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Why 777-300ER has GE engines?But 200 and 300 have RR?

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Why 777-300ER has GE engines?But 200 and 300 have RR?

Old 28th Aug 2013, 14:55
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Why 777-300ER has GE engines?But 200 and 300 have RR?

Hi fellow professional aviators, may I ask why 300ER has GE90-115B to power it but 200 and 300 have RR? Airlines would have higher maintenance cost for it....

It takes me so long to think about it.

Thanks.
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Old 28th Aug 2013, 15:05
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copied out from a.net, you could also check wikipedia for the engine options.

777-200-------------------------------------------------------------------

GE90-77B: 77,000 BET
RR Trent 875: 73,400 BET
RR Trent 877: 76,000 BET
PW4074: 74,400 BET
PW4077: 77,000 BET

777-200ER-----------------------------------------------------------------

GE90-85B: 84,700 BET
GE90-90B: 90,000 BET
GE90-94B: 93,700 BET
RR Trent 884: 83,600 BET
RR Trent 892: 90,000 BET
RR Trent 895: 93,400 BET
PW4084: 84,400 BET
PW4090: 90,000 BET

777-200LR-----------------------------------------------------------------

GE90-110B1: 110,100 BET

777-300-------------------------------------------------------------------

GE90-94B: 93,700 BET
RR Trent 884: 83,600 BET
RR Trent 892: 90,000 BET
RR Trent 895: 93,400 BET
PW4090: 90,000 BET
PW4098: 97,900 BET

777-300ER-----------------------------------------------------------------

GE90-115B: 115,300 BET
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Old 28th Aug 2013, 15:16
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And to illuminate further on Black Swans point- the 300ER and 200 F and LR have GE-90s because no other production engine produces that amount of thrust.
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Old 28th Aug 2013, 17:18
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The baseline 777-200 was certified with all three engine types - PW4000/112", GE90, and RR Trent 800. When Boeing went to the 777-300 and -200ER, the engines were basically unchanged, just operated to higher ratings than the original.

During development of the 777-300ER/200LR, Boeing decided that the market was too small for all three manufactures to develop a 115k thrust class engine, and chose GE's proposal as sole source to upgrade the GE90. So the only engine available for the very high gross weight 777-300ER/200LR is the GE90-115B.

Note that the GE90-115B is quite a bit different than the GE90-94B series on other 777s - basically the -115B has an all new LP section as well as changes to the HP.
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Old 28th Aug 2013, 17:50
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All three manufacturers were quite reluctant to develop an engine with the thrust Boeing (mainly pressured by EK and SQ) requested.

Only GE came up with some kind of plan, but was still reluctant to go ahead and take up the cost for such a development.

Finally Boeing participated but the got exclusivity to this new engine in exchange.

The GE90 proved to be a huge success, contrary to many bad mouthes, and Airbus is since jealously waiting for a similarly powerful engine.
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Old 28th Aug 2013, 21:01
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Careful...

And to illuminate further on Black Swans point- the 300ER and 200 F and LR have GE-90s because no other production engine produces that amount of thrust.

Only because....

Trent 8104.
In 1998 Boeing proposed new longer range variants of the 777X. Taking advantage of the Trent 800's growth capability, Rolls-Royce designed and built an improved engine designated Trent 8104, which was later scaled upwards to the even larger 8115. This development was the first engine to break through 100,000 lbf (440 kN) thrust and subsequently the first to reach 110,000 lbf (490 kN). However, GE Aviation former president James McNerney (now Boeing CEO) successfully offered the aircraft manufacturer up to $500 million in money to develop the 777X in exchange for exclusivity in powering the family. Boeing agreed in July 1999 to such a deal with the GE90-110B and GE90-115B to be the sole engines on the long-range 777s.[15] This resulted in the 8104 becoming just a demonstrator programme, despite setting further industry firsts for thrust levels achieved and the first to demonstrate the use of a fully swept wide chord fan.
From an informed source.

Ok, its wiki but it is a story that this side of the pond at least, is very well known.

Last edited by TURIN; 28th Aug 2013 at 21:03.
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Old 29th Aug 2013, 02:07
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GE was simply repeating a transaction that they had made for the 737-300.
They paid Boeing about $250 million with the proviso that Boeing would have to pay it back if that model was offered with another engine. So the entry fee for RR and Pratt to participate in the very successful 737 family growth became prohibitive.
Given the cut throat competition in the civil engine market, GE's decision to pay up front for exclusivity has proven to be a brilliant business strategy. They don't need to do 'strategic' (aka loss leader) deals in those markets anymore.
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Old 29th Aug 2013, 18:53
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Why does it take you so long to think about it? I'm sure airlines appreciate your concern for their financial well-being via lower maintenance costs, but I wouldn't worry about it, if I were you. Better to keep your own financial house in order, and let the airlines worry about theirs, they got people they pay to deal with that sort of thing.
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Old 29th Aug 2013, 19:19
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flyboy, that has to be the most useless post on PPRuNe ever and I should know I've written a few.

Including this one.
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Old 29th Aug 2013, 19:30
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Just trying to inject some levity into a fairly pointless conversation. It's not like anyone is ever going to ask us, mere peons, what engines should be used and what ones should not be.
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Old 29th Aug 2013, 22:43
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Tis a fine engine is the '90-115 but it needs the extra thrust because its over a tonne heavier than the base motor
(a fine engine indeed when they fix the gearbox issues and the HPT shrouds....again!!!)
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Old 30th Aug 2013, 00:58
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I believe that the earlier answer given is correct in that....by keeping the 777-300ER as a GE-90 only aircraft, it is preventing Airbus from being able to use that engine on one of their aircraft.
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Old 30th Aug 2013, 07:06
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I believe that the earlier answer given is correct in that....by keeping the 777-300ER as a GE-90 only aircraft, it is preventing Airbus from being able to use that engine on one of their aircraft.
Which earlier answer said that ?
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Old 31st Aug 2013, 02:51
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Post #5 in different words...
"Finally Boeing participated but the got exclusivity to this new engine in exchange.

The GE90 proved to be a huge success, contrary to many bad mouthes, and Airbus is since jealously waiting for a similarly powerful engine."
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Old 31st Aug 2013, 04:11
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I was working the 777 at the time the 777-300ER/GE90-115B was launched. I don't think anyone at that time ever thought the program would enjoy anywhere near the success it has achieved.

Boeing was looking at what was called a "thrusting APU" as an alternative to development of a new 115k thrust class engine - something that would automatically kick in if an engine failed during takeoff. At the time I joked that all we really needed was a JT8D as an APU . I found out later that wasn't too far off what was really being proposed

At that time, while Pratt, GE, and RR had similar market share on the 777, the Trent was emerging as the dominant engine. While all three engines were 'new', the PW4000/112" was a relatively small upgrade of the PW4000/94" on the 747-400/767 and PW4000/100" on the A330. Although the Trent 800 shared architecture with the RB211, it was largely a new engine, and the GE90 was a totally new, pushing the state of the art, engine.

The result was, while the PW4000 had an early reliability advantage, it paid a price for it's relative lack of new technology compared to the others, and GE's paid a big reliability price for it's new technology. The Rolls Trent appeared to have found the happy middle.

That all changed with the GE90-115B. GE had been working hard on the issues that had plagued the early GE90 engines and made numerous improvements while the -115B was being developed. The end result was an engine that could produce the same amount of thrust as the Redstone rocket that launched Scott Carpenter in the USA's first manned spaceflight, with impressive fuel burn and reliability.

When launched, best case estimates were that the GE90-115B would split the 777 market with the Trent 800 (with PW4000 becoming something of a bit player). In fact, Boeing confidence in the 777-200LR was so low that, in the aftermath of 9/11, the 777-200LR was shelved for ~2 years.

What no one really foresaw was, the combination of fuel burn, reliability, and flexibility made the GE90-115B/777-300ER/200LR a world beater - basically killing the passenger version of the 747-400 in the process. The GE90 has well over 90% market share on new 777's, and Boeing is literally building 777s as fast as they can - originally designed for a max 7 airplanes/month, they're now at 8.3/month and basically sold out for the next 5 plus years.

BTW, for the 777X, although the aircraft will be larger and carry more payload the same distance, the combination of better fuel burn and lighter materials mean that the 777X engine will actually produce less takeoff thrust than the GE90-115B
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Old 31st Aug 2013, 21:32
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Boeing was looking at what was called a "thrusting APU" as an alternative to development of a new 115k thrust class engine
Perhaps a 747 classic pilot can confirm my memory:

The baseline TO performance in the Boeing AFM is "APU ON", meaning that the few Newtons worth of APU thrust is tallied in with the four real engines for TO and climb. And if APU is inop, a small TOGW penalty is taken.

Or - am I losing it?
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Old 31st Aug 2013, 22:05
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barit

On the -400, I recall it differently!

There is no thrust allowance for APU running at take off, in fact, if the APU is on for take off, there is a performance decrement due to the fact that the APU Door is open and adds drag! I think it is/was in the order of x00 kgs.

For that reason, the reduced fuel burn by not running the APU and better EGT margins, BA decided many years ago to go to packs off take offs below an arbitrary 300 tonnes TOW. Below that TOW we used a packs on take off technique.

Previously we had used 'APU to Centre Pack' take off techniques above 300 tonnes.
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Old 31st Aug 2013, 23:44
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Finally Boeing participated but the got exclusivity to this new engine in exchange.
Sounds the wrong way round to me. Boeing agreed to use only the GE engine on the 777LR (cf the CFM56 on the 737NG).

That's not the same as GE agreeing that only Boeing would be offered the engine (cf also offering the CFM56 on the A320).

Airbus is since jealously waiting for a similarly powerful engine
To power what, exactly ?
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Old 2nd Sep 2013, 02:46
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Originally Posted by barit1
Perhaps a 747 classic pilot can confirm my memory:

The baseline TO performance in the Boeing AFM is "APU ON", meaning that the few Newtons worth of APU thrust is tallied in with the four real engines for TO and climb. And if APU is inop, a small TOGW penalty is taken.

Or - am I losing it?
You sure it's not because with the APU on, the ECS bleed is not coming off the engines, thus they produce more thrust?
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Old 4th Sep 2013, 02:20
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To expand on tdracer's excellent post, at the time the 777-200X and 777-300X were being developed, all three engine manufacturers were asked for proposals for a more powerful engine.

GE had spent some USD 2.5 billion on the GE90, mostly in the belief that only RR could deliver an engine (they believed PW could not grow the PW4000 family to the necessary thrusts - PW actually delivering the PW4090 came as a rude shock), but it was trailing RR and Pratt in sales due to technical issues (fuel injector life, for example, was horrendous. Some customers had to replace at least one injector after every flight). Pratt, meanwhile, had fumbled badly with the PW4098, which missed it's fuel burn targets by 4% and the fuel-injector swirl issue on the PW4090 resulted in very high NOx levels, which impacted how much thrust could be generated (the PW4098 received the TALON 'low NOx' combustor to try and address this).

Throw in the expectation that the 777-200X and 777-300X would only see modest sales and only Rolls-Royce was willing to accept multiple engine vendors on the 777-200X and 777-300X program. GE and Pratt both demanded exclusivity, so no matter who won, the 777-200LR and 777-300ER would have had only one engine.

Of the RR customers, only CX and AA said they'd not buy a 777X powered with a GE engine and while AA held out longer than CX...

So McNerney went to GE's board and made the proposal to effectively buy their way on the 777X program as an exclusive supplier.

GE's board approved and the rest, as they say, is history.

Last edited by Kiskaloo; 4th Sep 2013 at 23:00.
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