pavlin
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Which Engines Are The Most Effiecien7?

Thu Apr 13, 2006 9:38 pm

I know they are pretty much the same, but I heard that RR powered 747 flies longer routes. But CF6 seem most popular large engine family. What about engines on 767, 777 and A330. On a A340-600 there is no real comparison. In small engine IAEV2500 are slightly more efficient than CFM56 but have higher maintenance cost.
 
Airmech56
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 1:29 am

As far as I know, and Im not 100% absolute sure, but I do believe that it's the GE90-94B (B777) .
 
Dougloid
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 1:55 am

I think one needs some information about specific fuel consumption (SFC) to arrive at a good answer here.

The Wright Turbo Compound had a SFC of about 0.36 in cruise, which is about as good as it will ever get in a recip.
If you believe in coincidence, you haven't looked close enough-Joe Leaphorn
 
phollingsworth
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 2:33 am

Quoting Airmech56 (Reply 1):
As far as I know, and Im not 100% absolute sure, but I do believe that it's the GE90-94B (B777) .

On the 777-200/300 the GE90s have the best mission fuel-burn performance, all else remaining equal. However, they are significantly heavier than either the PW or RR engines. This means that for shorted mission profiles the RR may actually be the more profitable engine. Also the GE90-94B is really not sufficient as there are many -90B and -92Bs that have the same bill of materials and the same cruise operating parameters.
 
kaddyuk
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 5:53 am

Quoting Pavlin (Thread starter):
But CF6 seem most popular large engine family.

This is probably due to the fact that the CF6-80C2 series (the one that fits a jumbo) also fits MD-11's and B767's as well... Making it easier for airlines (like KLM for example who operate all 3 types) to run one type of engine. I do belive the difference between the engines is the EEC used to control the engine differs from aircraft to aircraft.
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airxliban
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 6:25 am

IIRC:

1. On the 757-200, the RB211 is both the more powerful engine as well as the more efficient one.

2. On the 767-300, the CF6 is the more economical engine. The RB211 is heavier, has a higher pylon weight, consumes more fuel and produces less max thrust.

3. On a 747-400, the PW4056 is more efficient than the RB211 but I don't know how the CF6 compares.

4. Not sure how any of the A330 powerplants stack up against each other, but the Trent seems to have gained a more significant market share than the RB211 did on the 767 and 747.

Quoting Pavlin (Thread starter):
but I heard that RR powered 747 flies longer routes

RB211 powered 747-400 has the shortage range (marginally) when compared against the CF6 and PW4056.

Quoting Pavlin (Thread starter):
On a A340-600 there is no real comparison

On the A340-600 there is only one engine available, is that what you meant?
PARIS, FRANCE...THE BEIRUT OF EUROPE.
 
phollingsworth
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 11:40 am

Quoting AirxLiban (Reply 5):
1. On the 757-200, the RB211 is both the more powerful engine as well as the more efficient one.

Not entirely triue. The RB211-535E4-B-75 and C-37 both have a certified maximum take-off thrust of 42,540 lbs, a max continuous thrust of 35,205 lbs, and a dry weight of 7,603 lbs. This compares to the PW2040 which has a max take-off thurst of 40,900 lbs, max continuous of 34,640 lbs, and a dry weight of 7,300 lbs. So the RR has more thrust but also weighs more. Boeing could have certified the -200 with the PW2043 if a customer had asked for it.

Looking at Boeing's aircraft compatibility charts for the 757-200 the RR powered a/c with a MTOW of 256,000 lbs reaches maximum fuel volume at 178,000 lbs OEW+Payload. This gives it a still air range of 3,500 nm. The PW reaches max fuel volume at the same OEW+Payload (not a function of engine weight) but has a still air range of 3,800 nm. This indicates that the PW has better fuel burn performance.
 
pavlin
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 5:56 pm

Quoting Phollingsworth (Reply 6):
. On the 757-200, the RB211 is both the more powerful engine as well as the more efficient one.

The PW has gretaer range, but a lot of American airlines prefer RR
 
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kc135topboom
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 9:58 pm

Quoting Pavlin (Reply 7):
The PW has gretaer range, but a lot of American airlines prefer RR

AA, CO, and TZ fly the B-757s with RR RB-211s. While DL, NW and UA fly their B-757s with PW-2040s. UPS flys there B-757 with both engine types.
 
airxliban
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RE: Which Engines Are The Most Effiecien7?

Fri Apr 14, 2006 10:23 pm

Quoting KC135TopBoom (Reply 8):
AA, CO, and TZ fly the B-757s with RR RB-211s

AA has ex-TW PW birds as well and you forgot to mention that US and HP both fly 757-200s with RB211s exclusively.
PARIS, FRANCE...THE BEIRUT OF EUROPE.
 
AirbusA6
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RE: Which Engines Are The Most Effiecien7?

Mon Apr 24, 2006 12:45 pm

Quoting Pavlin (Reply 7):
The PW has gretaer range, but a lot of American airlines prefer RR

The RB211-535 was a LOT more reliable than the PW2000, the lower maintenance costs won it many orders despite the PW2000 being more fuel efficient.
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tepidhalibut
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RE: Which Engines Are The Most Effiecien7?

Mon Apr 24, 2006 4:52 pm

Quoting AirbusA6 (Reply 10):
The RB211-535 was a LOT more reliable than the PW2000, the lower maintenance costs won it many orders despite the PW2000 being more fuel efficient.

I believe that the PW2000 is more fuel efficient *when new* (or fully refurbished), but I hear that after a few hundred cycles, that benefit is eliminated. PWs often come off-wing for lack of margin, whereas the RR's usually stay on until they're TimExed.

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