Boeingfever777 From United States of America, joined Jul 2009, 409 posts, RR: 56 Posted (3 years 9 months 1 week 5 days 14 hours ago) and read 5863 times:
I know the GE90-115B is the strongest commercial built engine.
I want to know what is the max thrust is can produce? Someone told me it hit 127,000lbs... At that amount of thrust would not that be considered a redline and constitute a burnt up engine?
Does GE even sell engines to Boeing that have alloy that can with stand that?
I thought a 777 would only max thrust at takeoff when fully loaded?
747classic From Netherlands, joined Aug 2009, 1815 posts, RR: 11 Reply 1, posted (3 years 9 months 1 week 5 days 13 hours ago) and read 5851 times:
Quoting Boeingfever777 (Thread starter): I want to know what is the max thrust is can produce? Someone told me it hit 127,000lbs
"In late 2002, the engine shattered its original record by reaching 127,900 lbs. of thrust during required certification testing", see following link : http://www.geae.com/engines/commercial/ge90/
Jetlagged From United Kingdom, joined Jan 2005, 2462 posts, RR: 17 Reply 2, posted (3 years 9 months 1 week 5 days 13 hours ago) and read 5835 times:
Quoting Boeingfever777 (Thread starter): I want to know what is the max thrust is can produce? Someone told me it hit 127,000lbs... At that amount of thrust would not that be considered a redline and constitute a burnt up engine?
747Classic beat me to it with the link. Triple red line indications, but apparently the engine survived.
Quoting Boeingfever777 (Thread starter): Does GE even sell engines to Boeing that have alloy that can with stand that?
The certification engine must have been a production item, so any GE90-115B could possibly be pushed that far, but no guarantees from GE of course.
Rated takeoff thrust in service remains 115,000 lb.
Boeingfever777 From United States of America, joined Jul 2009, 409 posts, RR: 56 Reply 3, posted (3 years 9 months 1 week 5 days 13 hours ago) and read 5830 times:
KELPkid From United States of America, joined Nov 2005, 5962 posts, RR: 4 Reply 4, posted (3 years 9 months 1 week 5 days 12 hours ago) and read 5798 times:
So, how high would the thrust be bumped up on the occasion of, say, a Maximum Gross Weight takeoff at a hot and high field with an engine failure past V1?
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
Jetlife2 From United States of America, joined Jul 2006, 214 posts, RR: 25 Reply 5, posted (3 years 9 months 1 week 5 days 8 hours ago) and read 5709 times:
Quoting KELPkid (Reply 4): So, how high would the thrust be bumped up on the occasion of, say, a Maximum Gross Weight takeoff at a hot and high field with an engine failure past V1?
The FADEC software produces rated thrust up to the cornerpoint (ambient day-altitude combination ). So, simplifying, if this occurred at Sea Level Static Standard Day (59 F , 15 C), and the FMC/FADEC was set to Takeoff, the engine would output 115,000 lb.
Above cornerpoint (Hot and/or High ), the engine is constrained by various limits to protect N1, N2 or EGT. So it will output less thrust. With a N1 controlled engine there is an N1 schedule that tells it what N1 to run to to respect those limits, then the thrust falls out as a product.
Starlionblue From Hong Kong, joined Feb 2004, 15904 posts, RR: 66 Reply 6, posted (3 years 9 months 1 week 5 days 7 hours ago) and read 5668 times:
Quoting Jetlagged (Reply 2): The certification engine must have been a production item, so any GE90-115B could possibly be pushed that far, but no guarantees from GE of course.
Hehe yes. Also the wear and tear would probably be rather detrimental to useful life. And it would need an inspection immediately.
On a related note, the MiG-25 engines could push the aircraft beyond Mach 3 only once. Doing so pretty much destroyed the engines.
"There are no stupid questions, but there are a lot of inquisitive idiots." - from Citadel by John Ringo
A380900 From France, joined Dec 2003, 1036 posts, RR: 1 Reply 7, posted (3 years 9 months 1 week 5 days 6 hours ago) and read 5660 times:
Could the A380 be fitted with four of GE90-115? I know there's no point but from a technical standpoint, these engines are the same size and weight as the GP7200, are they not?
Then if you used them at the thrust required for the A380, would they burn about the same amount of fuel? Would they make the same noise?
I understand there is no point in not using the specially built engines but I was just wondering how similar a result 4 GE90s could produce.
Another way to put the question is: what are the main differences between the GP7200 and the GE90?
Fxramper From United States of America, joined Dec 2005, 7048 posts, RR: 92 Reply 9, posted (3 years 9 months 1 week 4 days 20 hours ago) and read 5505 times:
Fantastic video of testing on GE90-115B (chronological).
Tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 10, posted (3 years 9 months 1 week 4 days 8 hours ago) and read 5381 times:
Quoting A380900 (Reply 7): Could the A380 be fitted with four of GE90-115?
In theory, yes.
Quoting A380900 (Reply 7): I know there's no point but from a technical standpoint, these engines are the same size and weight as the GP7200, are they not?
The GE90-115 is bigger and heavier than the GP7200.
Quoting A380900 (Reply 7): Then if you used them at the thrust required for the A380, would they burn about the same amount of fuel?
More. The SFC on turbofans goes down with increasing thrust. The GE90 and GP7200 should be pretty comparable at full thrust SFC, but you'd have to throttle the GE90 back more to match required thrust for the A380, so it would take a bigger efficiency hit.
Quoting A380900 (Reply 7): Would they make the same noise?
The GE90 should make less, since it would be spinning slower for equal thrust.
Quoting A380900 (Reply 7):
Another way to put the question is: what are the main differences between the GP7200 and the GE90?
747classic From Netherlands, joined Aug 2009, 1815 posts, RR: 11 Reply 11, posted (3 years 9 months 1 week 4 days ago) and read 5289 times:
Quoting A380900 (Reply 7): Could the A380 be fitted with four of GE90-115? I know there's no point but from a technical standpoint, these engines are the same size and weight as the GP7200, are they not?
NO, the GE90-115 is far to heavy and also the power rating is far to high, compared to the GP2700.
A better comparison could be the GP7277 and the GE90-77B
GE90-77B, 81.700 lbs T/O thrust, dry weight 7892,5 kgs, certification date 22 jan 1997.
GP7277, 80.290 lbs T/O thrust, dry weight 6718 kgs, certification date 8 april 2003
Cobra27 From Slovenia, joined May 2001, 995 posts, RR: 0 Reply 12, posted (3 years 9 months 1 week 3 days 17 hours ago) and read 5203 times:
Quoting Starlionblue (Reply 6): On a related note, the MiG-25 engines could push the aircraft beyond Mach 3 only once. Doing so pretty much destroyed the engines.
I highly doubt that, during egipt israel war, there were some mach 3 flights over israel with russian pilots on board. The earlier engine had only a bout 300 hours flight time. I really don't think they changed engine after every flight. Afterburner works with almost no relation to turbine. And SR-71 with its ram engine flew for hours over mach 3
Do you have any source to support that claim?
KELPkid From United States of America, joined Nov 2005, 5962 posts, RR: 4 Reply 13, posted (3 years 9 months 1 week 3 days 16 hours ago) and read 5179 times:
I highly doubt that, during egipt israel war, there were some mach 3 flights over israel with russian pilots on board. The earlier engine had only a bout 300 hours flight time. I really don't think they changed engine after every flight. Afterburner works with almost no relation to turbine. And SR-71 with its ram engine flew for hours over mach 3
Do you have any source to support that claim?
I read Viktor Belenko's story, "MiG Pilot", and he confirmed the fact that pushing the MiG 25 to Mach 3 would burn up the engines...the aircraft had the capability, but it was only supposed to be used upon intercepting high speed Western aircraft.
The CIA knew this, too, from the Arab/Israeli conflicts, as they had satellite photos of engine changes happening after these flights
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
Also from here: http://www.wvi.com/~sr71webmaster/mig25.html
:# Pilots were forbidden to exceed Mach 2.5. There was a total of three engine instruments and the airspeed indicator was redlined at 2.8 Mach.
# Above Mach 2.8 the engines would overheat and burn up. The Americans had clocked a Mig-25 over Israel at Mach 3.2 in 1973. Upon landing in Egypt, the engines were totally destroyed. We did not understand that the engine destruction was inevitable.
Quoting Cobra27 (Reply 12): And SR-71 with its ram engine flew for hours over mach 3
A whole different animal to the MiG-25. Much better adapted to high speed flight.
[Edited 2009-09-12 18:26:57]
[Edited 2009-09-12 18:30:01]
[Edited 2009-09-12 18:30:47]
[Edited 2009-09-12 18:31:14]
"There are no stupid questions, but there are a lot of inquisitive idiots." - from Citadel by John Ringo
KELPkid From United States of America, joined Nov 2005, 5962 posts, RR: 4 Reply 15, posted (3 years 9 months 1 week 3 days 3 hours ago) and read 5036 times:
Quoting Starlionblue (Reply 14): Quoting Cobra27 (Reply 12):
And SR-71 with its ram engine flew for hours over mach 3
A whole different animal to the MiG-25. Much better adapted to high speed flight.
[Edited 2009-09-12 18:26:57]
That's debatable to a degree Sure, the SR-71 was designed to fly at >Mach 3 (the SR-71's top speed in level flight is still classified, believe it or not). Ask an SR-71 pilot about an "unstart" sometime... quite the hair-raising event. Then again, you have to remember that Kelly Johnson and his staff in the Skunkworks pulled this project off in less time than anyone thought possible, and way under budget, using good old-fashioned slide rule engineering. I doubt that this kind of "can do" engineering would be seen today, unfortunately...
BTW, I tried to peer into the SR-71 cockpit at the Evergreen Aviation Museum in MMV, but it is impossible to get close enough to see the top of the Mach indicator (due to the strategic placement of the steps leading up to the cockpit, and the fact that they won't let you get all the way up to the coaming of the cockpit).
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
DocLightning From United States of America, joined Nov 2005, 16936 posts, RR: 57 Reply 18, posted (3 years 9 months 1 week 2 days 15 hours ago) and read 4908 times:
Quoting 747classic (Reply 11):
GE90-77B, 81.700 lbs T/O thrust, dry weight 7892,5 kgs, certification date 22 jan 1997.
GP7277, 80.290 lbs T/O thrust, dry weight 6718 kgs, certification date 8 april 2003
Wow. That's a huge weight reduction. I wonder how SFC compares.
It also leads one to wonder if the GP7277 would be a good candidate to replace the GE90-77B should Boeing decide to re-engine the 777.
Quoting Starlionblue (Reply 14): pon landing in Egypt, the engines were totally destroyed.
Then how did the plane land? I don't understand what "totally destroyed" meant. Obviously the engine continued to operate well enough to allow the plane to safely land.
Starlionblue From Hong Kong, joined Feb 2004, 15904 posts, RR: 66 Reply 19, posted (3 years 9 months 1 week 2 days 9 hours ago) and read 4848 times:
Quoting DocLightning (Reply 18): Quoting Starlionblue (Reply 14):
pon landing in Egypt, the engines were totally destroyed.
Then how did the plane land? I don't understand what "totally destroyed" meant. Obviously the engine continued to operate well enough to allow the plane to safely land.
Heh good point. I guess the author meant that they were still operating but needed a complete rebuild before flying again.
"There are no stupid questions, but there are a lot of inquisitive idiots." - from Citadel by John Ringo
Tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 20, posted (3 years 9 months 1 week 2 days 8 hours ago) and read 4826 times:
Quoting DocLightning (Reply 18):
Then how did the plane land? I don't understand what "totally destroyed" meant. Obviously the engine continued to operate well enough to allow the plane to safely land.
Something might have been lost in translation, but the variable that virtually always goes south first on an engine due to overpower is the EGT margin. You only run into that during very high power settings. So, unless you took it up to max thrust during the descent/approach/landing, it's entirely possible for you to have an engine that's "totally destroyed" in the sense that it can never again meet its performance requirements, but still works well enough to get you home to land.
Jetlife2 From United States of America, joined Jul 2006, 214 posts, RR: 25 Reply 21, posted (3 years 9 months 1 week 1 day 13 hours ago) and read 4673 times:
Quoting JetMech (Reply 8): Didn't GE have to develop a proprietary alloy for the LP shaft due to the high torque loads?
Yes : I quote from an (old) press release (public domain)
GE1014, the new high-strength steel alloy for the fan mid-shaft, significantly increases torque capability. As a result, the diameter of the mid-shaft remains the same, precluding modification of other core components. GE1014 chemistry was identified in 1996, and full-scale melt practice was defined in mid-1998. Materials property testing was completed in late 1999, at approximately the same time the first full-scale forgings were delivered. Prototype shafts have been produced and finish-machined to confirm manufacturability.
Prebennorholm From Denmark, joined Mar 2000, 6039 posts, RR: 55 Reply 22, posted (3 years 9 months 1 week 1 day 10 hours ago) and read 4632 times:
Quoting Boeingfever777 (Thread starter): I want to know what is the max thrust is can produce? Someone told me it hit 127,000lbs... At that amount of thrust would not that be considered a redline and constitute a burnt up engine?
Turbofan engines have several red lines, most important max EGT, N1 and N2.
Max certified thrust is a product of the first red line to be reached at standard sea level atmosphere, 1013 millibar and 15 deg C (59 deg F).
For certification tests all engines must demonstrate significant exceedings of all red lines in order to demonstrate a safety margin in commercial service.
In a jet engine you practically just pump in more fuel, and the engine produces more thrust, until it fails - until mechanical failure or fried turbines. All commercial engines have been tested successfully at considerably higher thrust than the max certified thrust while exceeding the red lines by well calculated values. For the GE90-115B that test happened to max out at 127,900 lbs.
That means that one GE90-115B has survived that treatment. It doesn't mean that it is a "safe" 127,900 lbs engine. It means that it is one of many tests which have convinced the FAA that rated at 115,000 lbs it is safe enough to be used for commercial flight.
Always keep your number of landings equal to your number of take-offs, Preben Norholm
Tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 23, posted (3 years 9 months 1 week 1 day 7 hours ago) and read 4597 times:
Quoting Prebennorholm (Reply 22): For certification tests all engines must demonstrate significant exceedings of all red lines in order to demonstrate a safety margin in commercial service.
This isn't unusual to engines...it's fairly common for people to confuse certified capabilities with actual. To say something is certified to a particular limit (thrust, stall speed, load factor, etc.) means that you guarantee (to some defined probability) that the thing will perform to that level after normal wear and tear at the end of its life, possibly with other failures. As a result, new or "mid life" components are almost always capable of exceeding their certified values.
ManuCH From Switzerland, joined exactly 8 years ago today! , 2977 posts, RR: 51 Reply 24, posted (3 years 9 months 1 week 1 day 4 hours ago) and read 4563 times:
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quite the hair-raising event. Then again, you have to remember that Kelly Johnson and his staff in the Skunkworks pulled this project off in less time than anyone thought possible, and way under budget, using good old-fashioned slide rule engineering. I doubt that this kind of "can do" engineering would be seen today, unfortunately...
(due to the strategic placement of the steps leading up to the cockpit, and the fact that they won't let you get all the way up to the coaming of the cockpit).
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