DonaldM said:
Are there advantages in a heavy lift helicopter moving from a main rotor/anti-torque tail rotor configuration to a tandem rotor configuration?

A larger margin for CG ?
 
With a twin rotor, engine power goes to both rotors for lift; with a single rotor, the anti-torque tail rotor draws power but contributes little or no lift. On the other hand, single rotor designs (for the same approximate design point) are generally somewhat smaller, lighter and have a smaller ground footprint. (This is a gross simplification). As with everything in engineering, there's trade-offs between the two layouts.
 
Boeing Eurocopter Future Transport Helicopter (FTH) on display at ILA 2010.

Source:
http://www.defence.pk/forums/military-forum/103063-bidders-prepare-natos-fth-program.html
 

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aim9xray said:
With a twin rotor, engine power goes to both rotors for lift; with a single rotor, the anti-torque tail rotor draws power but contributes little or no lift. On the other hand, single rotor designs (for the same approximate design point) are generally somewhat smaller, lighter and have a smaller ground footprint. (This is a gross simplification). As with everything in engineering, there's trade-offs between the two layouts.
Twins are also less susceptible to issues of wind direction. Many single rotor have control authority issues with higher winds in cross wind and down wind conditions (landing, hover work).
 
Boeing Eurocopter Future Transport Helicopter (FTH).

Source:
http://www.whq-forum.de/invisionboard/index.php?showtopic=26758&mode=threaded&pid=1102158
 

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DonaldM said:
Are there advantages in a heavy lift helicopter moving from a main rotor/anti-torque tail rotor configuration to a tandem rotor configuration?

Probably the main advantage for Eurocopter in going to tandem is they don't have to design it. They have partnered up with Boeing so will have their tandem tech. But back in 2004 when they were looking at their own super-sized NH90 for the HTH they would have had to design the whole lot from scratch and all that EADS money went on buying BAe out of Airbus.
 
I am of the opinion that the only way the HLH effort will gain traction is if there is interest across the pond. The US has identifed a requirement for heavy lift (beyond CH-47). Of course they will have to show benefit over the CH-53K which will be in production sooner. By "benefit" I mean cheaper.
 
An older document from 2007 about HTH requirements.
 

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yasotay said:
I am of the opinion that the only way the HLH effort will gain traction is if there is interest across the pond. The US has identifed a requirement for heavy lift (beyond CH-47). Of course they will have to show benefit over the CH-53K which will be in production sooner. By "benefit" I mean cheaper.

I thought that the point of the Eurocopter HTH/FTH project was that existing transport helicopters weren't big enough to carry the current generation of fighting vehicles?
 
DonaldM said:
yasotay said:
I am of the opinion that the only way the HLH effort will gain traction is if there is interest across the pond. The US has identifed a requirement for heavy lift (beyond CH-47). Of course they will have to show benefit over the CH-53K which will be in production sooner. By "benefit" I mean cheaper.

I thought that the point of the Eurocopter HTH/FTH project was that existing transport helicopters weren't big enough to carry the current generation of fighting vehicles?
I think you are correct. As pointed out by the file Racer attached there is a need by NATO for an even larger cabin than is currently in development with the 53K. However many would argue that most of the initial expense in rotorcraft is the development of the dynamic components (drive system, rotors, engines) and that the fuselage is less expensive to develop. I would not be surprised to see Sikorsky propose a CH-53K (Block II) that takes base 53K components and puts them on a different fuselage, with modification for higher loads. That would imply (not necessarily true) less cost of development than would a completely new tandem.

With western economic circumstance being what they are, with no quick turn around in sight, I would expect a very challenging environment to development of new larger helicopter. From the perspective of those who have to make very difficult funding decisions; a) no compelling demonstration of a critical failure due to lift requirement has been demonstrated b) there is a funded rotorcraft development in progress that meets many of the projected requirements that, at potentially less cost, could be modified to meet more of the perceived shortfalls.

While a new heavy tandem might best meet shortfalls, financial constraints make "best" come in a distant second to "good enough".
 
Cross-section of Eurocopter HTH circa 2007.

Source:
http://www.whq-forum.de/invisionboard/index.php?showtopic=26758
 

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I presume that France and Germany passed on a Mil Mi-26T-based solution for the Future Transport Helicopter (FTH) program. The Mil Mi-26T would require new engines and avionics and a reduction of crew from five to three to meet French requirements. Development costs were expected to be shared with Russia.

Source:
http://www.defense-aerospace.com/cgi-bin/client/modele.pl?prod=85703&session=dae.29327342.1189085529.jJZem38AAAEAAEf2kyYAAAAb&modele=feature#
 
The Mi-26 is used in western Europe relatively often on charter contracts, for tasks overcharging
the Mi-8. But that we'll ever see a Mi-26 derivative in French or German military markings, to my
opinion is as probable, as the An-70 as the new European heavy transport. But that won't rule out a
co-operation between Mil and say Eurocopter for a westernised version for the export market, of
course.
 
Is the Future Transport Helicopter (FTH) still a project between Eurocopter, err... Airbus Helicopters, and Boeing? Or will France and Germany join JMR-Heavy?
 
The Future Transport Helicopter (FTH) is derived from proven CH-47 technology — grown to meet worldwide multimission demands. As of 2008, Boeing is exploring industrial collaboration with European industry.
 

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The US and Europe should be builting the above referenced HLHs both tandem and single rather than the same old Ch-53K(k is better but quite compromise from what could and should have been built) and 47s.
 
@jsport While I absolutely agree with you philosophically, I suspect that the Europeans are not seeing much profitability in the significant R&D effort to bring one or two large helicopters to fruition. To my knowledge Super Frelon was the last "heavy" designed, and built in Europe. Although one might argue that EH-101 might count (?). Not surprising to see interest in FVL is generating a means to get into the high speed regime with less investment. Likely to be a real factor in post COVID era.
 
As the 6th fighter should have been in service in the early 2000s, here we are in the 2020 and actual VTOL operational implementation is appallingly embarassing in the West. Twittling w/ incremental improvemnts.
 
@jsport While I absolutely agree with you philosophically, I suspect that the Europeans are not seeing much profitability in the significant R&D effort to bring one or two large helicopters to fruition. To my knowledge Super Frelon was the last "heavy" designed, and built in Europe. Although one might argue that EH-101 might count (?). Not surprising to see interest in FVL is generating a means to get into the high speed regime with less investment. Likely to be a real factor in post COVID era.

Especially when you consider how long it has taken them to get the 609 this far.
 

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