Pavlin From , joined Dec 1969, posts, RR: Posted (7 years 8 months 2 weeks 12 hours ago) and read 3144 times:
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.
Phollingsworth From United Kingdom, joined Mar 2004, 825 posts, RR: 6 Reply 3, posted (7 years 8 months 2 weeks 7 hours ago) and read 3081 times:
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.
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.
Whoever said "laughter is the best medicine" never had Gonorrhea
Phollingsworth From United Kingdom, joined Mar 2004, 825 posts, RR: 6 Reply 6, posted (7 years 8 months 1 week 6 days 22 hours ago) and read 2974 times:
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.
TepidHalibut From Iceland, joined Dec 2004, 207 posts, RR: 6 Reply 11, posted (7 years 8 months 3 days 17 hours ago) and read 2584 times:
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.