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Boeing 777LR Engines!  
User currently offlineSlovacek747 From , joined Dec 1969, posts, RR:
Posted (6 years 4 months 4 weeks 4 hours ago) and read 10086 times:

Hey everyone,

I'm sure this has been discussed before but I am unsure of the answer.. Why does the 777LR not incorporate the GE115B as an option along with the GE110B? It seems that if airlines could use the 115, they could theoretically achieve more range with greater payload compared to the 110. I may be missing something here, but it just seems to me a relatively easy way to increase range and payload for the airlines who want to fly the plane even further. Thanks for the responses.

Slovacek747

43 replies: All unread, showing first 25:
 
User currently offlineCHRISBA777ER From UK - England, joined Mar 2001, 5964 posts, RR: 62
Reply 1, posted (6 years 4 months 4 weeks 4 hours ago) and read 10069 times:



Quoting Slovacek747 (Thread starter):
Hey everyone,

I'm sure this has been discussed before but I am unsure of the answer.. Why does the 777LR not incorporate the GE115B as an option along with the GE110B? It seems that if airlines could use the 115, they could theoretically achieve more range with greater payload compared to the 110. I may be missing something here, but it just seems to me a relatively easy way to increase range and payload for the airlines who want to fly the plane even further. Thanks for the responses.

I think they do - I believe EK's 77Ls are so fitted.



What do you mean you dont have any bourbon? Do you know how far it is to Houston? What kind of airline is this???
User currently offlineKrisYYZ From Canada, joined Nov 2004, 1593 posts, RR: 0
Reply 2, posted (6 years 4 months 4 weeks 4 hours ago) and read 10069 times:

The -115B is an option on the B77Ls. AFAIK, AC has GE-90-115B engines on it's B77Ws and B77Ls.

KrisYYZ

Quote:
The GE90-115B is certified at an unprecedented 115,000 pounds (512 kN) thrust and serves as the powerplant for Boeing's 777-300ER, 777-200LR, and the upcoming 777 freighter targeted for entry into service in 2008. A total of 135 777-300ERs and nine 777-200LRs have been ordered by airlines worldwide.

http://www.geae.com/aboutgeae/presscenter/genx/genx_20051109.html

Editted for Link.



[Edited 2008-03-27 06:55:56]

User currently offlineSlovacek747 From , joined Dec 1969, posts, RR:
Reply 3, posted (6 years 4 months 4 weeks 4 hours ago) and read 10071 times:

Interesting... thanks for the replys people.. So then how much extra range/payload does AC get out of the LR having the 115's vs. if it had the 110's?

Does Boeing have any data to show what one can expect to gain by using the 115 vs. 110?


Slovacek747


User currently onlineStitch From United States of America, joined Jul 2005, 30870 posts, RR: 86
Reply 4, posted (6 years 4 months 4 weeks 4 hours ago) and read 9990 times:
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Quoting Slovacek747 (Reply 3):
So then how much extra range/payload does AC get out of the LR having the 115's vs. if it had the 110's?

The MTOW is the same whether the -110B or the -115B engines are fitted. However, field performance improves with the -115B engines.


User currently offlineCruiser From Canada, joined Apr 2005, 1001 posts, RR: 7
Reply 5, posted (6 years 4 months 4 weeks 3 hours ago) and read 9941 times:



Quoting Stitch (Reply 4):

The MTOW is the same whether the -110B or the -115B engines are fitted. However, field performance improves with the -115B engines.

Its the same engine - just different software.



Leahy on Per Seat Costs: "Have you seen the B-2 fly-by at almost US$1bn a copy? It has only 2 seats!"
User currently offlineIkramerica From United States of America, joined May 2005, 21502 posts, RR: 60
Reply 6, posted (6 years 4 months 4 weeks 3 hours ago) and read 9906 times:



Quoting Cruiser (Reply 5):
Its the same engine - just different software.

So? It still allows for 5k more thrust per engine, which means it can take off in hotter weather or from shorter runways with MTOW.



Of all the things to worry about... the Wookie has no pants.
User currently offlineSlovacek747 From , joined Dec 1969, posts, RR:
Reply 7, posted (6 years 4 months 4 weeks 3 hours ago) and read 9860 times:

Great information people. Thanks for enlightening me on this issue.

Anyone have any basic numbers as to how much less runway can be expected to use by upgrading engines to 115s? I know this won't be an exact answer because of all the variable, but some rough numbers will do.

Thanks,
Slovacek747


User currently offlineWestWing From United States of America, joined Feb 2005, 2134 posts, RR: 7
Reply 8, posted (6 years 4 months 4 weeks 2 hours ago) and read 9612 times:



Quoting Slovacek747 (Reply 7):
Anyone have any basic numbers as to how much less runway can be expected to use by upgrading engines to 115s? I know this won't be an exact answer because of all the variable, but some rough numbers will do.

Please take a look at: GE90-115 On Standard 773/772ER (by Kaitak Jan 18 2007 in Tech Ops).

In the thread, Zeke discusses why a greater thrust may increase runway length because of the need to compensate for asymmetric thrust yaw on engine failure.



The best time to plant a tree is 40 years ago. The second best time is today.
User currently onlineStitch From United States of America, joined Jul 2005, 30870 posts, RR: 86
Reply 9, posted (6 years 4 months 3 weeks 6 days 21 hours ago) and read 9132 times:
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Quoting Slovacek747 (Reply 7):
Anyone have any basic numbers as to how much less runway can be expected to use by upgrading engines to 115s?

Boeing's Airport Planning Guide for the 77L/77W has the runway charts for the 77L with both the -110B and -115B engine so I'd take a look through them.

You can find them at http://www.boeing.com/commercial/airports/777.htm


User currently offlineTdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 10, posted (6 years 4 months 3 weeks 6 days 17 hours ago) and read 8819 times:



Quoting Slovacek747 (Thread starter):
Why does the 777LR not incorporate the GE115B as an option along with the GE110B? It seems that if airlines could use the 115, they could theoretically achieve more range with greater payload compared to the 110.

No more range unless you're runway length limited (which I suspect is relatively rare for a 777). The payload-range charts are the same for the two engines.

Quoting Slovacek747 (Reply 3):
Does Boeing have any data to show what one can expect to gain by using the 115 vs. 110?

For payload/range, nothing published. If you were in the odd situation of being runway length limited, you could get that from the flight computer if you had access to one. Acceleration and distance are linear in thrust so, ballpark, a 5% increase in thrust would cut your takeoff distance by about 5%.

Quoting Slovacek747 (Reply 7):
Anyone have any basic numbers as to how much less runway can be expected to use by upgrading engines to 115s?

Standard day sea level takeoff at MTOW with GE90-110B's is about 11100 ft. With GE90-115B's it's basically the same, according to the charts from Boeing that Stitch referenced above.

Tom.


User currently offlineViscount724 From Switzerland, joined Oct 2006, 25117 posts, RR: 22
Reply 11, posted (6 years 4 months 3 weeks 6 days 16 hours ago) and read 8678 times:



Quoting KrisYYZ (Reply 2):
AFAIK, AC has GE-90-115B engines on it's B77Ws and B77Ls.

Unless it's wrong, AC's website indicates that their 77Ls have the GE90-110B1 engine.
http://www.aircanada.com/en/about/fleet/77L.html


User currently offlineKrisYYZ From Canada, joined Nov 2004, 1593 posts, RR: 0
Reply 12, posted (6 years 4 months 3 weeks 6 days 16 hours ago) and read 8620 times:



Quoting Viscount724 (Reply 11):
Unless it's wrong, AC's website indicates that their 77Ls have the GE90-110B1 engine.

I've been told by very reliable sources that all of AC's B777s are -115B equipped. It has been suggested on this site before that AC copied and pasted the B777 specs from the Boeing website on to their fleet website.

KrisYYZ


User currently offlineIkramerica From United States of America, joined May 2005, 21502 posts, RR: 60
Reply 13, posted (6 years 4 months 3 weeks 6 days 16 hours ago) and read 8596 times:



Quoting WestWing (Reply 8):
In the thread, Zeke discusses why a greater thrust may increase runway length because of the need to compensate for asymmetric thrust yaw on engine failure.

I'm sorry, but this person says a lot of things, and when it comes to Boeing, it's all negative.

If there was no value in the -115 on the 77L, it wouldn't be offered. The value is shorter runways or higher temp operations.



Of all the things to worry about... the Wookie has no pants.
User currently offlineCruiser From Canada, joined Apr 2005, 1001 posts, RR: 7
Reply 14, posted (6 years 4 months 3 weeks 6 days 16 hours ago) and read 8580 times:



Quoting Viscount724 (Reply 11):
Unless it's wrong, AC's website indicates that their 77Ls have the GE90-110B1 engine.
http://www.aircanada.com/en/about/fl....html

115's:
http://www.geae.com/aboutgeae/presscenter/genx/genx_20051109.html

Quote:
GE90-115B engines will power 18 firm Boeing extended-range 777 aircraft with the purchase rights for an additional 18 777 aircraft. The 777 aircraft fleet will be a mix of 777-300ERs, 777-200LRs and the 777 Freighter. The list price value of the GE90 engines for the firm order of 777 aircraft is more than $900 million. Deliveries are scheduled to begin in 2007. The cost of engines is included in the manufacturer's list price of aircraft.

I was also trying to find the agreement between Boeing and AC to see what it had listed (only if that section wasn't blocked out).



Leahy on Per Seat Costs: "Have you seen the B-2 fly-by at almost US$1bn a copy? It has only 2 seats!"
User currently offlineXT6Wagon From United States of America, joined Feb 2007, 3393 posts, RR: 4
Reply 15, posted (6 years 4 months 3 weeks 6 days 16 hours ago) and read 8418 times:



Quoting WestWing (Reply 8):
In the thread, Zeke discusses why a greater thrust may increase runway length because of the need to compensate for asymmetric thrust yaw on engine failure.

Yes, clearly this is the case.....

run that past the 5th grader common sense test for a moment will you.

Just because it has a higher max thrust doesn't mean you HAVE to use it. Most highschool students could write the code for "solving" the issue if it even exists. Lets say you have this magic Yaw issue. With one engine out the good engine reverts to 110 mapping and you are done. You STILL get the benifit of greater acceleration of the higher thrust engines.


User currently offlineWorldTraveler From , joined Dec 1969, posts, RR:
Reply 16, posted (6 years 4 months 3 weeks 6 days 16 hours ago) and read 8384 times:

sources tell me that DL's 777LRs are 110 equipped and they are operating BOM to JFK with full passenger loads and cargo even though BOM currently has only about 9000 feet of runway available for use, apparently due to construction. I'm not sure there is anything more you could want from an aircraft of that size but to be abe to fly an 8000 mile segment with full passengers and cargo from a 9000 foot runway from a city that can have hot termperatures even in the middle of the night.

The charts on Boeing's website confirm that the LR provides considerably more capability than any other aircraft that has ever flown.


User currently offlineIkramerica From United States of America, joined May 2005, 21502 posts, RR: 60
Reply 17, posted (6 years 4 months 3 weeks 6 days 16 hours ago) and read 8304 times:



Quoting XT6Wagon (Reply 15):
run that past the 5th grader common sense test for a moment will you.

To be fair, he was also talking about putting a much more powerful engine on a base aircraft. The -110 vs. -115 is only a 4.5% of a difference, and if 4.5% is enough to throw a plane so off kilter it crashes, it's not a well designed plane.



Of all the things to worry about... the Wookie has no pants.
User currently offlineGolfOscarDelta From India, joined Feb 2008, 169 posts, RR: 0
Reply 18, posted (6 years 4 months 3 weeks 6 days 15 hours ago) and read 7410 times:

Ok guys i have a silly question.

Quoting Cruiser (Reply 5):
Its the same engine - just different software.

Does this mean that it is possible to switch between a 110B and a 115B at the toggle of a switch (or from a menu in the software)?

I'm not asking if this is currently done, but if it is possible?
and so if an airline flying the -110 wants to "upgrade/switch" to a -115 can they just load new software, or flip the switch?


User currently onlineStitch From United States of America, joined Jul 2005, 30870 posts, RR: 86
Reply 19, posted (6 years 4 months 3 weeks 6 days 14 hours ago) and read 7035 times:
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Quoting GolfOscarDelta (Reply 18):
Does this mean that it is possible to switch between a 110B and a 115B at the toggle of a switch (or from a menu in the software)?

Yes, you can purchase a plug(?) from GE that will turn a -110B into a -115B.


User currently offlineSuseJ772 From United States of America, joined Aug 2005, 815 posts, RR: 1
Reply 20, posted (6 years 4 months 3 weeks 6 days 14 hours ago) and read 6817 times:



Quoting Stitch (Reply 19):

Yes, you can purchase a plug(?) from GE that will turn a -110B into a -115B.

Why wouldn't an airline do this then? Not saying I doubt you. I am seriously asking the question why more airlines don't do this.



Currently at PIE, requesting FWA >> >>
User currently offlineXT6Wagon From United States of America, joined Feb 2007, 3393 posts, RR: 4
Reply 21, posted (6 years 4 months 3 weeks 6 days 13 hours ago) and read 6594 times:



Quoting SuseJ772 (Reply 20):
Why wouldn't an airline do this then? Not saying I doubt you. I am seriously asking the question why more airlines don't do this.

If you do not need the extra peak power, then the lower rating gets your benefits like less cost per hour.

Jet engines get the snot kicked out of them running at the edge of their peak power. So if you can take off with less power than max, you will reduce your running costs. I'm not sure exactly how they regulate the inspection/overhaul/replacement schedule, but its certain that they can make the same engine hardware wise have two different intervals for these MX visits for different max thrust plugs.

The issue is that for some fleets the 115 is already on a large fleet of 300ER so might as well maintain 100% commonality on your LR even if its just paperwork and schedules that are different. The other place is where the engine drops off on the real output due to high temps, high altitude, etc. Leaving a sea level airport in the middle of a nice cold winter is far different than taking off of an airport in a high altitude desert in the middle of summer.


User currently offlineBaron95 From United States of America, joined May 2006, 1335 posts, RR: 8
Reply 22, posted (6 years 4 months 3 weeks 6 days 13 hours ago) and read 6541 times:



Quoting Ikramerica (Reply 13):
I'm sorry, but this person says a lot of things, and when it comes to Boeing, it's all negative.

If there was no value in the -115 on the 77L, it wouldn't be offered. The value is shorter runways or higher temp operations.

I agree with the comments regarding Zeke and Boeing, however, he is correct that, in some instances, higher take-off thrust causes an increase in required runway length, because it increases Vmc to the point that it becomes the dominant factor in calculating V1 and therefore the limitant factor.

Specifically in the 77L, with its shorter body and therefore shorter distance between CG and rudder (compared to 77W), and extra 5Klbs/side could indeed place the 77L in that corner of the performance limitation more often, to the point that there is no siginificant runway/payload performance improvement. However, the way to fix this, is to offer the -115 as an option and publish take-off performance with -110 operating limits.

As per your question Ikra, there are bennefits to having -115 engines on the 77L SPECIALLY for oerators like EK, AC that operate or plan to operate 77Ls and 77Ws. The biggest bennefit is that you can have a single set of spares, rotate engines between planes, etc.

It is unclear to me if Boeing innitially offered the -115 option on the 77L or if that was an option that was added later. I think the latter is the case, and, if so, was most likely driven by operators of 77L and 77W wanting a single engine, not performance reasons.



Killer Fleet: E190, 737-900ER, 777-300ER
User currently offlineBaron95 From United States of America, joined May 2006, 1335 posts, RR: 8
Reply 23, posted (6 years 4 months 3 weeks 6 days 13 hours ago) and read 6508 times:

Sorry, I forgot to add that it is possible, it is even likely, that Boeing did not certify or provided performance numbers for the 77L actually using the 115Klbs for take-off on the 77L. They may have allowed the use of the -115 engine, but limitted it to the same parameters of the -110. Can anyone with access to the TC, Flight Manual or Flight computer verify that?


Killer Fleet: E190, 737-900ER, 777-300ER
User currently offlineTdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 24, posted (6 years 4 months 3 weeks 6 days 13 hours ago) and read 6317 times:



Quoting GolfOscarDelta (Reply 18):
Does this mean that it is possible to switch between a 110B and a 115B at the toggle of a switch (or from a menu in the software)?

Yes.

Quoting SuseJ772 (Reply 20):
Why wouldn't an airline do this then? Not saying I doubt you. I am seriously asking the question why more airlines don't do this.

Primarily money. A 115B costs more than a 110B to purchase. The upgrade plug costs about the same as the difference in purchase price between the engines. If you're on a power-by-the-hour contract with GE, you pay more for an hour on the 115B than on the 110B. If you own your own engine, you'll pay more for maintenance on the 115B than the 110B.

Quoting Baron95 (Reply 23):
Sorry, I forgot to add that it is possible, it is even likely, that Boeing did not certify or provided performance numbers for the 77L actually using the 115Klbs for take-off on the 77L. They may have allowed the use of the -115 engine, but limitted it to the same parameters of the -110.

If they did not certify the 77L with the 115B then it can't have the 115B. The fact that it can have it means that Boeing did certify it. If they took a 115B and limited it to the 110B parameter, that would be a 110B...physically, they're identical engines (not counting the programming plug).

Tom.


25 Post contains links PIA777 : Nice Video I found on Youtube: http://www.youtube.com/watch?v=5xlObdXF8VE&feature=related PIA777
26 KennyK : I wonder if the 115B will ever get a bigger brother?
27 JetMech : To be fair, you say a lot of things about Airbus, which are always negative. There are far more A'netters in your camp than the other camp. Zeke is m
28 AV757 : [quote]To be fair, you say a lot of things about Airbus, which are always negative. There are far more A'netters in your camp than the other camp. Zek
29 F14D4ever : Strictly speaking, and Tdscanuck's answer notwithstanding, one cannot change from the -110 rating to the -115 rating with the flip of a switch or cli
30 RJ111 : The -115 will probably burns a touch more in cruise than the -110. I also believe the 772LR is fuel tank limited, so you wouldn't be able to add any
31 XT6Wagon : ITS THE SAME ENGINE WITH DIFFERENT PROGRAMING why would you burn more fuel in cruise if its mechanically the same engine and its attached to the same
32 RJ111 : Calm down sweetheart. I was not aware of that.
33 Baroque : Ask Lightsaber if this is the case. If it is, he sure as heck will know why!!
34 Stitch : Both the 77L and 77W have identical base fuel tank capacities of 181,264 liters. The 77L's tank capacity can be raised to 202,270 liters with the add
35 WestWing : Can you (or anyone else) tell us approximately how much does a -115B cost compared to a -110B at initial purchase. And if the operator is paying-by-t
36 OldAeroGuy : The -115B was not initially offered on the -200LR. Offering it as an option was the result of flight testing and customer requests for more thrust un
37 Aircellist : I believe he did not even take the trouble to read Zeke's comment in the other thread. Else, he would never have written that. In short, and if I und
38 JoeCanuck : The caveat was; The important things to note are, "sometimes", and "short runway". More power doesn't mean longer take off length; it can mean longer
39 Aircellist : Your phrasing is much better than mine, but this is exactly what I intended to say. (English is my second language; I think my English is good enough
40 Post contains images JetMech : Perhaps he did read Zeke's comments, but nonetheless, still chose to take then as an anti-American criticism of Boeing   Nice breakdown of the inter
41 Tdscanuck : Unfortunately, I haven't the foggiest idea what the numbers are, although I'd love to know. Nonsense. Everyone knows that Airbus pays god under the t
42 Post contains images JetMech : For some reason, I detect a hint of jest in your post ! Regards, JetMech
43 Post contains images Tdscanuck : Never! Were I to jest, I would include the appropriate emoticon... Tom.
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