sleekjet
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AA 757 Engines

Sun Jun 23, 2002 5:31 am

I'm not much at techs and specs, so....how can I tell whether the 757 I'm flying next week is equipped with RR's or PW's?
II Cor. 4:17-18
 
AFC_Ajax00
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RE: AA 757 Engines

Sun Jun 23, 2002 5:56 am

The RR engines have cylinder type nacelles instead of the PW ones that taper off into an exhaust cone at the end. Hope this helps.
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sleekjet
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RE: AA 757 Engines

Sun Jun 23, 2002 7:07 am

So, which would these be?


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II Cor. 4:17-18
 
MDL_777
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RE: AA 757 Engines

Sun Jun 23, 2002 7:11 am

The engines in the photo are Rolls Royce engines.
 
LMP737
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RE: AA 757 Engines

Sun Jun 23, 2002 1:17 pm

Here's a list of US carriers that fly the 757 and the engines they use:

American-RR
TWA LLC-PW
United-PW
Northwest-PW
Delta-PW
Continental-RR
America West-RR
ATA-RR
National-RR
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wilax
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RE: AA 757 Engines

Mon Jun 24, 2002 5:23 am

If you cannot eyeball the engines, the plane registration will tell you. If the last two letters are TW, it has the Pratt&Whitney's, but if it ends in AA or AN, you've got the double R's baby...
 
BWIrwy4
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RE: AA 757 Engines

Thu Jun 27, 2002 12:50 pm

LMP737: You forgot US Airways-RR
 
LMP737
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RE: AA 757 Engines

Thu Jun 27, 2002 2:00 pm

BWIrwy4:

You are correct. When I was typing the post I had this nagging feeling that I was forgetting an airline.
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American 767
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RE: AA 757 Engines

Sun Jun 30, 2002 8:00 pm

That's right. US Airways 757's were originally oparated by Eastern which selected the RR power plant. US and BA were the first two airlines to introduce the 757 almost 20 years ago, they both chose RR engines. Next was Delta, which was first to introduce the 757 with PW engines. More airlines choose RR engines because they generate more power than PW engines, 43000lbs vs 37000lbs of thrust. The reason Northwest and United chose PW engines is because they always had a strong relationship with that engine manufacturer. However, the advantage of the PW engine is its high-bypass ratio, which makes it a quiet engine.

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American 767
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RE: AA 757 Engines

Sun Jun 30, 2002 8:03 pm

Correction: I just realized my mistake. I said US and BA were the first airlines to introduce the 757, I meant EASTERN and BA.

Ben
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RE: AA 757 Engines

Tue Jul 02, 2002 9:00 am

American 767, the PW2000 series engines can put out more than 37,000lbs thrust, there is a version available for the new 757-300 that has 43,000lbs thrust that I believe NW has ordered. Go to the P&W website and check it out yourself.
 
flynavy
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RE: AA 757 Engines

Sat Jul 06, 2002 5:02 am

Correct me if I am wrong, but is it not true that Delta operates both PW and RR powered 757's?
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Rick767
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RE: AA 757 Engines

Sat Jul 06, 2002 6:19 am

Flynavy,

Delta only operate the PW2037 engines on their 757 fleet.
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wingscrubber
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RE: AA 757 Engines

Sun Jul 07, 2002 2:05 am

How come continental have RRs on their 757s but GEs on their 777s? Being British, I reckon the Trent is the best choice  Laugh out loud

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Delta767300ER
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RE: AA 757 Engines

Wed Apr 19, 2006 3:16 am

This is a bit off topic but a RR engine on a Boeing 757 sounds dull and like a buzzsaw. I would rather hear the P&W powerful whine. Thankfully all of Delta's Boeing 757's and P&W powered.

-Delta767300ER
 
ftrguy
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RE: AA 757 Engines

Fri Apr 21, 2006 1:28 am

You can also go to the seatmap of your flight where you picked your seat. If it starts with row 7 in Y you will have a PW powered one. If it starts with row 9, you will have a RR powered one. Go to seatguru.com and see the difference.
 
ReidYYZ
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RE: AA 757 Engines

Fri Apr 21, 2006 9:56 am

Is there any truth about AA originally getting/ordering the '57 with P&W and then converting/trading in for RR powered a/c? I heard that over 15 years ago, never found any proof.
 
UAL747
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RE: AA 757 Engines

Fri Apr 21, 2006 10:14 am

The AA 757's for the majority have RR engines. Only the TWA acquired ones have P&W. The nacelle of the engine on a RR continues all the way to the back (well, not necessarily the nacelle, but the grey and silver parts are flush on a RR). The P&W have a shape where the grey part of the nacelle ends and theres a space between the silver part (on the back).

Blah, I'm drinking, I dunno what I'm talking about. hope that helps.

UAL
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LMP737
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RE: AA 757 Engines

Fri Apr 21, 2006 10:49 am

Quoting Flynavy (Reply 11):
Correct me if I am wrong, but is it not true that Delta operates both PW and RR powered 757's?

No but I do believe that they operate GE and PW powered 767's.
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FrancoBlanco
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RE: AA 757 Engines

Fri Apr 21, 2006 7:18 pm

Interesting info, but why is a four year old thread brought up again? I am sure there have been some other threads about 757s/PW/RR in the meantime.

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aogdesk
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RE: AA 757 Engines

Fri Apr 21, 2006 11:36 pm

The RR powered birds have fewer blades per engine than the Pratts, 22 vs 37 I believe. So on takeoff roll, peer into the engine and count each individual blade as it passes top center.  Smile
 
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Starlionblue
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RE: AA 757 Engines

Sat Apr 22, 2006 1:29 am

Quoting Ftrguy (Reply 15):
You can also go to the seatmap of your flight where you picked your seat. If it starts with row 7 in Y you will have a PW powered one. If it starts with row 9, you will have a RR powered one. Go to seatguru.com and see the difference

To continue this, the TWA ones have a galley in the middle and no power ports in monkey class.
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HAWK21M
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RE: AA 757 Engines

Sun Apr 30, 2006 5:01 am


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Photo © Medolago Manuel


RR logo looks good.
RB211-535E4


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Photo © Krzysztof Skowronski [epwa_spotters]


P&W 2000

regds
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ReidYYZ
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RE: AA 757 Engines

Sun Apr 30, 2006 9:50 am

Quoting HAWK21M (Reply 22):
RR logo looks good.
RB211-535E4

That is an RB211-535C engine, the original photo caption is incorrect.
The 535E4 looks like:

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Photo © Darren Wilson


The 'RR' logo decal is indeed sweet. At $500.00US a pop, it's very rich too. I managed to get one off a cowling about to be painted and re-glued it to my box.
 
Molykote
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RE: AA 757 Engines

Sun Apr 30, 2006 1:06 pm

Quoting Delta767300ER (Reply 14):
This is a bit off topic but a RR engine on a Boeing 757 sounds dull and like a buzzsaw. I would rather hear the P&W powerful whine. Thankfully all of Delta's Boeing 757's and P&W powered.

-Delta767300ER

You may prefer the PW sound to the RR sound but rest assured it's likely to be a less powerful whine!
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HAWK21M
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RE: AA 757 Engines

Sun Apr 30, 2006 11:06 pm

Quoting ReidYYZ (Reply 23):

You are correct about the -535C & -535E4.

What did you use to reglue the RR Decal.
regds
MEL
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UAL747
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RE: AA 757 Engines

Mon May 01, 2006 6:05 am

Wow, I didn't realize there were two different RR engine variants. Can anyone give a little more information on this?

Thanks,

UAL
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LH463
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RE: AA 757 Engines

Mon May 01, 2006 6:44 am

I love the 757 engines with the RR's attached. They are the only ones that can seem to do this...

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Turning final...
 
midnights
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RE: AA 757 Engines

Mon May 01, 2006 6:48 am

It's real simple.....if there's a puddle of oil under the engine, it's a P/W... no puddle, R/R.
 
ReidYYZ
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RE: AA 757 Engines

Mon May 01, 2006 9:45 am

Quoting HAWK21M (Reply 25):
What did you use to reglue the RR Decal.

I mis-stated, actually it went on with it's original adhesive as it was unmolested.

Quoting Midnights (Reply 28):
it's a P/W... no puddle, R/R.

If it has a vibration issue, it's a RR......no vib's, P/W.
 
jetflyer
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RE: AA 757 Engines

Mon May 01, 2006 11:02 am

Quoting Delta767300ER (Reply 14):
This is a bit off topic but a RR engine on a Boeing 757 sounds dull and like a buzzsaw. I would rather hear the P&W powerful whine. Thankfully all of Delta's Boeing 757's and P&W powered.

Well having lived outside Heathrow for 12 years I think the RR 757 sounds awesome and the PW is rubbish.

And I've flown on a RB-211 powered 767 and it is over twice and quiet as the GE version with NO Buzz-saw either.

[Edited 2006-05-01 04:03:19]
 
FrancoBlanco
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RE: AA 757 Engines

Tue May 02, 2006 1:25 am

Quoting UAL747 (Reply 26):
Wow, I didn't realize there were two different RR engine variants. Can anyone give a little more information on this?

OK, I am no expert but here you are:

The first RR engine for the 752 was the RB211-535C. Somewhen around 1985, the -535E4 was introduced. It has slightly more power and the nacelle has a different design, as stated above. AFAIK all new 752s came with the E4 from that time on and some of the older built were re-engineered.

Later, in the nineties, an even more powerful version was introduced, the -535E4B. It is intended for use on the 753 and some heavier 752s. From a spotters point of view, you cannot distinguish them.

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gt1
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RE: AA 757 Engines

Tue May 02, 2006 5:15 am

Some time around 1998, I heard a Delta VP of Maintenance say that Delta considered the 757 with the RR to be the best engine/airframe combination. Of course Delta had probably around 100 PW powered 75's then.

The issue is reliability. I don't have the exact numbers, but last I heard, the average RB211-535 stays on the wing 2-3 times longer than the PW2000. Does anyone have some numbers?

Some folks think the Rolls -535 is arguably the most reliable current commercial engine, while the PW2000 is arguably the least

One good thing about the PW2000: Propulsion Engineer and AMT job security
 
Molykote
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RE: AA 757 Engines

Tue May 02, 2006 3:17 pm

Quoting Gt1 (Reply 32):
Some time around 1998, I heard a Delta VP of Maintenance say that Delta considered the 757 with the RR to be the best engine/airframe combination. Of course Delta had probably around 100 PW powered 75's then.

The issue is reliability. I don't have the exact numbers, but last I heard, the average RB211-535 stays on the wing 2-3 times longer than the PW2000. Does anyone have some numbers?

The RB211-535 has had above average reliability and exceptional longevity in my experience.

The longevity is at least in part due to the fact that this engine is pretty underworked most of the time. The associated drop in TIT pretty much pays dividends for overall engine life.

The RB211-535 reliability has also been good but not as striking as longevity.

One of the recurring maintenance headaches with these engines are the balance problems associated with the fewer and larger/heavier fan blades. The large blades promote engine imbalance and to an extent are countered with weights on the hub of the LPC. RR fan balance solutions are pursued using moment weight data in the radial, tangential, and axial directions (compared to some other engines only being concerned with radial moment weight for balance solutions). This is also due to the larger fan blades and the larger variance in mass centroid positions due to the greater physical space these blades occupy in the tangential and axial directions stemming from wide chord constructions.

In addition to the size of RR engine fan blades, the relatively low number of blades also present balance problems. Imagine trying to neutralize an old style balance scale using a number of 5 lb weights or a larger quantity of 1 oz weights. You may imagine that the smaller weight increments permit a more precise degree of balance to be achieved. With an RB211 you've got 22 large heavy fan blades that you are trying to arrange in 22 equally spaced positions around a 360-deg arc. With other engines you might have closer to 40 smaller blades arranged over equally spaced positons on a 360-deg arc. Intuitively you can probably see why the native* balance of 40 blades is likely to be superior to that of a 22 blade configuration.

Other common issues with the RB211-535 are annulus filler cracks (these are basically spacers between the fan blades) and misrigging of the AHAD door (basically a movable fairing that goes through some monkey motion to permit deployment of the T/R). In fairness, most people don't consider the T/R to be part of the powerplant. Often times they are designed by different companies.

* - By native balance I am referring to the mass/centroid/inetria distribution achieved by arranging fan blades of varying weight in slots on the fan hub. Imperfections in the native balance of an installed fan set can be further neutralized with the addition of balance weights on the fan hub.

Quoting Gt1 (Reply 32):
Some folks think the Rolls -535 is arguably the most reliable current commercial engine, while the PW2000 is arguably the least

One good thing about the PW2000: Propulsion Engineer and AMT job security

I can't speak about the PW2000. The sheer number of customers who selected the RB211 do suggest to me that it was better for the majority of service scopes but I can't speak much about the PW.

I'd personally put the CF6-80 on equal footing with the RB211-535 as far as durability and reliability.
Speedtape - The aspirin of aviation!
 
LMP737
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RE: AA 757 Engines

Tue May 02, 2006 11:05 pm

Quoting Gt1 (Reply 32):
One good thing about the PW2000: Propulsion Engineer and AMT job security

You can always tell where a 757 with PW2000 has been parked. Just look for the puddle of oil.  Wink
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Rj111
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RE: AA 757 Engines

Tue May 02, 2006 11:06 pm

I find it interesting that the RB211-524 didn't fair so well on the 767 and 747.

Can anyone list the key reasons why this is?

I'd guess that it is because it is less powerful and consumes more than the GE6-80 and PW4062, and becuase in the 767's case it was late on the scene as a BA request.

Also does anyone know the range of the 763ER with RB211s as Boeing don't put this in their detailed 767 info.
 
LMP737
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RE: AA 757 Engines

Tue May 02, 2006 11:15 pm

Quoting RJ111 (Reply 35):
I find it interesting that the RB211-524 didn't fair so well on the 767 and 747.

Can anyone list the key reasons why this is?

With the 767 the RB211 was a late on the scene. The first version, the -200, was only powered by the CF6 and PW4000. It was only with the -300 did the RB211 become avaliable. Unfortanetly for RR airlines like AA were not willing to have two different type engines powering it's 767 fleet.
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gt1
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RE: AA 757 Engines

Wed May 03, 2006 12:20 pm

Molykote, that was a very informative post on engine balance, nice job. I'm guessing you've spent some quality time with a PBS-4000 system.

You are correct in that some engines have a greater number of fan blades. If memory serves, the PW4000 (94 inch) and the CF6-80C2 both have 38 fan blades.

I also agree that the CF6-80 has a similar level of reliability, even though Delta has had some problems with the 764 engine, possible due to the high cycle flying those jets do.

Another joke/anecdote regarding the RB211-535 I remember from my younger days: 'The Eastern guys forgot how to open the cowling on their 757's.........'
 
Airmech56
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RE: AA 757 Engines

Fri May 05, 2006 9:44 pm

[quote=Wingscrubber,reply=13]How come continental have RRs on their 757s but GEs on their 777s? Being British, I reckon the Trent is the best choice


The reason CO choose the GE90 is because they are more effiecient than the RR Trent, since we fly from EWR to China/ Japan non-stop , efficiency was more important than power. Also, CO has a very deep relationship with GE. The entire fleet, besides the 757 have GE's in them.

[Edited 2006-05-05 14:45:06]
 
Molykote
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RE: AA 757 Engines

Mon May 08, 2006 5:54 pm

Quoting Gt1 (Reply 37):
Molykote, that was a very informative post on engine balance, nice job. I'm guessing you've spent some quality time with a PBS-4000 system.

You are correct in that some engines have a greater number of fan blades. If memory serves, the PW4000 (94 inch) and the CF6-80C2 both have 38 fan blades.

I also agree that the CF6-80 has a similar level of reliability, even though Delta has had some problems with the 764 engine, possible due to the high cycle flying those jets do.

Another joke/anecdote regarding the RB211-535 I remember from my younger days: 'The Eastern guys forgot how to open the cowling on their 757's.........'

Gt1:

Thanks for the compliment - I was somewhat rushed in my post but glad at least the gist of my input was understood.

It looks like we have some similar experience. I don't know much about the 764 but I was surprised at some of the short hops this a/c did in the US. (My dad recently flew a packed 764 from ATL-TPA.)

I'm sure that neither the cycle count nor thrust rating are helping on the 764.
Speedtape - The aspirin of aviation!
 
kgfive
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RE: AA 757 Engines

Tue May 09, 2006 8:57 am

Cynical bugger here....does it really matter to us " joe public " what engine is hanging from the wing as long as when you land on time or safely the engines are still there  airplane  think I need my bed  zzz 

G.E. CF6-80C2 have a good whine though  bigthumbsup 
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lightsaber
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RE: AA 757 Engines

Thu May 11, 2006 9:34 am

Quoting Molykote (Reply 33):
The longevity is at least in part due to the fact that this engine is pretty underworked most of the time. The associated drop in TIT pretty much pays dividends for overall engine life.

 checkmark  But if I may expand on the answer to this question:

Quoting Gt1 (Reply 32):
Some time around 1998, I heard a Delta VP of Maintenance say that Delta considered the 757 with the RR to be the best engine/airframe combination. Of course Delta had probably around 100 PW powered 75's then.

The issue is reliability. I don't have the exact numbers, but last I heard, the average RB211-535 stays on the wing 2-3 times longer than the PW2000. Does anyone have some numbers?

Some folks think the Rolls -535 is arguably the most reliable current commercial engine, while the PW2000 is arguably the least

One good thing about the PW2000: Propulsion Engineer and AMT job security

I know the RR is very reliable. On average, 15,000 cycles between overhauls when cycle limited. Most -535 engines go in do to hours just taking their toll (coatings wear, etc.). However, RR designed the engine for 7,500 cycles! That great reliability is coming from an understressed core (as noted) which results in poor fuel burn. RR messed up there... its costing the airlines more in fuel having than the benifit of that long engine life. Ok, a classy mistake, but not what RR intended.  spin 

Now, Pre-1998 the Pratt's were only getting 3,750 cycles on average!  wideeyed  The durability and reliability of the PW2000's was costing the airlines a fortune. Recall that this is back when an engine overhaul would take 78+ days! So having a whole fleet need 2X more overhauls than plan was a double cost hit:
1. Cost of overhaul (partially comped by gaurantee)
2. Lost use of airframes due to the shear number of engines in the shop! Spare Pw2000's became very precious... and buying more spares is not a cheap fix. Oh... customers were not happy. I doubt DL will forgive Pratt within my career.  Sad

That 3,750 cycle life is very poor. This is for an engine designed for 7,500 cycles too. There was a kit put out in 1998 (IIRC the year correctly) to fix the turbine durability issue. While I've heard good things about the kit, I do not know the current average on wing life of the Pw2000. I know on wing time is improved as well as durability from the scuttlebut... but I do not know the quantitative improvement.

Do look at the much lower fuel burn of the PW2000 vs. the RB211-535. How is this so? The PW2000 is the first commercial engine with single crystal turbine blades!  bigthumbsup  Sometimes it hurts to be first.
http://www.alair.com/Commercial/pw2000.html
http://www.alair.com/Commercial/rb535.html

The RR gets a fairly poor cruise TSFC of 0.607. Good thing the 757 is very aerodynamic! The Pratt? Cruise TSFC of 0.563. Yes, a ~7% advantage to Pratt! That's huge! But due to the poor reliability of the Pratt, it was cheaper to operate the RB211...  Sad I should note at entry into service that the Pratt missed fuel burn targets, but was quickly brought back to promise.

So think about this... the 757 was a very successfull airframe *without* a truly optimal engine. The RB211 was robust but a little bit of a gas hog (about 3% more than typical of the time). The PW2000 was a fuel mizer (about 4% better than typical of the time due to the single crytal tech) but a MX nightmare for most of the sales life of the 757.

The fact that the RB211 and the PW2000 weighed within 30 lbm of each other (~7,300lbm) shows how much weight the improved component efficiencies of a triple spool can save. Why do I say this? The -535 is a shrunk engine and thus should have been much heavier than the PW2000 (The -535 is the older design). But the -535 and PW2000 effectively weight the same!  bigthumbsup 

Look, I'm a Pratt fan... But I believe in just putting the facts on the table.

Lightsaber
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jeb94
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RE: AA 757 Engines

Tue May 16, 2006 9:24 am

In talking with a former coworker who worked at National and then TMA, he loved the Pratts because of their plug and play nature. The PW2000 is Fadec while the old RB211 is not. Keep in mind that the RB211, as good as it is, is the same engine program that practically killed the L1011 with development delays and effectively eliminated Lockheed as a commercial aircraft manufacturer.
 
aogdesk
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RE: AA 757 Engines

Tue May 16, 2006 9:37 am

Count the fan blades as they rotate  Wink

PW: 37 blades
RR: 22 blades
 
Go3Team
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RE: AA 757 Engines

Tue May 16, 2006 11:51 am

Quoting Lightsaber (Reply 41):
Recall that this is back when an engine overhaul would take 78+ days!

Wait, what? Why so long?
Yay Pudding!
 
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lightsaber
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RE: AA 757 Engines

Tue May 16, 2006 3:17 pm

Quoting Go3Team (Reply 44):

Wait, what? Why so long?

The improvement in shop practaces that occured during the last 15 years is amazing. But there are some major changes that occured that result in today's faster turns:

1. Today, an engine is worked 24/7 until the puppy is back into the fleet. I the past, union shops were most efficient 8/5.  wideeyed  40 hour work weeks eat up a lot of interest on that capital... Somewhere along the way the unions realized either they allowed 6 shifts to man a work week or their jobs were toast.
2. Automated x-ray. Doing film x-ray took forever. This took a three to six week task down to a 48 hour task.  wideeyed 
3. Part binning via database: engines can be kitted with the correct remaining life parts. Before, you pretty much had to wait until *all* of an engines parts made it back from repair to verify the rebuilt engine was going to meet target life. Now engine #313 might go out with engine #250's turbine rotor while engine #422 get's engine #313's... Engines are like legos. You care about part life and quality (not to mention pedigree), but they're interchangable parts. But this takes computerized tracking of parts to be an efficient method. Database software wasn't up to snuff at EIS of the PW2000.

4. consolodation of engine work. Instead of every airline rebuilding their own engines, having massive shops means that its now possible to have a spare set of long lead time parts on hand. This is also an artifact of fleet simplification. If a shop is rebuilding 100+ CFM-56-7's a year (V2527's or whatever your favorite mass produced engine is), they can afford to have four to six extra sets of turbine blades in the repair process while an airline that is self repairing less than a dozen of one engine type per anum cannot afford even one spare set. If you're short one part... the engine sits.

I could also go into new weld processes and such that speed up repairs.

Much of this is due to the realization that spare engines are a huge money pit and that by spending $20k or so speeding up an engine overhaul saved more on engine lease costs (or interest payments). Eventually, the fast turn became the standard sans "quick turn" premium.  spin  Most of the old spare engine fleet was parted out years ago to save on overhaul costs.

Quick summary:
1. computerization of part tracking
2. Shift optimization to move the product
3. Automation of the inspection and repair.
4. All driven by the economies of scale created by either:
a. fleet simplification (more of one type of engine)
b. outsourcing to an engine repair shop who sees enough of that engine to gain economies of scale.

And the compitition for business is so brutal I expect the engine repair shops to improve more in the next decade than they did in the last!  wideeyed 

Lightsaber
"They did not know it was impossible, so they did it!" - Mark Twain
 
Go3Team
Posts: 3156
Joined: Sun Mar 14, 2004 1:19 am

RE: AA 757 Engines

Tue May 16, 2006 9:17 pm

Quoting Lightsaber (Reply 45):

Thanks for the detailed reply.

Now that I think about it, I can see it. Imagine having to take your car in for a new engine, and having to wait 2.5 months for it. Of course the jet engine is much more sophisticated.
Yay Pudding!
 
lotsamiles
Posts: 254
Joined: Wed May 18, 2005 1:22 am

RE: AA 757 Engines

Thu May 18, 2006 3:27 am

Lightsaber,
Your knowledge on the 757 engines is impressive.

Do you happen to know about an engine mount change that was done on the PW2000 series engines to reduce vibration induced damage to the mounts? I have heard about it but not with any specifics. I understand the new design is similar to what can be found on the RR211-535E4 powered aircraft.

Thanks,
Lotsamiles
 
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lightsaber
Crew
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RE: AA 757 Engines

Fri May 19, 2006 4:20 am

Quoting Lotsamiles (Reply 47):
Do you happen to know about an engine mount change that was done on the PW2000 series engines to reduce vibration induced damage to the mounts? I have heard about it but not with any specifics. I understand the new design is similar to what can be found on the RR211-535E4 powered aircraft.

Alas, I do not know these details about the PW2000 nacelle.

Lightsaber
"They did not know it was impossible, so they did it!" - Mark Twain
 
MarkC
Posts: 238
Joined: Tue Apr 25, 2006 8:10 am

RE: AA 757 Engines

Sun May 28, 2006 11:29 am

Quoting Lotsamiles (Reply 47):
Do you happen to know about an engine mount change that was done on the PW2000 series engines to reduce vibration induced damage to the mounts? I have heard about it but not with any specifics. I understand the new design is similar to what can be found on the RR211-535E4 powered aircraft.

Thanks,
Lotsamiles

You are definately talking about an airframe change, not an engine change. As far as the engines are concerned, the forward mount P/N is the same on all models and configs. The rear mount is really just a busing in the turbine exhaust case.

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