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Helicopter down outside Leicester City Football Club

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Helicopter down outside Leicester City Football Club

Old 6th Nov 2018, 06:29
  #601 (permalink)  
 
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Originally Posted by bumpthump View Post
Non pilot question. I (think) I understand the need for the yaw to port so the pilot can keep line of sight with his departure point.
Once he yaws back to starboard and loses sight of his departure point, is this part of the TDP (ie, he is now committed to generating some airspeed), and at this point when he yaws round to his intended departure route, has he ceased climbing?

Hope you guys are ok with layman questions of this nature.
the yaw to keep the point in sight is in the 139 confined procedure
in the 169 variable tdp procedure you keep the point in sight between your pedals
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Old 6th Nov 2018, 06:33
  #602 (permalink)  
 
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Originally Posted by gulliBell View Post
TR control malfunctions never cause loss of control of the helicopter. Not to the extent we saw in the video.
These two sentences contradict each other.
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Old 6th Nov 2018, 06:37
  #603 (permalink)  
 
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Originally Posted by [email protected] View Post
Bumpthump - at TDP, if using the AW confined area profile, the yaw offset to provide sight of the LS is taken out as the nose is pushed forwards to gain speed. thereafter it is as Shytorque says
In the instance of the 169 variable TDP procedure itís not necessary because flown correctly you should have the pad (and reject area) in full view between the pedals through the chin window all the way up to TDP. You arenít needing a good visual picture of what is hidden by the instrument panel. Offsetting could actually lead to a condition where you have the wrong sight picture through the pedals. There is nothing in the video to suggest he did offset the nose left during the initial manoeuvre - itís looks perfectly straight.

AW169 QRH - The G&E H/H variable TDP consists of a slow (less than 300 fpm) climb above the take off surface maintaining the centre of the take off surface in sight between the yaw pedals up to TDP. The pilot then rotates to transition to forward flight and into the climb
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Old 6th Nov 2018, 08:23
  #604 (permalink)  
 
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Mandatory sb

In the mean time lhd has issued a mandatory alert sb on the whole 169 fleet. An ispection on TR flight control
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Old 6th Nov 2018, 10:15
  #605 (permalink)  
 
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Pointing towards a possible maintenance error?

E. DESCRIPTION
Following an in service event, this Service Bulletin requires an urgent check of the
proper installation and functionality of the Tail Rotor servo-actuator feedback lever
installation and interface on the back end of the component.
Incorrect installation may lead to loss of Tail Rotor control which, depending on the
flight condition, could lead to loss of control of the aircraft.
Feedback on the compliance to this Service Bulletin is required


3. Perform a visual inspection of the input lever of the TR servo-actuator:
3.1 With reference to Figure 1 and Figure 2 perform an in situ inspection of the nut
(60), the cotter pin (50), the lock-wire and the hinge bracket element (90)
connected to the lever feedback link (110) for condition and absence of damage.
3.2 Check the connection elements of the input lever (110) of the TR servo-actuator
taking particular care on the lever feedback link.


That's it, a simple 5 min visual inspection to make sure correct fitment of the nut/pin/lock wire.



Which maintenance organisation would have been looking after this helicopter?​​​​​​​
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Old 6th Nov 2018, 10:20
  #606 (permalink)  
 
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Which maintenance organisation would have been looking after this helicopter?
Sloane, I believe.
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Old 6th Nov 2018, 10:23
  #607 (permalink)  
 
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Originally Posted by silverelise View Post
These two sentences contradict each other.
No they don't. TR control malfunction you should still be able to land the helicopter at a place of your own choice, without any particular urgency, and without putting a scratch on the aircraft. TR drive malfunction is far more serious, with far less options available, which can very quickly lead to loss of control.
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Old 6th Nov 2018, 10:30
  #608 (permalink)  
 
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Originally Posted by gulliBell View Post
No they don't. TR control malfunction you should still be able to land the helicopter at a place of your own choice, without any particular urgency, and without putting a scratch on the aircraft. TR drive malfunction is far more serious, with far less options available, which can very quickly lead to loss of control.
I would tend to disagree. A TR Servo problem could include an uncommanded full input in either direction, which is the equivalent of applying full yaw pedal - which is very much like what we see in this incident. I fail to see how that can be considered 'controllable'. The S92 referred to earlier may have had a similar outcome if not a few feet above the deck.
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Old 6th Nov 2018, 10:30
  #609 (permalink)  
 
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This is now applicable to AW189 Fleet too.
I understand this would not normally be disturbed during maintenance.
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Old 6th Nov 2018, 10:33
  #610 (permalink)  
 
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Is it me or is that wire locking incorrect in the pic above? If you turn that to the left /anti-clockwise the wire locking unravels?

So the hinge bracket and nut hold the shaft onto the lever? If these loosen off then control input would be disabled? Struggling to see how you can fit that incorrectly?
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Old 6th Nov 2018, 10:34
  #611 (permalink)  
 
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Gullibell - sorry bud but you are missing an important point. TR Control Malfunction leading to a minimum power hard over is almost the same as Drive Failure and will force an EOL in most types of helicopters. Obviously most types with duplex hydraulics have design features to try to avoid hardovers, but if an input lever detaches...….blades throw off pitch...…..bye bye anti-torque thrust!
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Old 6th Nov 2018, 10:39
  #612 (permalink)  
 
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"s it me or is that wire locking incorrect in the pic above?"

I don't think so - looks as though the smaller bit on the end is part of the shaft and the big nut covered in blue is locked to it.
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Old 6th Nov 2018, 10:54
  #613 (permalink)  
 
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Originally Posted by oldbeefer View Post

I don't think so - looks as though the smaller bit on the end is part of the shaft and the big nut covered in blue is locked to it.
Yes, I see what you are saying now, I'm confusing myself with the nut and the bracket element. At first with the close up pic I thought it was a smaller nut on top of a larger hence my confusion but you are correct, it's locked to the end of the shaft by the looks of it.

Exploded diagram here...

60 is the nut
90 is the hinge bracket element
50 is the pin
110 is the lever feedback link




Trying to think of a way an installation maintenance error could be made here? The washer (140) on the wrong side of the bracket or incorrect wire locking so the nut isn't locked to the shaft?

Last edited by Mitchaa; 6th Nov 2018 at 11:28.
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Old 6th Nov 2018, 11:20
  #614 (permalink)  
 
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Is it certain that the "in service event" referred to in the SB is the Leicester accident?
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Old 6th Nov 2018, 11:27
  #615 (permalink)  
 
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Originally Posted by hoodie View Post
Is it certain that the "in service event" referred to in the SB is the Leicester accident?
It seems hard to imagine otherwise.

For info, in the S92 incident referred to above by simfly and me, from the report it says: " it yawed rapidly to the right, reaching a maximum rate of 30į per second. " Bear in mind it was 4 ft above the deck and landed after only 146į of yaw, imagine how it would have developed from the same position that Eric found himself in!!
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Old 6th Nov 2018, 11:31
  #616 (permalink)  
 
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Originally Posted by Sandy Toad View Post
This is now applicable to AW189 Fleet too.
I understand this would not normally be disturbed during maintenance.
Yes: 189-213
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Old 6th Nov 2018, 11:45
  #617 (permalink)  
 
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Inquest Opens BBC News

https://www.bbc.com/news/uk-england-...shire-46107923

Last edited by nomorehelosforme; 6th Nov 2018 at 12:08. Reason: spelling
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Old 6th Nov 2018, 12:05
  #618 (permalink)  
 
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From the AAIB site:


https://www.gov.uk/government/news/u...ccident-g-vskp
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Old 6th Nov 2018, 12:14
  #619 (permalink)  
 
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Originally Posted by [email protected] View Post
Bumpthump - at TDP, if using the AW confined area profile, the yaw offset to provide sight of the LS is taken out as the nose is pushed forwards to gain speed. thereafter it is as Shytorque says
Thank you.
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Old 6th Nov 2018, 12:25
  #620 (permalink)  
 
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Originally Posted by Mitchaa View Post
Trying to think of a way an installation maintenance error could be made here? The washer (140) on the wrong side of the bracket or incorrect wire locking so the nut isn't locked to the shaft?
My thoughts, and reading the wording of the inspection, makes me think that perhaps the safety wasn't there at all or failed, and the nut backed off completely. That of course would remove your pitch control completely

you would still have your T/R drive all the way thru this event, and that would explain the strike damage in the picture we debated earlier.
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