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B752 Engine Options?

Posted: Thu Jul 30, 2020 6:42 pm
by DALMD80
I have 2 questions about the 752 and its engine options (P&W or RR). First, an aesthetic question: Which engine option do you think looks better? (IMO the RRs)
And second, a technical question: Which engine option was more efficient, and which gave better performance (regardless of efficiency)?

Re: B752 Engine Options?

Posted: Fri Jul 31, 2020 5:39 pm
by stratosphere
DALMD80 wrote:
I have 2 questions about the 752 and its engine options (P&W or RR). First, an aesthetic question: Which engine option do you think looks better? (IMO the RRs)
And second, a technical question: Which engine option was more efficient, and which gave better performance (regardless of efficiency)?


When I worked for NW we only had [email protected] 757's where I work now we operate both RR and PW . I have talked to our dispatch they say the RR has better performance. I have only turned wrenches on the PW tho I also think the PW is the better looking engine on that bird. But beauty is in the eye of the beholder I guess.

Re: B752 Engine Options?

Posted: Fri Jul 31, 2020 10:51 pm
by LH707330
Efficiency goes to the Pratt by 2-3 percent, IINM.
Performance is a bit of a vague term, but the RR had a higher max thrust version and spools faster due to the three-shaft design.

Re: B752 Engine Options?

Posted: Sat Aug 01, 2020 2:34 am
by Dalmd88
From the history side of the equation the Pratt was cheaper new. It did have a few more teething problems though. Rumor has it Rolls approached Delta after we had about ten 757 delivered and were already doing pylon mods on the Pratts. We will pay to re-engine your ten planes if you switch all new deliveries to Rolls. Delta stuck with the Pratt. Years later the Pratts had another snag that left many 757 sitting on the ATL TOC ramp with no engines installed while Pratt scrambled to provide parts.

When I worked in BOS the AA guys came over one night and said you guys always seem to have your 757 cowlings open every night. We open ours once in a while just to remember what the engine looks like. In defense of the Pratt, we did A checks most nights, they obviously didn't.

I never worked on the RB that hangs on the 757. From a mtc stand point the PW2000 was a pretty good engine to work on wing. It rarely had operational issues on a nightly basis like the old JT8. It had a better bleed system than the CFM. It didn't suffer from the shake issues that are common on the big brother PW4000. I always liked doing the engine change on PW2000 more than any other engine in our fleet.

Re: B752 Engine Options?

Posted: Sat Aug 01, 2020 3:03 am
by fr8mech
We have al;l sorts of bleed issues on our Pratts. The Rolls, not as much, though the PRSOV is a bear. The Rolls is a good engine, but we see a lot of surges. I can't remember the last time we had a Pratt surge. I guess that's the difference between a FADEC and non-FADEC engine.

DALMD80 wrote:
I have 2 questions about the 752 and its engine options (P&W or RR). First, an aesthetic question: Which engine option do you think looks better? (IMO the RRs)


I think the Pratt looks "right" on the B757. The Rolls seems a little small for the wing.

Re: B752 Engine Options?

Posted: Sat Aug 01, 2020 5:41 am
by KFTG
The CF6 would have been an option on the 757, but GE backed out.
I prefer the look of the original RR engines on the 757, simply for nostalgia.


Re: B752 Engine Options?

Posted: Sat Aug 01, 2020 3:30 pm
by MO11
Dalmd88 wrote:
From the history side of the equation the Pratt was cheaper new. It did have a few more teething problems though. Rumor has it Rolls approached Delta after we had about ten 757 delivered and were already doing pylon mods on the Pratts. We will pay to re-engine your ten planes if you switch all new deliveries to Rolls. Delta stuck with the Pratt. Years later the Pratts had another snag that left many 757 sitting on the ATL TOC ramp with no engines installed while Pratt scrambled to provide parts.

When I worked in BOS the AA guys came over one night and said you guys always seem to have your 757 cowlings open every night. We open ours once in a while just to remember what the engine looks like. In defense of the Pratt, we did A checks most nights, they obviously didn't.



What's interesting is that AA ordered PW2037 engines for its 757s in the early '80s. That order was subsequently canceled due to the economy (remember those interest rates?). When AA ordered the airplane again in 1988, it had switch to RR. I don't know if RR provided a better deal, or if AA was able to gather data from airlines that had been flying the airplane for several years.

Also interesting that UPS switched from PW2040 to RB211 after the first 35 airplanes. In fact, it ordered its last 5 PW-powered airplanes and its first 20 RR-powered airplanes on the same day.

Re: B752 Engine Options?

Posted: Sat Aug 01, 2020 6:10 pm
by 747classic
1049 produced

617 (59%) with RR

432 (41%) with PW


This topic has already been discussed in detail here : viewtopic.php?t=551949

See reply 43 for some interesting maintenance cost short haul /long haul and fuel burn figures..

Re: B752 Engine Options?

Posted: Mon Aug 03, 2020 9:12 am
by Max Q
I flew the 757 with the RB211, have not operated the P&W version


Cant praise the RR engine enough, it was the smoothest, most responsive engine I’ve ever operated and I never had the slightest problem with it


The GE engine on the 767 was excellent as well but it couldn’t compete with Rolls for smoothness, it was noticeably ‘buzzy’ in a certain thrust range



Riding as passenger on the 777 I’ve noticed the same thing, that bigger RR engine is extremely smooth with the GE competitor not as much

Re: B752 Engine Options?

Posted: Thu Aug 06, 2020 5:13 pm
by stratosphere
fr8mech wrote:
We have al;l sorts of bleed issues on our Pratts. The Rolls, not as much, though the PRSOV is a bear. The Rolls is a good engine, but we see a lot of surges. I can't remember the last time we had a Pratt surge. I guess that's the difference between a FADEC and non-FADEC engine.

DALMD80 wrote:
I have 2 questions about the 752 and its engine options (P&W or RR). First, an aesthetic question: Which engine option do you think looks better? (IMO the RRs)


I think the Pratt looks "right" on the B757. The Rolls seems a little small for the wing.


We had a lot of problems with bleed issues on the RR powered ones too

Re: B752 Engine Options?

Posted: Mon Aug 10, 2020 10:16 pm
by Calledonian
Bit of a related question here. Is it possible to swap the engines on a 757 from RR to P&W or vice versa?

Re: B752 Engine Options?

Posted: Mon Aug 10, 2020 11:42 pm
by dennypayne
Calledonian wrote:
Is it possible to swap the engines on a 757 from RR to P&W or vice versa?


Anything's possible with enough money, but all the instances of airlines selling off frames acquired in mergers that don't match their existing fleet would suggest that it's not an economical proposition.

Re: B752 Engine Options?

Posted: Tue Aug 11, 2020 10:42 am
by KFTG
Calledonian wrote:
Is it possible to swap the engines on a 757 from RR to P&W or vice versa?

Yes, but it has only been done on the prototype. LN 1 originally flew with RB211s; it was later fitted with PW2000s.

Re: B752 Engine Options?

Posted: Tue Aug 11, 2020 2:47 pm
by SRQKEF
One thing is for sure, nothing beats the spool-up sound of the RB211s!

Re: B752 Engine Options?

Posted: Wed Aug 12, 2020 6:29 am
by sho69607
The RR's fit the 757 so well. The RR's look a bit strange on the 767 though.

Re: B752 Engine Options?

Posted: Thu Aug 13, 2020 4:53 pm
by strfyr51
dennypayne wrote:
Calledonian wrote:
Is it possible to swap the engines on a 757 from RR to P&W or vice versa?


Anything's possible with enough money, but all the instances of airlines selling off frames acquired in mergers that don't match their existing fleet would suggest that it's not an economical proposition.

Only if you swap the pylons as well. It can be done, but I'm not sure why you would want to.

Re: B752 Engine Options?

Posted: Fri Aug 14, 2020 12:23 am
by fr8mech
strfyr51 wrote:
dennypayne wrote:
Calledonian wrote:
Is it possible to swap the engines on a 757 from RR to P&W or vice versa?


Anything's possible with enough money, but all the instances of airlines selling off frames acquired in mergers that don't match their existing fleet would suggest that it's not an economical proposition.

Only if you swap the pylons as well. It can be done, but I'm not sure why you would want to.


Don't forget, since the P&W engines are FADEC, while RR aren't, you'd need add the control path from the flight deck to the fuel flow governor, and delete the control wiring specific to the P&W.

Re: B752 Engine Options?

Posted: Fri Aug 14, 2020 2:32 am
by TTailedTiger
I ways preferred the look of the P&W engine. The thrust reverser on RR 747/757/777 engines just looks odd to me. The RR engine just looks too one dimensional.