N1120A From United States of America, joined Dec 2003, 25852 posts, RR: 79 Posted (7 years 10 months 2 weeks 3 days 21 hours ago) and read 2387 times:
Ok, a question here for those in fleet planning and the like. Northwest has a pretty well known deal with PW where Pratt pays NW for the significant difference in fuel consumption between the PW2000 and the RB211 on the 753. The question is two fold. First, does Pratt also pay NW for the difference in fuel consumption on the 752 and second, do any other airlines have this arangement?
Mangeons les French fries, mais surtout pratiquons avec fierte le French kiss
PSU.DTW.SCE From United States of America, joined Jan 2002, 6875 posts, RR: 29 Reply 1, posted (7 years 10 months 2 weeks 3 days 21 hours ago) and read 2369 times:
I don't believe this arrangement exists on the 752's.
The reasoning behind this, as at the time, the 753 was only offered with the RR engines, thus NW was the launch customer for the PW 753's, and is the only operator of this type (I believe).
NW initially went with the PW engines on the 752 fleet since they had PW engines on the DC-10-40's at the time and were a happy PW customer.
Gigneil From United States of America, joined Nov 2002, 16215 posts, RR: 88 Reply 2, posted (7 years 10 months 2 weeks 3 days 21 hours ago) and read 2361 times:
Not to mention the whole fleet of 747s at that time.
NW and Pratt go way back, NW was the reason why the DC10-40 was offered with the Pratts as well.
N1120A From United States of America, joined Dec 2003, 25852 posts, RR: 79 Reply 3, posted (7 years 10 months 2 weeks 3 days 21 hours ago) and read 2358 times:
Quoting PSU.DTW.SCE (Reply 1): NW initially went with the PW engines on the 752 fleet since they had PW engines on the DC-10-40's at the time and were a happy PW customer.
I am well aware of NW's allegience to PW (except on the A32S) being as strong as United's
Quoting PSU.DTW.SCE (Reply 1): and is the only operator of this type (I believe).
Yes they are
Quoting PSU.DTW.SCE (Reply 1): The reasoning behind this, as at the time, the 753 was only offered with the RR engines, thus NW was the launch customer for the PW 753's,
Actually, it was always offered with PW2000 power. It just happens there is something on the line of a 3% difference in SFC between them, which is an absolute disaster. PW pays NW for the difference. The reason I asked about the 752 is because there is also a wide gap (though not as wide) there and PW did give UA a sweetheart deal on their PW2040 powered ETOPS birds after losing DL's patronage.
Mangeons les French fries, mais surtout pratiquons avec fierte le French kiss
Mlsrar From United States of America, joined Mar 2000, 1417 posts, RR: 9 Reply 4, posted (7 years 10 months 2 weeks 3 days 21 hours ago) and read 2351 times:
Quoting Gigneil (Reply 2): NW was the reason why the DC10-40 was offered with the Pratts as well
JL was influential as well in the production of the -40, being a large PW customer as well.
NW was also the force behind enumerating what was to become the DC-10-20 into the DC-10-40.
I mean, for the right price I’ll fight a lion. - Mike Tyson
Lightsaber From United States of America, joined Jan 2005, 10696 posts, RR: 100 Reply 5, posted (7 years 10 months 2 weeks 3 days 21 hours ago) and read 2335 times:
????
The pw2038 has 7% lower fuel burn than the RB211 on the B752! Pratt isn't paying for fuel burn now. The engineers on this engine are damn proud of the fuel burn. But... Initially the Pw2038 missed its TSFC target by ~4% (oops...). As is normal in engine contracts, Pratt had to pay for a 3% fuel miss (4% minus a 1% contract "fudge factor.") Also, until the late 1990's, the pw4038 wasn't meeting maintenance goals, so Pratt was having to pay NW back for extra shop time. In fact, for a while the pw2038 was a shop queen. In effect, Pratt forfitted its Profit on the NW PW2038's for quite a bit due to excess shop time.
NW and UA tend to be happy Pratt customers as Pratt and them have a very good working relationship. (Not perfect, but good.)
As to the pw4042 (the B753 engine), Pratt hasn't been paying out much warantee.
Tornado82 From , joined Dec 1969, posts, RR: Reply 6, posted (7 years 10 months 2 weeks 3 days 16 hours ago) and read 2197 times:
Quoting Lightsaber (Reply 5): The pw2038 has 7% lower fuel burn than the RB211 on the B752
7% difference between 2 engines on the same bird is a hell of a difference!!! Engine commonality amongst fleets is one thing, but with a 7% burn difference its surprising anybody could pass up the PW's if that's the case.
United_fan From United States of America, joined Nov 2000, 7162 posts, RR: 8 Reply 8, posted (7 years 10 months 2 weeks 3 days 14 hours ago) and read 2085 times:
Wasn't it a former NW executive who once said "If I want a lightbulb,I'll buy a GE,if I want a jet engine I'll buy a Pratt & Whitney"
'Empathy was yesterday...Today, you're wasting my Mother-F'ing time' - Heat.
Lightsaber From United States of America, joined Jan 2005, 10696 posts, RR: 100 Reply 9, posted (7 years 10 months 2 weeks 3 days 12 hours ago) and read 1983 times:
Quoting Tornado82 (Reply 6):
7% difference between 2 engines on the same bird is a hell of a difference!!! Engine commonality amongst fleets is one thing, but with a 7% burn difference its surprising anybody could pass up the PW's if that's the case.
Unless the Pratt is a shop queen. And note I pointed out it was only a 3% difference at entry into service (when many airlines commited to an engine) and since then RR might have improved the fuel burn (post 2001). At $20 to $25/bbl for oil, the RR was cheaper even with this great of a fuel burn difference. (Recall, a missed flight is DAMN expensive and the pw2037 missed a few!) The RB211 is using a core designed for 58k of thrust lopping along at ~38k. So its quite a bit heavier. (Note: they did modify the high turbine quite a bit to reduce the thermo hit.) One has to consider the times the airlines committed to their purchase decision.
Note: Recall the pw2037 was the world's first in service commercial engine with mono-crystal turbine blades*. That's a 2% to 3% drop in fuel burn on its own!
Just for a tidbit on the difference in reliability circa 1998, the RB211 on the 752 was getting ~ 12,500 to 15,000 cycles between overhauls (in other words, regularly hitting the engine cycle limit). The Pratt? About 3,750. Ok, the pw2037 has improved since then, but its still only about half of the RR numbers. Recall that those overhauls are a couple of million too... Recall, 1 cycle=1 cold takeoff, but a hot/high takeoff might count for 3 or more cycles! (More is possible, but rare) Convieniently the FADAC does the math for you...
If the Pratt had been half reliable, it would have owned the 757 market. The pw2037 is the dog of the Pratt Stable and a good part of the reason airlines have gone to other engine vendors. Poor reliabilty costs. Pratt knows there is no longer any acceptible excuse for poor reliability. Will they be given a chance again? I'm hearing from people in the know there will be one last chance, possibly announced later this year. Note I said possibly.
Quoting ConcordeBoy (Reply 7): Something I'm not aware of (a possibility) or do you mean PW2037?
Umm... its the upthrust... I don't know why I always give this engine an extra 1k of thrust... oops. pw2037 is correct (Hey, in my own defense its an engine I haven't worked on. ok? If I screwed up on the pw6022/6024, pw4062, 4168 (wanna be 4172), 4090, 4098, 8163, 8157, 8133, V2500 A7, A9, or A12 I would have no excusse. Whew! Yes, most of those are paper engines/changes and I'm still under NDA for the sonic cruiser. naa naa)
Quoting United_fan (Reply 8): "If I want a lightbulb,I'll buy a GE,if I want a jet engine I'll buy a Pratt & Whitney"
Love the quote!
Lightsaber
*yea, a few caviats there on the single crystal bit...
N1120A From United States of America, joined Dec 2003, 25852 posts, RR: 79 Reply 10, posted (7 years 10 months 2 weeks 2 days 16 hours ago) and read 1810 times:
Quoting Lightsaber (Reply 5): The pw2038 has 7% lower fuel burn than the RB211 on the B752!
How can you explain the fact that all of the longest ranged 752s are RB211 powered then?
Mangeons les French fries, mais surtout pratiquons avec fierte le French kiss
N1120A From United States of America, joined Dec 2003, 25852 posts, RR: 79 Reply 12, posted (7 years 10 months 2 weeks 2 days 16 hours ago) and read 1801 times:
Quoting GQfluffy (Reply 11): I've never seen a RR-powerd 757 in DL colors. Are you refering to the GE 767s and RR 777's?
I am refering to the fact that they switched from PW4000 power to CF6 power on the 767s after taking delivery of several PW4000 powered birds because of the way PW dealt with them.
Mangeons les French fries, mais surtout pratiquons avec fierte le French kiss
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From United States of America, joined Dec 2003, 25852 posts, 
In effect, Pratt forfitted its Profit on the NW PW2038's for quite a bit due to excess shop time.
And note I pointed out it was only a 3% difference at entry into service (when many airlines commited to an engine) and since then RR might have improved the fuel burn (post 2001). At $20 to $25/bbl for oil, the RR was cheaper even with this great of a fuel burn difference. (Recall, a missed flight is DAMN expensive and the pw2037 missed a few!) The RB211 is using a core designed for 58k of thrust lopping along at ~38k. So its quite a bit heavier. (Note: they did modify the high turbine quite a bit to reduce the thermo hit.) One has to consider the times the airlines committed to their purchase decision.
Ok, the pw2037 has improved since then, but its still only about half of the RR numbers. Recall that those overhauls are a couple of million too... 
Recall, 1 cycle=1 cold takeoff, but a hot/high takeoff might count for 3 or more cycles! (More is possible, but rare) Convieniently the FADAC does the math for you...
Note I said possibly.
I don't know why I always give this engine an extra 1k of thrust... oops. pw2037 is correct (Hey, in my own defense its an engine I haven't worked on. ok? If I screwed up on the pw6022/6024, pw4062, 4168 (wanna be 4172), 4090, 4098, 8163, 8157, 8133, V2500 A7, A9, or A12 I would have no excusse. Whew! Yes, most of those are paper engines/changes and I'm still under NDA for the sonic cruiser. naa naa) 
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