Robinson R55? (Merged)
Dave,
I agree with your point in principle but these engines have such short overhaul lives by virtue of the extreme rpm's that they operate at they would only really be ECONOMICALLY viable for experimental aircraft where they will only do a couple of hundred hours total time. For a commercial application then the overhaul costs must be considered. Also 2-stroke engines typically have poor fuel consumption so what you gain in reduced engine weight you loose in additional fuel weight. I have got the data on these engines somewhere, I think a typical SPC for hirth engines is about 0.65 lb/hphr, therefore that 102hp for the four cylinder engine is going to cost you 11 US/Gal/hr and 30kg in fuel weight per hour of endurance required. The lycoming will operate at 0.4 lb/hphr giving 6.8 US Gal/hr and 18.5kg in weight per hour. Therefore, we have to carry 12.5kg per hour extra fuel.
Based on a 3hr mission:
2 Hirth C32 (120hp max together) each 32kg = 64kg
3 hrs of fuel 90kg (@ 102hp)
Total = 154kg
Lycoming O-235 (118hp max) @ 99kg
3 hrs of fuel 55kg (@ 102hp)
Total =154kg
So there is not a weight saving in this case, you'll burn more fuel AND loads of OIL. Furthermore, given the demanding duty cycle of helicopters after 500hrs or so those screaming Hirths will need rebuilding! Cost cost cost!
I'm the first to criticise the Lycoming engines as they are too heavy for helicopters really....but with current available engine options they are the best that's available for the price. Especially the US were fuel is so b100dy cheap!
CRAN
I agree with your point in principle but these engines have such short overhaul lives by virtue of the extreme rpm's that they operate at they would only really be ECONOMICALLY viable for experimental aircraft where they will only do a couple of hundred hours total time. For a commercial application then the overhaul costs must be considered. Also 2-stroke engines typically have poor fuel consumption so what you gain in reduced engine weight you loose in additional fuel weight. I have got the data on these engines somewhere, I think a typical SPC for hirth engines is about 0.65 lb/hphr, therefore that 102hp for the four cylinder engine is going to cost you 11 US/Gal/hr and 30kg in fuel weight per hour of endurance required. The lycoming will operate at 0.4 lb/hphr giving 6.8 US Gal/hr and 18.5kg in weight per hour. Therefore, we have to carry 12.5kg per hour extra fuel.
Based on a 3hr mission:
2 Hirth C32 (120hp max together) each 32kg = 64kg
3 hrs of fuel 90kg (@ 102hp)
Total = 154kg
Lycoming O-235 (118hp max) @ 99kg
3 hrs of fuel 55kg (@ 102hp)
Total =154kg
So there is not a weight saving in this case, you'll burn more fuel AND loads of OIL. Furthermore, given the demanding duty cycle of helicopters after 500hrs or so those screaming Hirths will need rebuilding! Cost cost cost!
I'm the first to criticise the Lycoming engines as they are too heavy for helicopters really....but with current available engine options they are the best that's available for the price. Especially the US were fuel is so b100dy cheap!
CRAN
Robinson R55 - News just in!
Following the earlier discussions on Diesel Robinsons i've have been and done a little research on the current efforts to re-engine Mr Robinsons machines and found this on another forum...
[Quote] When I was at the factory the begining of the month Frank was hinting about a different powerplant for the newer Robinson model.
Some have mentioned Zoche's before. They have some awesome performance specs. www.zoche.de Pat at the factory mentioned Zoche calls Frank about once a week telling him "certifcation is soon" Of course if you have been following Zoche, you know his major problem is that he is a perfectionist and can't settle on a design.
With this engine, you would get more then 200 lbs more payload, 30% more range, and who knows what the HIGE altitude would climb too. They are suppose to produce SL power up to 24,000 feet.
-------------------------------------------------------------------------------------------------------------------------
So it now looks possible that the next helicopter out of the stable will be a 5 seat growth version of the R44 power by a Zoche 300 hp diesel.
The fuel savings in the UK alone would amount to £41 less per hour including the increased gross weight!
High Performance (even at altitude)
Long Range
Improved Payload
Hydraulics
Low Purchase Price
...it'll be a hell of a machine.
Is there anybody out there that knows anymore?
CRAN
[Quote] When I was at the factory the begining of the month Frank was hinting about a different powerplant for the newer Robinson model.
Some have mentioned Zoche's before. They have some awesome performance specs. www.zoche.de Pat at the factory mentioned Zoche calls Frank about once a week telling him "certifcation is soon" Of course if you have been following Zoche, you know his major problem is that he is a perfectionist and can't settle on a design.
With this engine, you would get more then 200 lbs more payload, 30% more range, and who knows what the HIGE altitude would climb too. They are suppose to produce SL power up to 24,000 feet.
-------------------------------------------------------------------------------------------------------------------------
So it now looks possible that the next helicopter out of the stable will be a 5 seat growth version of the R44 power by a Zoche 300 hp diesel.
The fuel savings in the UK alone would amount to £41 less per hour including the increased gross weight!
High Performance (even at altitude)
Long Range
Improved Payload
Hydraulics
Low Purchase Price
...it'll be a hell of a machine.
Is there anybody out there that knows anymore?
CRAN
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I would be very surprised. Zoche have been to all of the shows for many years...still no certified engine though. I don't know anyone who has flown anything, fixed wing or rotary with a Zoche engine.
Ian
Ian
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2,3 or 4
Hopefully they will put a 3 or 4 blade rotor on it and with that they will have a really fantastic machine. Hell, if they put a three blade rotor on the R-22 they would have a really fantastic machine.
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I'm sorry if this has been covered, (I'm a bit trashed today) ...
If FR did place a small turbine into a 44, or even a 22, how much larger would the associated fuel tanks be to get useful range out of it? Would the standard tanks be enough? (IMO no)
If FR did place a small turbine into a 44, or even a 22, how much larger would the associated fuel tanks be to get useful range out of it? Would the standard tanks be enough? (IMO no)
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I wish your dreams about the Zoche come true!
He is in Oshkosh (EAA Air Venture) every year, but the Experimental Comunity has given up to see a Zoche in an aircraft ever!
He had some trouble with a "stolen" patent (stolen from him....) in the states and to resolve this issue took a lot of time, but one can still hope!!
Check out this engine, it is awsome in design and simplicity.
Zoches "problem" is, that he want´s to make it so perfect, that the only thing you can do is to change the oil! Anything else would have to be done at the factory or authorized repairstation.
He wants to build the engine so, that you actually can not open it without destroying it, permanently eliminating it from aircraft service!
No repairs or overhauls, but factory new replacement for an overhaul price is/was the idea. The overhauled Ex-aircraft engines will be used in non-aviation applications (waterpumps for fire departements, commercial compressors, etc.)
I really hope we will see this engine in action before fossil fuel becomes obsolete!
3top
He is in Oshkosh (EAA Air Venture) every year, but the Experimental Comunity has given up to see a Zoche in an aircraft ever!
He had some trouble with a "stolen" patent (stolen from him....) in the states and to resolve this issue took a lot of time, but one can still hope!!
Check out this engine, it is awsome in design and simplicity.
Zoches "problem" is, that he want´s to make it so perfect, that the only thing you can do is to change the oil! Anything else would have to be done at the factory or authorized repairstation.
He wants to build the engine so, that you actually can not open it without destroying it, permanently eliminating it from aircraft service!
No repairs or overhauls, but factory new replacement for an overhaul price is/was the idea. The overhauled Ex-aircraft engines will be used in non-aviation applications (waterpumps for fire departements, commercial compressors, etc.)
I really hope we will see this engine in action before fossil fuel becomes obsolete!
3top
Last edited by 3top; 24th Jul 2003 at 09:34.
Senis Semper Fidelis
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Experimental Derv R22
All this talk/reading has promted me to start my own experiment, I have an old Perkins Square Four at the back of my tractor shed, and given that I am of the old farming type I am nearly sure that it will fit into the engine bay of the R22, any way if I can damp out the vibrations and get it rigged I will let you all know!
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Cran,
"Just had some interesting news back from the man himself! This is at least three years away. So don't be rushing out to buy easy start just yet!"
The man himself? Are you referring to Lu Zuckerman?
"Just had some interesting news back from the man himself! This is at least three years away. So don't be rushing out to buy easy start just yet!"
The man himself? Are you referring to Lu Zuckerman?
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New Robinson helicopter
http://www.ukintpress.com/engineoftheyear/ieoty.html
Powerful, lightweight, mechanically simple. Could this be the engine for a new Robinson? The RX22!
Powerful, lightweight, mechanically simple. Could this be the engine for a new Robinson? The RX22!
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Robinson R44/D - fact or spelling mistake
Just looking at the list of aircraft on display in the london air show
www.londonairshow.co.uk
and I notice that there's a Robinson R22 and Robinson R44/D !!!
I suspect that this is just a spelling mistake unless somebody has been on the factory safety course recently and heard any rumours !!!!
www.londonairshow.co.uk
and I notice that there's a Robinson R22 and Robinson R44/D !!!
I suspect that this is just a spelling mistake unless somebody has been on the factory safety course recently and heard any rumours !!!!