Robinson R44
D3, you are asking people to decide your fuel burn for you. Nobody can tell you how much fuel your R44 is going to burn because the variables are so many. That is why Frank doesn't publish the numbers.
Just plan at 60ltrs and do a fuel burn calculation.
Did they not teach you this in your training?
Just plan at 60ltrs and do a fuel burn calculation.
Did they not teach you this in your training?
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As the Raven I will in the next weeks be replaced by a R44 II
h-r
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Interesting
some guys make you feel ridiculus, explain what to do, but dont answer the question
Maybe I should add : this is your captain speaking, I am not certain if we will get there, but be reassured, i know how to add even how to divide, and i have brought a spare broomstick with me, so not to worry...
some guys answer
thanks guys who answered, the tendency is clear lets worry about the decimals later.
d3
some guys make you feel ridiculus, explain what to do, but dont answer the question
Maybe I should add : this is your captain speaking, I am not certain if we will get there, but be reassured, i know how to add even how to divide, and i have brought a spare broomstick with me, so not to worry...
some guys answer
thanks guys who answered, the tendency is clear lets worry about the decimals later.
d3
Last edited by delta3; 21st Apr 2005 at 22:35.
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rotordog
all companies that i know of use 60ltrs per hr but the current one uses 65 for float equipped heli's. i cant understand why u would use more fuel when its float equipped as you still only pull the same mp, more fuel per mile but wont be more fuel per hour i dont recon??
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Billywizz
After some more research I decided to have my 58 l/hr R44-I planning rate increased to 62 for the R44-II in the same circumstances, so slightly above 16, for a typical 3 POB flight.
I'll find out soon what the consumptions are. Of course I agree with those ppruners that state that consumption depends on lots of things, but in the 1600 hrs I did with the R44-I, 58 for my 'flying style', that is keeping between 21 and 22" worked out all right. That sometimes also implied going to FL 65 at max power and consuming more, but this being offset by higher ground speeds, so that actual flight time was shorter. My R44-I in fact kind of liked flying there if nice laminar air (or is it the pilot..).
I'am consulting now some official Lycoming performance and consumption charts. I also found out that some local operators warned their CPL's to take greater provisions with the R44-II, because apparently some had chairman of the bored experiences and didn't quite make it to the planned destinations, to the unliking of the passengers (and the boss..).
As an engineer I am surprised of this higher consumption : slightly heavier, more average cord or injection. The latter would really disappoint me if you see what common rail direct injection can achieve (not really the same, but still..)
d3
After some more research I decided to have my 58 l/hr R44-I planning rate increased to 62 for the R44-II in the same circumstances, so slightly above 16, for a typical 3 POB flight.
I'll find out soon what the consumptions are. Of course I agree with those ppruners that state that consumption depends on lots of things, but in the 1600 hrs I did with the R44-I, 58 for my 'flying style', that is keeping between 21 and 22" worked out all right. That sometimes also implied going to FL 65 at max power and consuming more, but this being offset by higher ground speeds, so that actual flight time was shorter. My R44-I in fact kind of liked flying there if nice laminar air (or is it the pilot..).
I'am consulting now some official Lycoming performance and consumption charts. I also found out that some local operators warned their CPL's to take greater provisions with the R44-II, because apparently some had chairman of the bored experiences and didn't quite make it to the planned destinations, to the unliking of the passengers (and the boss..).
As an engineer I am surprised of this higher consumption : slightly heavier, more average cord or injection. The latter would really disappoint me if you see what common rail direct injection can achieve (not really the same, but still..)
d3
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Well, I don't fly the R44 but this got me thinking. Does this really matter for you because of the 100lbs increase in MTOW in the R44II over the R44I and therefore you should be able to carry a little more fuel and some more happy paying load?
As I said I don't fly the R44 and haven't seen the W&B for it.
I realize that 2 USG/hr adds to the cost but does it matter that much?
This reminds me of a friend of mine who a few years back was buying a Rolls Royce and since he is from an Icelandic farm and very curious he asked the Rolls dealer how much fuel it consumes. The dealer told my friend that if he had to worry about the fuel consumption he wouldn't have anything to do with having a Rolls
As I said I don't fly the R44 and haven't seen the W&B for it.
I realize that 2 USG/hr adds to the cost but does it matter that much?
This reminds me of a friend of mine who a few years back was buying a Rolls Royce and since he is from an Icelandic farm and very curious he asked the Rolls dealer how much fuel it consumes. The dealer told my friend that if he had to worry about the fuel consumption he wouldn't have anything to do with having a Rolls
Last edited by Heli-Ice; 24th Apr 2005 at 00:54.
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Heli-Ice
What matters for me is max range, both machines can always be fully topped with my payloads (3-4 POB not all heavy, plus luggage). In a number of flights (in the 500NM range) the difference may require extra refueling stops . Alternatively you could slow down and go for max efficiency, but this doesn't work well with headwinds (max efficiency speed goes up again)
In the Alps on the otherhand the II will be able to carry full loads (4 instead of 3 POB), which the R44-I couldn't with some long range fuel amount on board.
d3
In the Alps on the otherhand the II will be able to carry full loads (4 instead of 3 POB), which the R44-I couldn't with some long range fuel amount on board.
d3
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I'm with you delta3.
Does anyone here know why the R44 manual doesn't have any fuel tables?
p.s. I just had to put my friends Rolls story in there to put a smile on your face.
Does anyone here know why the R44 manual doesn't have any fuel tables?
p.s. I just had to put my friends Rolls story in there to put a smile on your face.
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R44 Raven I vs. Raven II
Can anybody give us a reasonable comparison between these two ships from a practical operational point of view? Does anyone have realistic experience on operating costs, idiosyncracies, performance differences, etc, that are different from the "sales figures" or the Flight Manual?
Thanks.....
Thanks.....
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Leaning the R44 Engine
The R44 POH states
Fair comment. The fixed wing population have some advantages here with the prop connected to the engine.
However, I read Jennifer Murray's book (Now Solo) about flying the R44 around the world last night and there were several mentions of flying the engine "lean".
What experience do members of the panel have of leaning the O-540 (normally aspirated) engine on the R44 and should this practice be encouraged in controlled situations?
h-r
CAUTION
Inflight leaning with engine mixture control is not recommended. Engine stoppage may result as there is no propellor to keep engine turning should overleaning occur.
Inflight leaning with engine mixture control is not recommended. Engine stoppage may result as there is no propellor to keep engine turning should overleaning occur.
However, I read Jennifer Murray's book (Now Solo) about flying the R44 around the world last night and there were several mentions of flying the engine "lean".
What experience do members of the panel have of leaning the O-540 (normally aspirated) engine on the R44 and should this practice be encouraged in controlled situations?
h-r
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The problem with leaning the engine in an R44 is, I think, the lack of a vernier style (screw) fuel control to finetune the mixture. Early models of the R22 did have a vernier mixture and pilots could and would lean the engine. I guess the potential for liability made Frank Robinson change to the push/pull style mixture and the admonition in the POH not to lean in flight. However, it still can be done, provided one is very careful.
The R44 is a slightly different kettle of fish than the R22 when discussing leaning procedures as the R22 is considered a low power engine.
However - both engines can be leaned - from rich to normal - prior to flight.
I flew R22's using this procedure for quite a few K hours.
This procedure usually gave me at least another inch of MAP safety margin up my sleeve by reducing the power required for a particular task.
Please read my link to the R22 procedure and then maybe some one can follow it up for the R44.
http://brumbyhelicopters.com.au/lean2normal.htm
Tc
However - both engines can be leaned - from rich to normal - prior to flight.
I flew R22's using this procedure for quite a few K hours.
This procedure usually gave me at least another inch of MAP safety margin up my sleeve by reducing the power required for a particular task.
Please read my link to the R22 procedure and then maybe some one can follow it up for the R44.
http://brumbyhelicopters.com.au/lean2normal.htm
Tc
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To lean in a controlled way it is best to have a vernier mixture adjustment and a multicylinder engine monitor such as the JPI or EI instruments. It is very doubtful that a carburettor Lycoming can be efficiently leaned as the mixture distribution to each cylinder is appalling. The risk is that it is possible to push the leanest cylinder into overheating. Robinsons only have one head temp probe which may not be on the hottest/leanest cylinder. It is possible to cause damage by overheating without detonation. 400 deg F should be considered a practical maximum cruising head temp and it is easy to exceed this by leaning.
Injected engines are a bit better but unless the injector nozzles are matched to provide the correct flow for each cylinder, overheating one or more cylinders is still possible unless all the head temps are monitored.
Leaning is permitted with Enstroms and I always lean aggressively. It is possible to drop the fuel consumption from 14 gph to 10 and run with lower cylinder head temps. I generally run the hottest head at 350-360 deg F. I use the techniques described by John Deakin. (see below)
With a properly set up injection system it is possible to lean safely and efficiently. It is almost impossible to stop an engine by overleaning as the power drop off alerts the pilot in good time.
Leaning is also demanding of pilot attention to do it correctly.
The risk is the brainstorm when returning to full rich, when one pulls the knob instead of pushing it. I know - I have done it. The engine stops.
Robinsons are not equipped for leaning and to do so without the appropriate instrument/control is fraught with pitfalls. The Raven2 could be modified for safe and successful in flight leaning but unless it was, I wouldn't do it.
I would think a properly modified, leaned Raven 2 would cruise on 12 U.S. gallons per hour. Was Jennifer Murrays aircraft modified?
John Deakin has written lots on this subject and before anyone considers leaning a Robbie, a bit of time reading these articles is recommended.
http://www.avweb.com/news/columns/182544-1.html
Injected engines are a bit better but unless the injector nozzles are matched to provide the correct flow for each cylinder, overheating one or more cylinders is still possible unless all the head temps are monitored.
Leaning is permitted with Enstroms and I always lean aggressively. It is possible to drop the fuel consumption from 14 gph to 10 and run with lower cylinder head temps. I generally run the hottest head at 350-360 deg F. I use the techniques described by John Deakin. (see below)
With a properly set up injection system it is possible to lean safely and efficiently. It is almost impossible to stop an engine by overleaning as the power drop off alerts the pilot in good time.
Leaning is also demanding of pilot attention to do it correctly.
The risk is the brainstorm when returning to full rich, when one pulls the knob instead of pushing it. I know - I have done it. The engine stops.
Robinsons are not equipped for leaning and to do so without the appropriate instrument/control is fraught with pitfalls. The Raven2 could be modified for safe and successful in flight leaning but unless it was, I wouldn't do it.
I would think a properly modified, leaned Raven 2 would cruise on 12 U.S. gallons per hour. Was Jennifer Murrays aircraft modified?
John Deakin has written lots on this subject and before anyone considers leaning a Robbie, a bit of time reading these articles is recommended.
http://www.avweb.com/news/columns/182544-1.html
Last edited by Gaseous; 2nd May 2005 at 20:49.
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No specific reference in the book but I think it was a standard Astro (and standard Clipper - float packs) following. They quote 9USG/Hr figures when lean.
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Redeye,
Its some time since I flew an Astro but 9GPH sounds a bit low, but possible. Do you know what speed she was flying at? The best I can get in terms of fuel saving on a really well set up Enstrom is a fuel saving of about 30% from full rich. I should think if you lean a carb 540 to that extent it will get very rough. I have seen 7.5gph in an Enstrom, P1 only at 50mph with minimum weight. 10gph gives me a reasonable cruising speed of 80 and an endurance of 2.5 hours.
Its some time since I flew an Astro but 9GPH sounds a bit low, but possible. Do you know what speed she was flying at? The best I can get in terms of fuel saving on a really well set up Enstrom is a fuel saving of about 30% from full rich. I should think if you lean a carb 540 to that extent it will get very rough. I have seen 7.5gph in an Enstrom, P1 only at 50mph with minimum weight. 10gph gives me a reasonable cruising speed of 80 and an endurance of 2.5 hours.
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From memory from the book they were flying at the 'speed of the slowest man' which would have been the Microlight, so around 60kts IAS.
I guess the air was quite cold as well in Mid Greenland so this may have contributed to good performance.
I guess the air was quite cold as well in Mid Greenland so this may have contributed to good performance.