UK AAIB (H) Jan 2020
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How 'catestrophic' would it be if
EC135 MR actuator tie-bar fracture while lifting off, lands but heavy damage. Link
occurred in the cruise? Total loss of control?
Cant help thinking this would have been awkward if it had not been at only 4ft ?
EC135 MR actuator tie-bar fracture while lifting off, lands but heavy damage. Link
occurred in the cruise? Total loss of control?
Cant help thinking this would have been awkward if it had not been at only 4ft ?
How 'catestrophic' would it be if
EC135 MR actuator tie-bar fracture while lifting off, lands but heavy damage. Link
occurred in the cruise? Total loss of control?
Cant help thinking this would have been awkward if it had not been at only 4ft ?
EC135 MR actuator tie-bar fracture while lifting off, lands but heavy damage. Link
occurred in the cruise? Total loss of control?
Cant help thinking this would have been awkward if it had not been at only 4ft ?
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As we were just about to go offshore, the likelihood of knowing the cause would never of happened and there would be a hundreds of aircraft flying around with potentially the same defect. We'll take this for the TEAM..... Fly safe
Cheers
TeeS
How 'catestrophic' would it be if
EC135 MR actuator tie-bar fracture while lifting off, lands but heavy damage. Link
occurred in the cruise? Total loss of control?
Cant help thinking this would have been awkward if it had not been at only 4ft ?
EC135 MR actuator tie-bar fracture while lifting off, lands but heavy damage. Link
occurred in the cruise? Total loss of control?
Cant help thinking this would have been awkward if it had not been at only 4ft ?
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"the cyclic pitch actuator that let go" or maybe one of the three double actuators
1x10^-9 is a bogus fantasy as we see with the terrible toll this delusion results in
would have been a wild ride but that sort of thing has been survived before (swash plate from 2 grand)
1x10^-9 is a bogus fantasy as we see with the terrible toll this delusion results in
would have been a wild ride but that sort of thing has been survived before (swash plate from 2 grand)
"the cyclic pitch actuator that let go" or maybe one of the three double actuators
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212: "What would your solution be"
I would try and do what this pilot did and have it happen at 4ft.
Engines?!?!?! overrated !!! better to put the effort into important real things
I would try and do what this pilot did and have it happen at 4ft.
Engines?!?!?! overrated !!! better to put the effort into important real things
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We await your brand of simple yet effective servos to hit the helicopter market AnFI so we can marvel at your brilliance............
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Engines?!?!?! overrated !!! better to put the effort into important real things
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"We await your brand of simple yet effective servos to hit the helicopter market"
I think Bell, Robinson and others make a historically reliable single hydraulic servo arragement.
Certainly duplication of those would be unwarrented on a weight/reliability/cost/complication consideration.
(and MD helicopters achieve 100% reliabilty of servos by not having any)
One of the odd things about the regulation is that it pushes people into duplication of the servos without much consideration for the reliability of the common connection to them. for example imagine 10^-14 heavy, complex and expensive items held together by 10^-7 items (as in this case?)
I think Bell, Robinson and others make a historically reliable single hydraulic servo arragement.
Certainly duplication of those would be unwarrented on a weight/reliability/cost/complication consideration.
(and MD helicopters achieve 100% reliabilty of servos by not having any)
One of the odd things about the regulation is that it pushes people into duplication of the servos without much consideration for the reliability of the common connection to them. for example imagine 10^-14 heavy, complex and expensive items held together by 10^-7 items (as in this case?)
Last edited by AnFI; 4th Feb 2020 at 16:17. Reason: adding MD
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Single servos are acceptable on an aircraft where control feedback forces are low enough for the pilot to fly in full manual control. This is definitely not the case for larger helicopters. I wouldn't want to fly any aircraft knowing that if the single hydraulics system failed I would be another passenger - I've had too many hydraulic failures in the past; some of them the result of a simple crush washer leak or flexible hose failure.
Also, without servos there can be no SAS or autopilot. Having been required to operate totally unstabilised, untrimmable/"floppy stick" helicopters IFR/IMC in the past (and properly trained to do it) I have no pressing desire to have to do so ever again.
Also, without servos there can be no SAS or autopilot. Having been required to operate totally unstabilised, untrimmable/"floppy stick" helicopters IFR/IMC in the past (and properly trained to do it) I have no pressing desire to have to do so ever again.
And, whilst there will always be some single points of failure possible in any helicopter, where duplication is achievable without enormous weight penalty, it is desirable to provide redundancy and also required for IFR certification.
Much safer than having the single point of failure as the over-confident pilot who may make all sorts of errors of judgement and poor decisions leading to serviceable aircraft getting wet.
Much safer than having the single point of failure as the over-confident pilot who may make all sorts of errors of judgement and poor decisions leading to serviceable aircraft getting wet.
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Crab: "where duplication is achievable without enormous weight penalty, it is desirable to provide redundancy"
good point, quite right.
It is about measuring how worthwhile it is. Not ONLY in terms of weight, which is important.
A helicopter carrying only safety equipment is doing nothing useful. Duplication is a safety strategy that needs justification.
(carrying a defribulator is a safety strategy, in an A380 is probably justifiable, in a 139 probably not, kinda obvious really)
Multi Pilot: sure quite right too, much higher yeilding safety contribution.
Also saves aircraft from sheer incompetant/arrogant handling mishaps...
good point, quite right.
It is about measuring how worthwhile it is. Not ONLY in terms of weight, which is important.
A helicopter carrying only safety equipment is doing nothing useful. Duplication is a safety strategy that needs justification.
(carrying a defribulator is a safety strategy, in an A380 is probably justifiable, in a 139 probably not, kinda obvious really)
Multi Pilot: sure quite right too, much higher yeilding safety contribution.
Also saves aircraft from sheer incompetant/arrogant handling mishaps...
You should know that even in multi pilot ops a poor cockpit gradient or absence of CRM can still cause problems - you know the sort of thing where an ego-driven PIC makes a series of poor decisions that the hapless co-pilot or pilot under training doesn't feel he/she can challenge..............and suddenly they are bobbing in the oggin......
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