EC225 crash near Bergen, Norway April 2016
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Another PPRuNe Success!
So all the people who said the epicyclic module wasn't visible, just hadn't looked hard enough.
And people with a clear memory of the pin arrangement were wrong.
But hey that won't stop people second guessing and pontificating I guess.
And people with a clear memory of the pin arrangement were wrong.
But hey that won't stop people second guessing and pontificating I guess.
hence why the CAA classed them as 3 different types.
From a pilot licensing perspective they are all variants i.e. one entry on you licence covers all variants. Refer to the EASA OSD for more information.
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Mitchaa
Do you seriously think that losing one of the three attachments transferring the load between rotors and fuselage would not lead to instant destruction? Dis you really say Airbus need to prove Newton is right when you realise you are not?
And by the way have you been deleting posts? Why would that be?
Apate
The 330 and 332 were added to the EASA TCDS of the 225 2 years after the 225 was certified (as a new type). The 225 certification basis was JAR-29 as of 1999 albeit with a very small number of exemptions and deviations.
Do you seriously think that losing one of the three attachments transferring the load between rotors and fuselage would not lead to instant destruction? Dis you really say Airbus need to prove Newton is right when you realise you are not?
And by the way have you been deleting posts? Why would that be?
Apate
The 330 and 332 were added to the EASA TCDS of the 225 2 years after the 225 was certified (as a new type). The 225 certification basis was JAR-29 as of 1999 albeit with a very small number of exemptions and deviations.
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The 3 pin and the 3 fix point of suspension bar is definitely different on each version L1 L2 and 225 and this point is clear....
at 140knot if you loose one suspension bar you take a tragically unbalanced on main rotor and this come out instantaneously and it's true for every helicopter....
And stop the comparaison with 225 and L2 the MGB is not the same the material inside is not the same.....
And you cannot discuss about the 225 without talk of this brother the 725 same MGB engine Rotor is exactly the same in military versions and sent in Afghanistan with shield 450kg, 2 machine gun, 1000L extra tank, 2 gunner , 8 commando it was so heavy he cannot take off normally, only running due to the weight and the altitude 2400m , for pick up the guy on ground he land only on top of hill for take off with the slope, it's was every flight at 100% of this capacity and he have never crash....
At this condition it's a other thing that to do a taxi at 3000 feet..... We are far of the limit of the aircraft...
And in every manual of human factor the mistake machine is only the human....
The torque need to be checked on suspension bar every 750h but do at 500h or every time the engine one is remove and that happens commonly...
Now because for many people the C C1 L1 L2 225 is only the same aircraft the super puma, how many millions hours is flying and how many time this problem appear????
only two time at this day one is REDL but it's maintenance problem the gear box was "saised" because the alarm was inhibited and the oil not drain result corrosion and one gear crank, block the main gear box and the rotor head came out with the speed...
And this one....if the EASA ask for check this part is certainly because something is missing or not clear...and if Airbus decide to take the risk to authorize the 225 at fly again maybe he think the design it's not the problem on this crash....
at 140knot if you loose one suspension bar you take a tragically unbalanced on main rotor and this come out instantaneously and it's true for every helicopter....
And stop the comparaison with 225 and L2 the MGB is not the same the material inside is not the same.....
And you cannot discuss about the 225 without talk of this brother the 725 same MGB engine Rotor is exactly the same in military versions and sent in Afghanistan with shield 450kg, 2 machine gun, 1000L extra tank, 2 gunner , 8 commando it was so heavy he cannot take off normally, only running due to the weight and the altitude 2400m , for pick up the guy on ground he land only on top of hill for take off with the slope, it's was every flight at 100% of this capacity and he have never crash....
At this condition it's a other thing that to do a taxi at 3000 feet..... We are far of the limit of the aircraft...
And in every manual of human factor the mistake machine is only the human....
The torque need to be checked on suspension bar every 750h but do at 500h or every time the engine one is remove and that happens commonly...
Now because for many people the C C1 L1 L2 225 is only the same aircraft the super puma, how many millions hours is flying and how many time this problem appear????
only two time at this day one is REDL but it's maintenance problem the gear box was "saised" because the alarm was inhibited and the oil not drain result corrosion and one gear crank, block the main gear box and the rotor head came out with the speed...
And this one....if the EASA ask for check this part is certainly because something is missing or not clear...and if Airbus decide to take the risk to authorize the 225 at fly again maybe he think the design it's not the problem on this crash....
Losing one suspension bar is highly likely to be terminal. Very quickly for that matter. Depending on how the bar came loose very possibly without much if any warning.
Someone called the bolts "Jesus bolts". I guess that nails it.
@Never Fretter: given that each of three mounts (well, six, pins at each end) presents to the design team "catastrophic if it fails" (since the design team have to look at all loads and failure modes) I suspect that a substantial safety factor was given the pins' design/dimension.
If I understand the way they attach correctly, the pins would fail in shear if they fail at all. (If I misunderstand the attachment method, apologies).
Two previous points that seem not to have been later corrected are:
@henra: nice pun, albeit tragic.
If I understand the way they attach correctly, the pins would fail in shear if they fail at all. (If I misunderstand the attachment method, apologies).
Two previous points that seem not to have been later corrected are:
- One of the pins is in a hard-to-get-to, hard-to-see place once installation is complete. Question is: "What is the inspection interval for condition/corrosion, etc for that mounting pin." (Since you have to get around the engine, is it a time consuming inspection procedure?).
- Corrosion: I dont' know what the pins are made of, but I'll guess it's a hardened steel. How much history does this fleet have (I am asking about all of the ones using this particular mounting pin mentioned above, not just one company's) of having to replace a pin during service due to corrosion discovered during an inspection or otherwise uncovered?
@henra: nice pun, albeit tragic.
From a maintenance point of view the Puma family falls into four separate groups.
330, 332L/L1, 332L2 and EC225.
These are the division lines where it is considered that a sufficient difference exists as to require a separate type rating for maintenance purposes.
This is defined by EASA regulations specifically Part 66..
So from a maintenance perspective North Sea Tiger is correct.
330, 332L/L1, 332L2 and EC225.
These are the division lines where it is considered that a sufficient difference exists as to require a separate type rating for maintenance purposes.
This is defined by EASA regulations specifically Part 66..
So from a maintenance perspective North Sea Tiger is correct.
Last edited by ericferret; 4th May 2016 at 20:32.
The 330 and 332 were added to the EASA TCDS of the 225 2 years after the 225 was certified (as a new type). The 225 certification basis was JAR-29 as of 1999 albeit with a very small number of exemptions and deviations.
The 225 was never a new type. As an example it would not have been allowed to gain the exemptions and reversions to Jar 29 Amdt 1 if it were a new type.
Airbus made a conscious decision to not certify as a new type, driven primarily by cost (see above exemptions and reversions!).
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Is it the epicyclic that is in front of the MGB in this picture?
http://bt.mnocdn.no/incoming/article...d=030520161246
http://bt.mnocdn.no/incoming/article...d=030520161246
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No theories. And no fantasies like some.
All factually correct. If they don't suit your irrelevant theories that's not my problem.
Quote:
The 330 and 332 were added to the EASA TCDS of the 225 2 years after the 225 was certified (as a new type). The 225 certification basis was JAR-29 as of 1999 albeit with a very small number of exemptions and deviations.
End Quote
Sorry, you couldn't be more wrong if you tried!
The 330 and 332 were added to the EASA TCDS of the 225 2 years after the 225 was certified (as a new type). The 225 certification basis was JAR-29 as of 1999 albeit with a very small number of exemptions and deviations.
End Quote
Sorry, you couldn't be more wrong if you tried!
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There seems to be the assumption by some earlier posters that improved vibration monitoring techniques might have identified an impending failure and prevented this accident.
I submit that while vibration monitoring is a good technique for analysing rotating components, it is possible for static components such as a gearbox casing to fail without any vibrational warning.
Dye penetration tests and X-rays prove only that a component is servicable at the time the test was carried out. A slight misalignment or incorrectly torqued bolts during reassembly or maintenance work at a later date could cause stresses that initiate a crack that then propogates without any sign of problems until the component suddenly fails in overload.
This process of fatigue cracking was first identified during testing after crashes of early Comet aircraft. Repeated stress allows seemingly insignificant flaws to grow over a period of time until sudden failure. A common factor in all the Comet crashes was that they all occured without warning. A redesign fixed the problem, but public faith in the aircraft was lost.
Testing and monitoring programs are a lot more stringent now but it seems that two nearly identical rotor separations have happened, although the exact root cause in each case is still to be determined.
Better vibration analysis and HUMS systems are probably not going to be the answer if the parts that fail are not actually moving, just providing a support structure.
I submit that while vibration monitoring is a good technique for analysing rotating components, it is possible for static components such as a gearbox casing to fail without any vibrational warning.
Dye penetration tests and X-rays prove only that a component is servicable at the time the test was carried out. A slight misalignment or incorrectly torqued bolts during reassembly or maintenance work at a later date could cause stresses that initiate a crack that then propogates without any sign of problems until the component suddenly fails in overload.
This process of fatigue cracking was first identified during testing after crashes of early Comet aircraft. Repeated stress allows seemingly insignificant flaws to grow over a period of time until sudden failure. A common factor in all the Comet crashes was that they all occured without warning. A redesign fixed the problem, but public faith in the aircraft was lost.
Testing and monitoring programs are a lot more stringent now but it seems that two nearly identical rotor separations have happened, although the exact root cause in each case is still to be determined.
Better vibration analysis and HUMS systems are probably not going to be the answer if the parts that fail are not actually moving, just providing a support structure.
Simply give the experts some time to find out what caused this horrible crash. What is the benefit of re-assuring yourself that it was one particular cause while still lacking sufficient and important information ?
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No, not instantaneous failure, I don't believe it.
So with that in mind and knowing the load capabilities the other 2 bars must have, would a very slow decent on an a/c relatively lightly loaded have such a catastrophic failure with no warning even if and I do mean IF one bar failed?
Seems pretty hard to believe, for me who has zero experience/knowledge with either design or maintenance of a 225.
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If you ask me I an not imagine that the aircraft was designed to fly without a suspension bar, rather than say , without one main rotor blade . . .
Just the same would happen if you broke one suspension link doing 100km/h with your car, the rest of the links are not made to take up the increased load and your wheel is likely to break of and/or cause major control problems.
If the front bar came loose the gearbox would probably tilt backward and the airframe pitch down to the degree that the MRB would come in contact with the tail within a split second ?
Of course all of the above are pure speculations from my side.
Just the same would happen if you broke one suspension link doing 100km/h with your car, the rest of the links are not made to take up the increased load and your wheel is likely to break of and/or cause major control problems.
If the front bar came loose the gearbox would probably tilt backward and the airframe pitch down to the degree that the MRB would come in contact with the tail within a split second ?
Of course all of the above are pure speculations from my side.
Outwest, I think you are underestimating the forces generated by an out-of-balance mass rotating at considerable speed and in the process of losing control inputs.