Canadian Sea King replacement update
Rotor Pilot
'What one want over the sea is a helicopter that will not go to the fishes if one engine fails'
Yes the EH101 has successfully put itself with the fishes, following a modification by the manufacturers, when the rotor brake went on in flight. And, but for the grace of God, The Merlin would have totalled an airframe and crew when the RN aircraft at Culdrose shed its TR blade if it had not happened in a low hover over a flat surface.
Is the Merlin/101 safe following a single engine failure throughout its whole flight envelope? - I doubt it but how many single engine failures have brought catastrophe to twin engine helicopters in the hover? Not very many compared to the number of hours spent in the hover.
Westlands have made a great deal of this extra survivability in their marketing but their premise is flawed - if the twin engine aircraft has strong reliable engines (as most are nowadays) then the number of failures are greatly reduced. Why then sacrifice payload and range (massive fuel consumption with 3 engines running) to cater for an event that is outweighed statistically by TR malfunctions - why not spend the money on a decent TR hub in the first place.
'What one want over the sea is a helicopter that will not go to the fishes if one engine fails'
Yes the EH101 has successfully put itself with the fishes, following a modification by the manufacturers, when the rotor brake went on in flight. And, but for the grace of God, The Merlin would have totalled an airframe and crew when the RN aircraft at Culdrose shed its TR blade if it had not happened in a low hover over a flat surface.
Is the Merlin/101 safe following a single engine failure throughout its whole flight envelope? - I doubt it but how many single engine failures have brought catastrophe to twin engine helicopters in the hover? Not very many compared to the number of hours spent in the hover.
Westlands have made a great deal of this extra survivability in their marketing but their premise is flawed - if the twin engine aircraft has strong reliable engines (as most are nowadays) then the number of failures are greatly reduced. Why then sacrifice payload and range (massive fuel consumption with 3 engines running) to cater for an event that is outweighed statistically by TR malfunctions - why not spend the money on a decent TR hub in the first place.
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to continue [email protected]'s comment:
The third engine on the EH=101 is certainly needed, and without all three running, it falls pretty fast. I got a few emails from folks in the last few days with info.
The dead man's curve (where an engine failure will create a crash) is quite large on the EH-101, making those comments about an "extra engine" just not true. In spite of the protests of rotorpilot, the top of the dead man's curve for the EH is said to be over 400 feet on a hot day, and the bottom is supposed to be around 25 feet. That means from the hover at anywhere in between, you must land hard when one engine stops. Is that right, RotorPilot?
If the aircraft is anywhere near MGW, it will come down. and at MGW it has a Catagory A landback distance that is large. I have heard that it needs 1,000 ft runway at MGW, and that to do a small heliport vertical procedure, it must drop 5,000 lbs of GW.
As other folks have asked, where are your numbers, rotorpilot? Are you a rotor pilot?
The third engine on the EH=101 is certainly needed, and without all three running, it falls pretty fast. I got a few emails from folks in the last few days with info.
The dead man's curve (where an engine failure will create a crash) is quite large on the EH-101, making those comments about an "extra engine" just not true. In spite of the protests of rotorpilot, the top of the dead man's curve for the EH is said to be over 400 feet on a hot day, and the bottom is supposed to be around 25 feet. That means from the hover at anywhere in between, you must land hard when one engine stops. Is that right, RotorPilot?
If the aircraft is anywhere near MGW, it will come down. and at MGW it has a Catagory A landback distance that is large. I have heard that it needs 1,000 ft runway at MGW, and that to do a small heliport vertical procedure, it must drop 5,000 lbs of GW.
As other folks have asked, where are your numbers, rotorpilot? Are you a rotor pilot?
rjsqirrel,
This is an interesting debate but one for which there is generation of more heat than light.
I have no wish to get involved in these sematics but would like to point out that it is extremely unlikely that in a (representative) HV Diagram, the EH 101 would have an upper boundary of 400ft - if only because an engine failure will represent a loss of one third of the installed power.
In a contest of drop-down following an engine failure in the hover (or on take-off from a ship), it stands to reason that the EH101 is bound to win hands down.
This is an interesting debate but one for which there is generation of more heat than light.
I have no wish to get involved in these sematics but would like to point out that it is extremely unlikely that in a (representative) HV Diagram, the EH 101 would have an upper boundary of 400ft - if only because an engine failure will represent a loss of one third of the installed power.
In a contest of drop-down following an engine failure in the hover (or on take-off from a ship), it stands to reason that the EH101 is bound to win hands down.
JimL - that might be true if the remaining 2 engines could put all their remaining power through the MRGB to drive the rotors and it is my belief that the Merlin cannot do this. One of the good things that Westlands designed was the conformal, 3 pinion gearbox on the Lynx which allowed all the power from the remaining engine to drive the rotor following a power failure. Who built the gearbox for the 101? not Westlands - it was Augusta using conventional design. No doubt a variation on the 3 pinion MRGB would be offered as a mid-life update for the Merlin.
However, I agree that 400 feet is a little excessive - all that is required is enough nose down to achieve about 30 kts and it should fly away on 2 engines. But if your twin engine performance is that good, why do you need a third engine?
However, I agree that 400 feet is a little excessive - all that is required is enough nose down to achieve about 30 kts and it should fly away on 2 engines. But if your twin engine performance is that good, why do you need a third engine?
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I love all this pickering with regards to "my helicopter is better than yours".
I think it's very easy to pick faults with the EH-101 as it is in use and we are aware of it's real limitations compared to the H-92 which is not in an operational role just yet.
I think we need to wait until there's about 30-40 H92 out there doing various roles before we have some real data and then we can have a real fight!
And then somebody will have the right to say "told you so that my heli is better than yours".
I
I think it's very easy to pick faults with the EH-101 as it is in use and we are aware of it's real limitations compared to the H-92 which is not in an operational role just yet.
I think we need to wait until there's about 30-40 H92 out there doing various roles before we have some real data and then we can have a real fight!
And then somebody will have the right to say "told you so that my heli is better than yours".
I
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If you want a good competition to see which ship is the best, put a hook on them, and send them logging for six months...
The one with the best availability rate wins....
The one with the best availability rate wins....
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rjsquirel
You simply do not know what you are talking about.
To discuss anything one must imply that the other contender (so to speak) knows something about it. Not you case. Being so I refrain myself to answer to your diatribes.
[email protected]
In this thread, for the third time in less then a year, you contradicted my statements with false data and information. In this thread or in the other about the same subject, you had to declare yourself “standing corrected” about some basic specifics as the EH101 being, from its very beginning, a military machine developed to fulfill the requirements of several countries wishing to replace the Sea King.
Your “credit rating” with me is below zero, as I do not have the time or patience to “correct” basics that should be known by those engaged in given opinions, even as biased as yours. In fact I am not interested in correcting anything at all. My interest is just to discuss well-based and well fundamented opinions about something, even if drastically different points of view might emerge from those discussions. I never turn down a good fight of ideas.
So I am not going to “correct” any of your statements or "beliefs" but rather give some more data about the EH101. You will know where they fit.
cyclic_fondler
Exactly cyclic. Drawings don't fly so they don't crash either. That's why they have an imaculate safety record. 
On top of that they can be anything provided one can convince the buyer that the manufacturer will be able to make good on his promises. Kind of the Boeing Dreamliner that can be anything until it starts flying...
How come somebody buys 5 billion worth of promises is mind-boggling
The EH 101 is being flown everywhere, was deployed in the Balcans conflict, it is deployed in Iraq in extremely demanding conditions and will be packing soon elsewhere also very hot, very dry and very messy...
The H92 is "deployed" in Sikorsky's drawing board...
Oh BTW I almost forgot one thing:
Follow-up of the NH90 seems to be the HTH - Heavy Transport Helicopter for 70 troops intended to replace the twin engine CH53's in Europe and trying to give a run to Sikorsky's HLH (Heavy Lift Helicopter)... Number of engines they are thinking about ? THREE also !
Can you imagine the amount of payload they are going to loose to those engines ?
Well but this one is still in the "Dreamliner" phase. Not yet for sale.
The third engine on the EH=101 is certainly needed, and without all three running, it falls pretty fast. I got a few emails from folks in the last few days with info.
To discuss anything one must imply that the other contender (so to speak) knows something about it. Not you case. Being so I refrain myself to answer to your diatribes.
[email protected]
In this thread, for the third time in less then a year, you contradicted my statements with false data and information. In this thread or in the other about the same subject, you had to declare yourself “standing corrected” about some basic specifics as the EH101 being, from its very beginning, a military machine developed to fulfill the requirements of several countries wishing to replace the Sea King.
Your “credit rating” with me is below zero, as I do not have the time or patience to “correct” basics that should be known by those engaged in given opinions, even as biased as yours. In fact I am not interested in correcting anything at all. My interest is just to discuss well-based and well fundamented opinions about something, even if drastically different points of view might emerge from those discussions. I never turn down a good fight of ideas.
So I am not going to “correct” any of your statements or "beliefs" but rather give some more data about the EH101. You will know where they fit.
- Engine and transmission limits with one engine off still make available more then 75% of the total power to the pilots.
- It is allowed and indeed a very common procedure to turn off the right engine (number three) in flight if one wants to increase the endurance from 750 to 1,000 nautical miles or provide for greater loiter time.
- The left engine (number 1) is tied to the auxiliary gear box and does not directly turn the main rotor.
cyclic_fondler
I think it's very easy to pick faults with the EH-101 as it is in use and we are aware of it's real limitations compared to the H-92 which is not in an operational role just yet.
I think we need to wait until there's about 30-40 H92 out there doing various roles before we have some real data and then we can have a real fight!
I think we need to wait until there's about 30-40 H92 out there doing various roles before we have some real data and then we can have a real fight!
On top of that they can be anything provided one can convince the buyer that the manufacturer will be able to make good on his promises. Kind of the Boeing Dreamliner that can be anything until it starts flying...
How come somebody buys 5 billion worth of promises is mind-boggling
The EH 101 is being flown everywhere, was deployed in the Balcans conflict, it is deployed in Iraq in extremely demanding conditions and will be packing soon elsewhere also very hot, very dry and very messy...
The H92 is "deployed" in Sikorsky's drawing board...
Oh BTW I almost forgot one thing:
Follow-up of the NH90 seems to be the HTH - Heavy Transport Helicopter for 70 troops intended to replace the twin engine CH53's in Europe and trying to give a run to Sikorsky's HLH (Heavy Lift Helicopter)... Number of engines they are thinking about ? THREE also !
Can you imagine the amount of payload they are going to loose to those engines ?
Well but this one is still in the "Dreamliner" phase. Not yet for sale.
Last edited by RotorPilot; 31st Jul 2004 at 16:52.
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Again RotorPilot says "You simply do not know what you are talking about." Again without giving any facts.
OK rotorrooter, answer this:
Is the top of the dead man's curve for the EH-101 at MGW at sea level, 15 degrees C at 200 feet? Yes or no?
Is the top of the dead man's curve for the EH-101 at 3,000 feet and 30 degrees C at 400 feet? Yes or no?
Do these figures mean that at 170 feet in a steady hover that EH-101 (with the "extra third engine") will fall and crash if it loses one of its three engines? Yes or no?
Do these figures mean that if the EH-101 is doing a winch rescue under these conditions that it will have to ditch? Yes or no?
I think we are all waiting, RotorPilot. Please answer
OK rotorrooter, answer this:
Is the top of the dead man's curve for the EH-101 at MGW at sea level, 15 degrees C at 200 feet? Yes or no?
Is the top of the dead man's curve for the EH-101 at 3,000 feet and 30 degrees C at 400 feet? Yes or no?
Do these figures mean that at 170 feet in a steady hover that EH-101 (with the "extra third engine") will fall and crash if it loses one of its three engines? Yes or no?
Do these figures mean that if the EH-101 is doing a winch rescue under these conditions that it will have to ditch? Yes or no?
I think we are all waiting, RotorPilot. Please answer
rjsquirrel,
It is difficult to understand where you are going with this; if I were supporting the S92 against the EH101, One Engine Inopertative (OEI) performance would not have been the issue of my choice (for the reason I indicated earlier). However, if you wish to continue with it, it might be fairer to compare graphs for both aircraft.
The HV Diagram is not a graph that is used when examining winching performance - it is too general and therefore of little use. What would normally be used (if engine failure is being considered - which it might not under military conditions) is the OEI HOGE performance graph; the entry point would be (initial) on-task mass.
Even then it is more complex than the HV diagram, as density and wind would have to be taken into consideration. Such graphs usually have temperature and pressure (density altitude) as the constants with drop-down v hover-mass as the trade off. With some missions, there is the opportunity of taking advantage of some of the drop down - so increasing the on-task mass; this would not result in a ditching.
If one were to do these calculations for the EH101 and the S92, it is likely that the EH101 would be nearer to MTOM than the S92.
It is difficult to understand where you are going with this; if I were supporting the S92 against the EH101, One Engine Inopertative (OEI) performance would not have been the issue of my choice (for the reason I indicated earlier). However, if you wish to continue with it, it might be fairer to compare graphs for both aircraft.
The HV Diagram is not a graph that is used when examining winching performance - it is too general and therefore of little use. What would normally be used (if engine failure is being considered - which it might not under military conditions) is the OEI HOGE performance graph; the entry point would be (initial) on-task mass.
Even then it is more complex than the HV diagram, as density and wind would have to be taken into consideration. Such graphs usually have temperature and pressure (density altitude) as the constants with drop-down v hover-mass as the trade off. With some missions, there is the opportunity of taking advantage of some of the drop down - so increasing the on-task mass; this would not result in a ditching.
If one were to do these calculations for the EH101 and the S92, it is likely that the EH101 would be nearer to MTOM than the S92.
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4.1.2.3.2.
In order to reduce the risk of loss of an aircraft in the maritime environment, it is essential that the MH have power plant and flight dynamic capabilities, which include the following features:
a. capability of operating in icing conditions;
b. be multi-engined and have a one-engine-inoperative (OEI) capability sufficient to allow: a safe immediate emergency landing from a 60 ft hover, or, after transition to forward flight, safe recovery to the nearest practical landing site; and
c. to maximize the chances of safely recovering the MH, all gearboxes must be capable of operating for a minimum of 30 minutes after the total loss of all normal lubricating fluid.
The only question is does the aircraft meet the requirements of para B .
there are no extra points for exceeding the requirements .
http://www.forces.gc.ca/admmat/mhp/sor/mhp_sor.doc
Does any one have the equivalant requirement from the original SOR ?.
In order to reduce the risk of loss of an aircraft in the maritime environment, it is essential that the MH have power plant and flight dynamic capabilities, which include the following features:
a. capability of operating in icing conditions;
b. be multi-engined and have a one-engine-inoperative (OEI) capability sufficient to allow: a safe immediate emergency landing from a 60 ft hover, or, after transition to forward flight, safe recovery to the nearest practical landing site; and
c. to maximize the chances of safely recovering the MH, all gearboxes must be capable of operating for a minimum of 30 minutes after the total loss of all normal lubricating fluid.
The only question is does the aircraft meet the requirements of para B .
there are no extra points for exceeding the requirements .
http://www.forces.gc.ca/admmat/mhp/sor/mhp_sor.doc
Does any one have the equivalant requirement from the original SOR ?.
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Widgeon:
Thanks for posting that (and the link); it appears that you are closer to this than we observers - I have one observations and two question:[list=1][*]Item c is far less ambiguous than FAR 29.927(c)(1) and appears to allows less 'interpretation'[*]Does the OEI capability have to be shown at the MAUM?[*]Does a 'safe immediate landing' permit a safe-forced-landing on water (i.e. a ditching)?[/list=1]
Thanks for posting that (and the link); it appears that you are closer to this than we observers - I have one observations and two question:[list=1][*]Item c is far less ambiguous than FAR 29.927(c)(1) and appears to allows less 'interpretation'[*]Does the OEI capability have to be shown at the MAUM?[*]Does a 'safe immediate landing' permit a safe-forced-landing on water (i.e. a ditching)?[/list=1]
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Widgeon
I saw the original SOR and copied it, but I don't have access to it anymore. I even posted this part in the CanadianAviation.com Forum but it was closed down and its no longer online. Otherwise we would have access to the original specs there.
The initial SOR clearly stated as a condition:
"Full survivability with the loss of one engine"
This was the single most important requirement that was watered down (b) to accommodate other helicopters apart from the EH101, in spite of denials from several quarters.
But even with this it was such a close call that it seems it was "necessary" to disqualify the EH101 just to be on the safe side.
Does any one have the equivalent requirement from the original SOR ?.
The initial SOR clearly stated as a condition:
"Full survivability with the loss of one engine"
This was the single most important requirement that was watered down (b) to accommodate other helicopters apart from the EH101, in spite of denials from several quarters.
But even with this it was such a close call that it seems it was "necessary" to disqualify the EH101 just to be on the safe side.
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Huh. Do you really mean that?
To: RotorPilot
If this is the case if you shut down the right engine you will be operating on one engine. There is a clutch in there somwhere.
The left engine (number 1) is tied to the auxiliary gear box and does not directly turn the main rotor.
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If this is the case if you shut down the right engine you will be operating on one engine. There is a clutch in there somewhere.
If you loose one engine you go on operating the other two.
This EH101 has "full survivability with the loss of one engine" and was the only helicopter to fulfill the initial requirements before the... .... hummm... ... "baptism"...
In fact the EH101 fly "twin" in a number of situations as "normal" operations. In case of need the number 3 can be put on line in seconds.
On the ground from cold start to full three engines power 90 seconds...
Jim L....
How many helicopters have a geniune OEI HOGE performance chart at all? Lets see....if we take any multi-engined helicopter in existence....load them to reasonable weights...defined as typical mission weights.....I doubt there are but one or two that might be able to accomplish a OGE Hover after losing one engine...meaning one engine on the 92....two engines left on the 101...two engines on the 53E....one engine left on the CH-47.
All you big iron drivers...drop yer beers...grab yer RFM's...go to the performance sections....calculate your OGE hover weight limits....expressed in percentage of an aircraft that weighs in at 90% of mauw or maum at takeoff at a sealevel...ISA day.......divide the chart weight by the 90% weight...and report the numbers....no wind ....seal level...ISA conditions.....do any pass muster with a 1.0 coeffiecient?
How many helicopters have a geniune OEI HOGE performance chart at all? Lets see....if we take any multi-engined helicopter in existence....load them to reasonable weights...defined as typical mission weights.....I doubt there are but one or two that might be able to accomplish a OGE Hover after losing one engine...meaning one engine on the 92....two engines left on the 101...two engines on the 53E....one engine left on the CH-47.
All you big iron drivers...drop yer beers...grab yer RFM's...go to the performance sections....calculate your OGE hover weight limits....expressed in percentage of an aircraft that weighs in at 90% of mauw or maum at takeoff at a sealevel...ISA day.......divide the chart weight by the 90% weight...and report the numbers....no wind ....seal level...ISA conditions.....do any pass muster with a 1.0 coeffiecient?
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SASless,
You are correct in that it is unusual to see OEI HOGE graphs in other than a European Flight Manual. However, for human external cargo or, in Europe, CAT Hoisting, such performance has to be ensured. (In some countries when conducting SAR it is acceptable not to have such performance during a mission but necessary during hoist training.)
Such graphs are present in the S76C+, AS332 and Bell 412 manuals (even the venerable S61 which we used to use for passenger winching in the Beryl Field) and data is available for the EH101. Unusually, the best performers are the (FAR 27 Appendix C certificated) EC135, A109 and probably the MD902 which are now quite close to OEI HOGE performance in ISA nil wind conditions (it is also expected that the AB139 will provide close to nil drop down in ISA conditions within its published MAUM).
From the Operational Specification shown to us by Widgeon, it would appear that the Canadian aircraft of choice had to be capable of a drop down from the hover of less than 60ft. It is likely that for all reasonable sectors (for short sectors the fuel load could be reduced), arrival at the point where winching had to be commenced with this performance in hand could have been achieved by the EH101 (and hopefully by the S92). (However, it was difficult to establish from the text that Widgeon showed us what the required mass would have to be.)
Such performance has always been required for passenger transfer in Europe - and some other countries in the world.
You are correct in that it is unusual to see OEI HOGE graphs in other than a European Flight Manual. However, for human external cargo or, in Europe, CAT Hoisting, such performance has to be ensured. (In some countries when conducting SAR it is acceptable not to have such performance during a mission but necessary during hoist training.)
Such graphs are present in the S76C+, AS332 and Bell 412 manuals (even the venerable S61 which we used to use for passenger winching in the Beryl Field) and data is available for the EH101. Unusually, the best performers are the (FAR 27 Appendix C certificated) EC135, A109 and probably the MD902 which are now quite close to OEI HOGE performance in ISA nil wind conditions (it is also expected that the AB139 will provide close to nil drop down in ISA conditions within its published MAUM).
From the Operational Specification shown to us by Widgeon, it would appear that the Canadian aircraft of choice had to be capable of a drop down from the hover of less than 60ft. It is likely that for all reasonable sectors (for short sectors the fuel load could be reduced), arrival at the point where winching had to be commenced with this performance in hand could have been achieved by the EH101 (and hopefully by the S92). (However, it was difficult to establish from the text that Widgeon showed us what the required mass would have to be.)
Such performance has always been required for passenger transfer in Europe - and some other countries in the world.
Last edited by Mars; 2nd Aug 2004 at 06:17.
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On top of everything, the EH101 has "eagle-eyes" something the others don't have 
Four young New Brunswickers were considered lucky to be alive Sunday after spending 17 hours adrift at sea overnight in an inflatable dinghy.
The two young men and two young women, aged 16 to 22, were spotted by the eagle-eyes of a Cormorant helicopter team early Sunday afternoon and were then rescued.
Missing teens plucked from rough seas
Four young New Brunswickers were considered lucky to be alive Sunday after spending 17 hours adrift at sea overnight in an inflatable dinghy.
The two young men and two young women, aged 16 to 22, were spotted by the eagle-eyes of a Cormorant helicopter team early Sunday afternoon and were then rescued.
Missing teens plucked from rough seas
Rotor pilot - it's called 'Search and Rescue' - you search for someone using your eyes/TV/Flir/radar and then you Rescue them - if this is your great vindication of your argument for the superiority of the 101 then I hate to disappoint you but the Whirlwind was capable of doing exactly this 40 years ago!
However in the finest traditions of a man losing an argument, you choose to deflect the direction of the argument, either by brining in random stories such as the one above or by making personal attacks on the other parties.
If I choose to contradict you then it may be because I think most of your posts are misleading and extremely biased eg' Engine and transmission limits with one engine off still make available more then 75% of the total power to the pilots.' Does this mean that 75% of the power available from the remaining 2 engines is available (endorsing my comments) or that 75% of the total power from 3 engines is available from the other 2?
'The left engine (number 1) is tied to the auxiliary gear box and does not directly turn the main rotor.' So is this the weak link? can the auxiliary gearbox not handle the full power of the RTM322 and therefore not transmit it to the rotor?
Some facts, not rhetoric would be nice but I think I'll have to ring our Merlin Sqn and get some proper information.
However in the finest traditions of a man losing an argument, you choose to deflect the direction of the argument, either by brining in random stories such as the one above or by making personal attacks on the other parties.
If I choose to contradict you then it may be because I think most of your posts are misleading and extremely biased eg' Engine and transmission limits with one engine off still make available more then 75% of the total power to the pilots.' Does this mean that 75% of the power available from the remaining 2 engines is available (endorsing my comments) or that 75% of the total power from 3 engines is available from the other 2?
'The left engine (number 1) is tied to the auxiliary gear box and does not directly turn the main rotor.' So is this the weak link? can the auxiliary gearbox not handle the full power of the RTM322 and therefore not transmit it to the rotor?
Some facts, not rhetoric would be nice but I think I'll have to ring our Merlin Sqn and get some proper information.
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Crab,
You are dead right to check elsewhere. While it has quite good OEI characteristics, the EH-101 has a fairly small One Engine Inoperative hover envelope, in that if it loses one engine, it cannot maintian the hover unless it is well below MGW, something to the tune of 5000 lbs lost payload.
RotorPilot's idea that it has "full servicability" with one engine shut down is simply absurd, and countered by the EH-101 brochures, which state otherwise, and its flight manual which provides a substantial H-V avoid area, and a rather large Cat A landback distance.
The reason why the MHP requirement was changed to state that a safe landing must be made after engine failure is that no helicopter could enter the OGE hover on the MHP mission, as required, and either maintain the hover after an engine failure, nor could it fly away from the engine failure. The adverts presented by one side's marketing organization (and perhaps written by Mr. RotorPilot, if my suspicions are correct!) were unfortunately not in agreement with the flight manual!
As RotorPilot has refused to answer the simple questions Mr. Squirell has posed to him, perhaps a Merlin or Cormorant pilot could do so.
You are dead right to check elsewhere. While it has quite good OEI characteristics, the EH-101 has a fairly small One Engine Inoperative hover envelope, in that if it loses one engine, it cannot maintian the hover unless it is well below MGW, something to the tune of 5000 lbs lost payload.
RotorPilot's idea that it has "full servicability" with one engine shut down is simply absurd, and countered by the EH-101 brochures, which state otherwise, and its flight manual which provides a substantial H-V avoid area, and a rather large Cat A landback distance.
The reason why the MHP requirement was changed to state that a safe landing must be made after engine failure is that no helicopter could enter the OGE hover on the MHP mission, as required, and either maintain the hover after an engine failure, nor could it fly away from the engine failure. The adverts presented by one side's marketing organization (and perhaps written by Mr. RotorPilot, if my suspicions are correct!) were unfortunately not in agreement with the flight manual!
As RotorPilot has refused to answer the simple questions Mr. Squirell has posed to him, perhaps a Merlin or Cormorant pilot could do so.
Iconoclast
Join Date: Sep 2000
Location: The home of Dudley Dooright-Where the lead dog is the only one that gets a change of scenery.
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Let's try ity one more time
To: RotorPilot
The Auxiliary gearbox is not mounted between the No. 1 engine and anything else. The Aux gearbox is mounted in front of the main transmission and on the ground is powered by No. 1 engine. There are two drive shifts that power the Aux gearbox and when No. 1 is driving on the ground the second shaft is isolated by a freewheeling unit preventing the main transmission from being back driven. As I said there must be a clutch that allows No.1 to run without powering the main rotor.
Nope. This is not the H92... it has three engines and one of them has an "auxiliary gear box" in between.
The left engine (number 1) is tied to the auxiliary gear box and does not directly turn the main rotor.