There have been references in recent threads to the future 737NG/A320 replacement aircraft. The engines used on the replacement narrow bodies will be key.
This week’s Aviation Leak has an article about narrow body engine development. In that article, 10-15% lower TSFC is quoted as the goal for the CFM derived improvement engine named LEAP56. This engine should enter service around 2015.
Given the fact that the CFM56 is already a 25 year old design, and the new engine won’t enter service for 7 more years, doesn’t 10-15% seem modest? Then again, maybe yields in the narrow body market won’t justify expense for an all new engine, I don’t know.
I can’t prove it, but it seems to me that from about 1960 to the early 1990’s, SFC improved at a rate of a little less than 1% a year. (Compare the burn per seat of a 707 to an NG/A320.) Can this pace be maintained? My “rough” numbers seem to indicate the LEAP56 goal is only about 1/2 what has historically been achieved.
By: Schorsch - 24th March 2008 at 17:53
For what it’s worth, in February 2008, CFM clarified that its Leap56 predicted gains are compared to the latest CFM56 Tech Insertion configuration. CFM says it is targeting 10 – 15 percent lower specific fuel consumption; 15 percent lower maintenance costs; 25 percent longer initial on-wing life; a 10 – 15 decibel reduction in noise; and a 60 percent reduction in NOx emissions.
That would suffice to power a “next generation” single aisle.
I guess P&W will be sooner on the market with its GTF, while not sure if the GTF can bring similar gains then.
It will be interesting if any other engine company enter the market (Rolls Royce, MTU).
By: Arabella-Cox - 24th March 2008 at 16:43
Is Leap56 the answer?
For what it’s worth, in February 2008, CFM clarified that its Leap56 predicted gains are compared to the latest CFM56 Tech Insertion configuration. CFM says it is targeting 10 – 15 percent lower specific fuel consumption; 15 percent lower maintenance costs; 25 percent longer initial on-wing life; a 10 – 15 decibel reduction in noise; and a 60 percent reduction in NOx emissions.
By: Schorsch - 25th October 2007 at 12:40
Sorry to show my ignorance. Is a GTF the same sort of concept as the Unducted Fan test flown on a Boeing 727 a few years ago?
Thanks in anticipation for your time and trouble.
Be lucky
David
A GTF is a Geared Turbo Fan, means a gearbox between low pressure spool and fan disc allows the fan to rotate slower and the LP-compressor faster, thus gaining on each’s efficiency. It isn’t a revolutionary concept, but is supposed to increase fuel efficiency by some percent.
CFM56 may be 25 years old, but it is continuously improved. The CFM56-7 (B737NG) don’t have to much in common with the -3 (B737-3/4/5) or -2 (DC-8, B707). Therefore it would be nice to know compared to which engine they will gain 15%. I don’t think this is meant as saving compared to latest CFM56 variants.
I read an article myself about LEAP56 and understood it was amodest improvement program. The fact that they don’t make it a new engine despite the serious interest of the market shows that it doesn’t really involve new technologies.
The P&W6000 GTF has some hopes of powering an intermediate A320 replacement. The A320 has the advantage of providing enough space beneath its wing. The LEAP56 engine might be a similar alternative for updated B737NG, but I think that Boeing needs to update the airframe, too, which doesn’t make too much sense in case of the A320.
By: AvgasDinosaur - 25th October 2007 at 12:32
Sorry to show my ignorance. Is a GTF the same sort of concept as the Unducted Fan test flown on a Boeing 727 a few years ago?
Thanks in anticipation for your time and trouble.
Be lucky
David
By: Ship 741 - 24th October 2007 at 18:54
I guess nobody much cares about this topic, or perhaps there isn’t a lot to say. Nevertheless, I find it interesting.
There was a related article in Av. Week this week, talking about the competitor to Leap56, the P&W GTF, (Geared Turbo Fan), “winning” a competition to be on a new Mitsubishi RJ.
In the article, P&W states the advantages they see regarding the GTF over conventional power, and state that they have been investing about $100 million/year for some time on this technology.
Pratt is quoting only about a 12% improvement in burn, with another 5-7% to come by 2020 with further development. It seems as if neither competitor has an advantage, with GE talking the same ballpark figures, ie., 10-15%.
It’s long term stuff, but someone is going to emerge in the next few years as the engine maker of choice for the A320/737NG replacement aircraft, which in and of themselves are interesting.
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September 14, 2007 at 10:41 am