747classic From Netherlands, joined Aug 2009, 1779 posts, RR: 11 Posted (1 year 1 day 17 hours ago) and read 4340 times:
Is there some news about the progress at the GEnx-2B67 as installed at the 747-8 series ? Any good news about restoring the TSFC-shortfall on this engine will benefit the present 747-8 sales effort by Boeing.
According one of the latest in-depth articles (Nov. 2011) about this engine upgrade package the following was mentioned :
"GE has begun manufacturing the hardware meant to demonstrate the -2B’s single PIP, expected to go to test in February or March next year and fly on the company’s Boeing 747 test bed during the third quarter. GE expects FAR Part 33 certification in April 2013 and FAR Part 25 approval in October 2013.
GE expects the -2B’s PIP to result in a 1.7- to 2-percent gain in fuel-burn efficiency".
See : http://www.ainonline.com/aviation-ne...g-hard-meet-genx-fuel-burn-targets
It's now May 2012, the engine must have been tested on the test bench , any results ?
747classic From Netherlands, joined Aug 2009, 1779 posts, RR: 11 Reply 2, posted (1 year 1 day 14 hours ago) and read 4280 times:
- Actual TSFC shortfall of the GEnx-2B is approx. 2,7 % .
- The 747-8F aerodynamic performance is 1% better than specification.
- Expected gain of PIP is 1,7-2,0 %.
After implementation of the PIP both the 747-8F and -8I will be on or even slightly better than spec. The engine is however still 0,7-1,0 % below spec.
The 747-8 OEW overweight issue is temporally solved by increasing all maximum operating weights, after the discovery of additional structural margin in the load-survey tests. If the weight saving program is successfully finished the payload -range will be increased even further (above spec.)
Quoting sweair (Reply 1): If they get this engine right, it might just lure Airbus to re engine the A330..But that would need more thrust?!
The thrust of the GEnx-2B can be increased (max . 70.000 lbs ??) if the booster stage is improved/changed like is done at the PIP2 of the 787 engine (GEnx-1B) as mentioned in the linked article in the first posting of this thread.
747classic From Netherlands, joined Aug 2009, 1779 posts, RR: 11 Reply 7, posted (1 year 1 day 10 hours ago) and read 4160 times:
Quoting ferpe (Reply 3): If the weight saving program is successfully finished the payload -range will be increased even further (above spec.)
So where is todays delivered frame, what was the original spec and where would we land? I have 7700nm at spec Pax Bags right now, OK?
Initial aircraft are 2.3-2.7 tonnes (5,000-6,000 lbs) overweight since the revised wing design after 2005.
Target (2008 estimate) is 8000nm with 487 pax + bags.
747-8I -Payload-range -2008
Weight saving target is about 5000 lbs.
Quoting ferpe (Reply 4): Where do you have the -2B spec TSFC vs the -1B original spec? I have a notion of the -1B spec saying 0.53 at best FL (390), where would the -2B be then?
ferpe From France, joined Nov 2010, 1769 posts, RR: 57 Reply 9, posted (1 year 1 day 9 hours ago) and read 4088 times:
Quoting 747classic (Reply 7): In following article a (target)TSFC of the GEnx-2B engine on the 747-8 is noted as 0.274 lb/lbt/hr :
Thanks for the payload-range chart and for the range info Stitch. Any TSFC below 0.3 is for static thrust, ie lineup on runway at full TO thrust. Cruise SFCs are always worse and lie for the present engines between 0.5 -- 0.6 .
OK, then I stick to my previous figures (about 0.54 for the -2B )
sweair From Sweden, joined Nov 2011, 1543 posts, RR: 0 Reply 10, posted (1 year 1 day 7 hours ago) and read 4062 times:
Ferpe, what do you think of a A330 based A310 sized 757 replacement? Hang the Genx 2b on it, range would only have to be TATL capable. There will be a huge gap from A321neo /739 max up to 788 and 358 even worse.
As I understand the A310 had the same cross section as the 330? Would it be possible to build a middle range on the 330 frame, wings would be a problem but engines would be the same as 748, maybe de rated though. OEW 70-80t..
There is a niche or a gap that will be needed to fill imo, a gap from A321 OEW to 788 OEW, sure 767 and A332 will fly for a while yet, but in 10 years time? 240 seats and maximum 4500nm ranges..
ferpe From France, joined Nov 2010, 1769 posts, RR: 57 Reply 11, posted (1 year 1 day 5 hours ago) and read 4011 times:
Quoting sweair (Reply 10): Ferpe, what do you think of a A330 based A310 sized 757 replacement?
I think it exist already, you typically see aircrafts sizes in 30 seat increments, the 321/MAX9 are 210-220 planes, the 788 is a 220-240 plane, from 260 seats the 358 cuts in. The 788 already have the better of the GEnx engines, it is a frame in very high rate production = low building cost down the line and it will get it's OEW and performance tuned to an optimum, there is some 1000 frames or more to spread those continuous engineering costs on.
It is a very modern and forward looking design so anything that shall compete with it has to be top notch, a warmed over 310 with GEnx engines is not.
Airbus seems to have seeded this space to Boeing, they will focus on the 220- and 250+ space it seems letting Boeing play alone in between.
sunrisevalley From Canada, joined Jul 2004, 3946 posts, RR: 4 Reply 12, posted (1 year 1 day 1 hour ago) and read 3947 times:
Quoting Stitch (Reply 8): Using the December 2011 ACAP, at the same MZFW as June 2010 (640,000 pounds), range is about 6150nm.
I believe I read ( but can't remember where) that the Dec 2011 ACAP L/R table was based on a "normalised" OEW , that is what the OEW is planned to be after the present 5 to 6K pounds over weight is removed.
sweair From Sweden, joined Nov 2011, 1543 posts, RR: 0 Reply 13, posted (1 year 18 hours ago) and read 3884 times:
Quoting ferpe (Reply 11): Airbus seems to have seeded this space to Boeing, they will focus on the 220- and 250+ space it seems letting Boeing play alone in between.
I just had the idea when I looked at the A310, 240 seats and one model had TATL range, IMO a perfect middle range shuttle aircraft, if it could be done in a modern form. 2-4-2 is a nice layout for TATL trips. If it was aimed at below 4500nm trips I think it would find plenty of customers, we never know how much fuel will cost in 10 years time. If 80t can fly 240 people it should be cheaper than 260 seats in 112t 788.
Anyway I like to wonder off in wild ideas, not too serious.
Stitch From United States of America, joined Jul 2005, 26681 posts, RR: 83 Reply 19, posted (12 months 4 days 9 hours ago) and read 3526 times:
GE seems to want a very strong RoI on any engine program they enter into, which is understandable considering how expensive these programs are. As such, I don't really see them interested in a pure re-engine option and would prefer to also have a healthy new-build program.
I do not share the enthusiastic prospects some do for what an A330 re-engine would do for future sales. I believe the A330's future will trend along the lines of the 767 - mostly freighter orders with some top-up passenger orders for large operators. As such, the sales figures are too low to support a new engine option.
GE has already re-engined the C5 with the CF6-80C2, also known as C5 RERP. This adds thrust, climb rate, payload and dramatic fuel burn benefit. These installations are in process. No likelihood of another re-engine of the C5.
Additional to this delay : the prolonged grounding of the 787, effectively arresting the tests for engine/airframe certification (FAR part 25) of the preceding GEnx1B/PIP2, could have a negative effect on the time line of the GEnx-2B/PIP certification.
AFAIK no GEnx-2B PIP test flights have been performed by any of the two General Electric testbeds up to now.