration wouldnít indicate an out of balance tail rotor to me. Out of balance is normally much more of a buzz through the pedals.

A simple dynamic balance for the reported problem doesnít seem like the correct maintenance action.

In addition to directly addressing the discrepancy, "Conditional Inspections", in AMM Chapter 5, should be consulted during non routine maintenance. This data includes
  • hypothetical and known causes of specific symptoms experienced by the flight crew or observed by others
  • potential hidden effects of flight envelope exceedances or other unusual events that occurred in flight or on the ground
  • actual root causes specific to the aircraft type in question, which is added to the manual as service experience is accrued
DS
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Old 15th Jul 2020, 03:19
  #48 (permalink)  
 
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John R81 wrote

But on the up-side, flying the same aircraft means that you do spot when something changes.
Not always if the change is gradual. Before the days of HUMS, I visited a base where one crew flew the same aircraft everyday. They were both very professional and were fussy about the state of the aircraft. I performed a line check on one of the crew and thought that the aircraft was a bit rough compared with the last time I had flown it a month prior. A track and balance showed it was close to the limit and had deteriorated, but the crew which flew it every day hadn't noticed.
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Old 15th Jul 2020, 22:31
  #49 (permalink)  
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Minor vibration changes can be difficult to pick up for many pilots, including me.
If the change is slow, and over a long period, even more so.

It’s “thread drift” here though. Vibes/tapping were reported by one pilot, confirmed by another. An out of balance TR was then eliminated as a source.
The RFM call’s for a low hover, followed by a shut down and re-inspection. (Assuming the Vibe was no longer present in the low hover)
Rather than the above procedure, the report seems to indicate, that pax were loaded for what was essentially a maintenance test flight.
Am I missing something?
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Old 16th Jul 2020, 06:02
  #50 (permalink)  
 
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Twist and Shout - I read it the same way as you.
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Old 17th Jul 2020, 09:41
  #51 (permalink)  
 
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Originally Posted by industry insider View Post
John R81 wrote



Not always if the change is gradual. Before the days of HUMS, I visited a base where one crew flew the same aircraft everyday. They were both very professional and were fussy about the state of the aircraft. I performed a line check on one of the crew and thought that the aircraft was a bit rough compared with the last time I had flown it a month prior. A track and balance showed it was close to the limit and had deteriorated, but the crew which flew it every day hadn't noticed.
This is a common phenomenon with human performance - ďThe boiling frog is a fable describing a frog being slowly boiled alive. The premise is that if a frog is put suddenly into boiling water, it will jump out, but if the frog is put in tepid water which is then brought to a boil slowly, it will not perceive the danger and will be cooked to death.ď

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Old 17th Jul 2020, 17:56
  #52 (permalink)  
 
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That's what happens with prawns when you buy them on the hoof.
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Old 2nd Sep 2020, 11:51
  #53 (permalink)  
 
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Preliminary report is out. Not conclusive yet.

https://www.atsb.gov.au/publications...r/ao-2020-033/
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Old 3rd Sep 2020, 08:26
  #54 (permalink)  
 
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Very concerning though that an aircraft could suffer what seems to be a catastrophic failure immediately after being inspected, and essentially given a clean bill of health - notwithstanding the engineer requiring a test flight - and that the maintenance pilot thought the site unsuitable for a check flight, leaving it for someone else to do even though the site was unsuitable.
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Old 3rd Sep 2020, 08:58
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And look at the total hours on the airframe. Glad I don't get into Robbo's
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Old 3rd Sep 2020, 10:12
  #56 (permalink)  
 
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Unhappy

Originally Posted by catseye View Post
And look at the total hours on the airframe. Glad I don't get into Robbo's
Welcome to the sad world of Robinson’s .....just part of the course; bits flinging off & failing on a frighteningly regular basis


Last edited by Senior Pilot; 3rd Sep 2020 at 10:50. Reason: Spelling
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Old 3rd Sep 2020, 10:40
  #57 (permalink)  
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Originally Posted by [email protected] View Post
Very concerning though that an aircraft could suffer what seems to be a catastrophic failure immediately after being inspected, and essentially given a clean bill of health - notwithstanding the engineer requiring a test flight - and that the maintenance pilot thought the site unsuitable for a check flight, leaving it for someone else to do even though the site was unsuitable.
With unsuspecting passengers.
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Old 3rd Sep 2020, 11:58
  #58 (permalink)  
 
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Originally Posted by Vertical Freedom View Post
Welcome to the sad world of Robinson’s .....just part of the course; bits flinging off & failing on a frighteningly regular basis

Yes, everyone knows I would be quick to respond to this, so without further ado...

VF, your statement is utter rubbish. If we assume that this event was caused by a catastrophic failure of some component (a fair assumption IMHO, although we may all yet find out differently in the end), such events are exceedingly rare in any make/model of helicopter, including Robinsons, and yet by no means unique to any one make/model helicopter, including Robinsons. It is trivially easy to demonstrate this. A 30 second Google search brings up this gem: https://tsb-bst.gc.ca/eng/rapports-r.../a11o0205.html An in-flight main rotor blade separation on a 206. Can you believe it, the venerable 206? Yes, we better stop flying all those, too! And with reference to another, similar incident on a 206 in the same article. Coming at it from the other direction, a search of the NTSB accident database will clearly demonstrate that bits do not fall of Robinson helicopters with any more or less frequency than any other type of helicopter. We've done that study to death on PPRuNe and yet you refuse to accept it because you lost someone close to you in a Robinson accident that you can't explain so you will forever blame the design and the company even though the statistics don't support your position.

Meanwhile, while remaining intellectually interested in the root cause of this accident, I don't worry so much because once is happenstance, twice is coincidence, but three times is enemy action, and we have never seen, and are not yet seeing, an epidemic of R44s shedding their tails in dramatic fashion. And if we did see it it would probably happen in one of those countries where they regularly and inappropriately thrash the bejeezus out of their R44s first, thus giving the US aviation community a chance to head off any incipient problems. Of course this is all very idle speculation in the best PPRuNe style.


Last edited by aa777888; 4th Sep 2020 at 02:55.
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Old 3rd Sep 2020, 12:33
  #59 (permalink)  
 
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[QUOTE=aa777888;10877530]Yes, everyone knows I would be quick to respond to this, so without further ado...


Here we go again.....
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Old 3rd Sep 2020, 17:13
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Originally Posted by Vertical Freedom View Post
Welcome to the sad world of Robinsonís .....just part of the course; bits flinging off & failing on a frighteningly regular basis

Itís not that robbies cleanse the gene pool, they unfortunately encourage punters who donít know better to join them.strangely enough the Robbie cult are always surprised when it happens.
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