End of the 225?
Never mind the chaff....there is some Wheat amongst the posts!
I am learning far more about Gearbox design and manufacturing, heat treatment, gear coatings, and bearing wear than I ever have....which does make for an interesting read of some of the posts.
This is a very serious situation, not only for AH and the Operators, but the Industry as a whole to include the Authority's that Certify Aircraft.
To lose two aircraft and all of the people in them as has happened....requires the causes be definitively identified no matter how much it costs or however long it takes.
It will require the dropping of Shields by every involved party if that is to happen.
There lies the major problem in my view....as there are too many vested interests that might not be as candid in their review as might be required.
We had a similar situation back when the 92 was having its problems but at least part of that was due to it being a brand new Machine having its teething problems. Those issues seem to have been identified and resolved.
Hopefully, the Gearbox issues with the 225 will be resolved as well and the Aircraft can be returned to service.
I am learning far more about Gearbox design and manufacturing, heat treatment, gear coatings, and bearing wear than I ever have....which does make for an interesting read of some of the posts.
This is a very serious situation, not only for AH and the Operators, but the Industry as a whole to include the Authority's that Certify Aircraft.
To lose two aircraft and all of the people in them as has happened....requires the causes be definitively identified no matter how much it costs or however long it takes.
It will require the dropping of Shields by every involved party if that is to happen.
There lies the major problem in my view....as there are too many vested interests that might not be as candid in their review as might be required.
We had a similar situation back when the 92 was having its problems but at least part of that was due to it being a brand new Machine having its teething problems. Those issues seem to have been identified and resolved.
Hopefully, the Gearbox issues with the 225 will be resolved as well and the Aircraft can be returned to service.
So now we have confirmation that there was a fire onboard the egyptair A320 without a cause for it (yet)... How come, the fixed wing world acts so differently than ours? Why haven't all A330s been grounded till the cause has been found?
Is the rotary word "over-reacting" or is the fixed wing world not doing enough because of much more money involved?
Is the rotary word "over-reacting" or is the fixed wing world not doing enough because of much more money involved?
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The client in the stuck wing world is us, if we don't want to fly on a type the airline laughs knowing there are plenty of other passengers. In rotary world the client is the oil company and if they say no there are no more passengers. It's the power they have as each company pays for many passengers.
Si
Si
So now we have confirmation that there was a fire onboard the egyptair A320 without a cause for it (yet)... How come, the fixed wing world acts so differently than ours? Why haven't all A330s been grounded till the cause has been found?
Is the rotary word "over-reacting" or is the fixed wing world not doing enough because of much more money involved?
Is the rotary word "over-reacting" or is the fixed wing world not doing enough because of much more money involved?
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Scanning thru posts that you don't find helpful just comes with using an open public forum. Much preferable to censorship.
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riff raff: "Unfortunately, the subject of rotorcraft gearbox design is very complex and not easy to summarize in a couple sentences of the typical post."
and that is why the risk assosciated with these gearboxes should be taken into account when the 2 engine solution is considered
it is not correct to say 1x10^-5 squared (1x10^-10) is the risk and it is a completely untrue premise
and that is why the risk assosciated with these gearboxes should be taken into account when the 2 engine solution is considered
it is not correct to say 1x10^-5 squared (1x10^-10) is the risk and it is a completely untrue premise
Can we just answer the original thread - the 225 is now a dead duck.
EC/AH flummoxed the industry lay time - even stating that fault could have been caused by a bead of sweat dropping into the shaft from a guy in Marseiile. FFS - they have an ology in BS - or as AH call it - Merde du Vache.
AH tried to get away with minimal last time - they have stretched max fro MGB and been found wanting.
EC/AH flummoxed the industry lay time - even stating that fault could have been caused by a bead of sweat dropping into the shaft from a guy in Marseiile. FFS - they have an ology in BS - or as AH call it - Merde du Vache.
AH tried to get away with minimal last time - they have stretched max fro MGB and been found wanting.
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This thread should read is the twin dead
its got nothing to do with being a 225
its got everything to do with what Ive been banging on about
its just a hideously complicated gearbox with hundreds of bearings and back up lubrication systems and all sorts of pig ignorant engineering solutions more fatally dangerous freewheel units than one needs to be exposed to this sort of problem is inherent in the Multi Engined approach
S92s 225s Merlins ec135 a109s all have multi engine related accidents often
a guy dies in London under a twin and a bunch of people die in a pub under a twin so theyre going to ban singles great logic guys ordinary people are sick of being kicked around by pompous ignorant elites
now its going to be twin only in the military too !!
totally nuts
its got nothing to do with being a 225
its got everything to do with what Ive been banging on about
its just a hideously complicated gearbox with hundreds of bearings and back up lubrication systems and all sorts of pig ignorant engineering solutions more fatally dangerous freewheel units than one needs to be exposed to this sort of problem is inherent in the Multi Engined approach
S92s 225s Merlins ec135 a109s all have multi engine related accidents often
a guy dies in London under a twin and a bunch of people die in a pub under a twin so theyre going to ban singles great logic guys ordinary people are sick of being kicked around by pompous ignorant elites
now its going to be twin only in the military too !!
totally nuts
Nope
Actually, it does.
Merlin isn't a twin, nor is the CH-53E. 
The S92 crash in Canada (Cougar) was not due to the input gears failing from the two engines, but output from the bevel to the TTO -- whether you had one or two engines driving the gear box has nothing to do with the box running out of oil and then failure of drive to the tail rotor.
Can you offer an example of an S92 accident that actually has to do with two engines?
AnFI, if all you have is a hammer, does everything really look like a nail?
The 225 has a particular design issue that will or won't be addressed successfully enough to return that fleet to service. Can't be a rush job, that would probably defeat the purpose.
its got nothing to do with being a 225
S92s 225s Merlins ec135 a109s all have multi engine related accidents often
The S92 crash in Canada (Cougar) was not due to the input gears failing from the two engines, but output from the bevel to the TTO -- whether you had one or two engines driving the gear box has nothing to do with the box running out of oil and then failure of drive to the tail rotor.
Can you offer an example of an S92 accident that actually has to do with two engines?
AnFI, if all you have is a hammer, does everything really look like a nail?
The 225 has a particular design issue that will or won't be addressed successfully enough to return that fleet to service. Can't be a rush job, that would probably defeat the purpose.
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Lone 50 4 ref
Anfi quote "its just a hideously complicated gearbox with hundreds of bearings and backup ....... to be exposed to this sort of problem is inherent in the Multi Engined approach "
ref hammer and nail metaphore its the illogical focus on engine related accidents as opposed to general system failures that deserves that parallel
engines are only a small proportion of accidents why is that hammer used when nails are so rare?
PCD "on and on and on and on....."
and eventually the point might get some serious consideration
helicopters are fundamentally simplex, the most reliable components are simplex, duplication and complexity are the helicopters enemy
Anfi quote "its just a hideously complicated gearbox with hundreds of bearings and backup ....... to be exposed to this sort of problem is inherent in the Multi Engined approach "
ref hammer and nail metaphore its the illogical focus on engine related accidents as opposed to general system failures that deserves that parallel
engines are only a small proportion of accidents why is that hammer used when nails are so rare?
PCD "on and on and on and on....."
and eventually the point might get some serious consideration
helicopters are fundamentally simplex, the most reliable components are simplex, duplication and complexity are the helicopters enemy
Last edited by AnFI; 17th Jul 2016 at 07:24.
They do have accidents but they are rare and they have to do with very demanding Usage profiles rather than the question 1 engine or two or even more. In this particular case the second stage epicyclic that apparently failed could give a flying f*ck if the first stage gear was driven by one, two or three donks.
The thought you are a helicopter pilot thoroughly scares me, seeing that you have obvious difficulties understanding the most basic causal inferences.
Banging on.....an empty Drum!
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The question regarding the future of twin engine helos is actually interesting.
First, consider the fundamental reason for using twin engines. It is primarily because existing turboshaft engine designs were not perceived as having an acceptable level of reliability for the given applications. On the other hand, using a single larger turboshaft engine would give better fuel efficiency and much lower manufacturing cost.
The new generation of turboshaft engines are far more reliable than previous ones. So I think we'll see more new helo designs using a single engine instead of twin engines.
First, consider the fundamental reason for using twin engines. It is primarily because existing turboshaft engine designs were not perceived as having an acceptable level of reliability for the given applications. On the other hand, using a single larger turboshaft engine would give better fuel efficiency and much lower manufacturing cost.
The new generation of turboshaft engines are far more reliable than previous ones. So I think we'll see more new helo designs using a single engine instead of twin engines.
First, consider the fundamental reason for using twin engines. It is primarily because existing turboshaft engine designs were not perceived as having an acceptable level of reliability for the given applications.
? So, nothing to do with getting you to LSALT, to a safe landing place or back on the deck or ground then....?edit:- Should've said in the event of an engine failure
Last edited by Evil Twin; 18th Jul 2016 at 21:15.
Quote:
First, consider the fundamental reason for using twin engines. It is primarily because existing turboshaft engine designs were not perceived as having an acceptable level of reliability for the given applications.
Hmmmmm....? So, nothing to do with getting you to LSALT, to a safe landing place or back on the deck or ground then....?
First, consider the fundamental reason for using twin engines. It is primarily because existing turboshaft engine designs were not perceived as having an acceptable level of reliability for the given applications.
Hmmmmm....? So, nothing to do with getting you to LSALT, to a safe landing place or back on the deck or ground then....?
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The question regarding the future of twin engine helos is actually interesting.
First, consider the fundamental reason for using twin engines. It is primarily because existing turboshaft engine designs were not perceived as having an acceptable level of reliability for the given applications. On the other hand, using a single larger turboshaft engine would give better fuel efficiency and much lower manufacturing cost.
The new generation of turboshaft engines are far more reliable than previous ones. So I think we'll see more new helo designs using a single engine instead of twin engines.
First, consider the fundamental reason for using twin engines. It is primarily because existing turboshaft engine designs were not perceived as having an acceptable level of reliability for the given applications. On the other hand, using a single larger turboshaft engine would give better fuel efficiency and much lower manufacturing cost.
The new generation of turboshaft engines are far more reliable than previous ones. So I think we'll see more new helo designs using a single engine instead of twin engines.
I only wish you were right, but me think we can only dream of it!
Davy
Last edited by singesavant; 18th Jul 2016 at 16:21.