Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
What CFM-56 Stands For?  
User currently offlineLuis777 From Mexico, joined Aug 2004, 89 posts, RR: 0
Posted (9 years 11 months 6 days 2 hours ago) and read 14754 times:

Hello, all what I know about this engine is that CFM is a joint venture between General Electric and SNECMA. General Electric use to name their engines CF and I think that the C is for Compressor and F means Fan, but I'm not sure. About SNECMA I know that they always use the M for "Moteurs" in French language. Does someone can correct me please?
Talking about the numbers I think that GE choose the 6 because this engine could be a derivate of their CF6 engine, but why 6? and SNECMA choose the 50 because they utilize numbers like M80, M60, M100, etc. What do you think about this? I made a search on the web but I didn't find anything.

Regards

LG

12 replies: All unread, jump to last
 
User currently offlineAir2gxs From , joined Dec 1969, posts, RR:
Reply 1, posted (9 years 11 months 6 days 1 hour ago) and read 14637 times:

From the CFM Website:

CFM is not an acronym, so it doesn’t stand for anything. The company (CFM), and product line (CFM56), got their names by a combination of the two parent companies’ commercial engine designations: GE’s CF6 and Snecma’s M56.

The internet is a wonderful thing.

http://www.cfm56.com/excel/index.html


User currently offlineLuis777 From Mexico, joined Aug 2004, 89 posts, RR: 0
Reply 2, posted (9 years 11 months 5 days 17 hours ago) and read 14255 times:

Thanks a lot Air2gxs, I didn't notice that info on cfm56 page the first time I entered there, what a shame :p .

And yes, I agree, the internet is a wonderful thing.

Regards

LG


User currently offlineBuzz From United States of America, joined Nov 1999, 697 posts, RR: 22
Reply 3, posted (9 years 11 months 5 days 11 hours ago) and read 14207 times:

Hi Luis777, Buzz here. Well, in the mid '80s when UAL replaced the JT3D engines on the DC-8's with CFM56 engines we figured that CFM stands for "Creates Forward Motion". I think i recall that it stood for the english equivalent of "Commercial Fan Motor".

It took a while to get used to the new engines, they were a lot slower to start (that's a mighty big fan to accelerate) and Oscar O. had a handful of melted turbine blades to show us what happens when a pilot starts the engine with a tail wind, and clicks the fuel lever on without checking to see if the N1 is turning. (don't do that)

And the fuel nozzles ("injectors" back then) would cause quite a loud Buzz - enough to feel it in your chest - while the engine was accelerating up to idle speed. But when it was at idle you could walk up beside it (carefully!) to look for leaks and she'd be running smoothly.

g'day
Buzz Fuselsausge: Line Mechanic by night, DC-3 Crew Chief by choice, taildragger pilot for fun.


User currently offlinePhollingsworth From United Kingdom, joined Mar 2004, 825 posts, RR: 5
Reply 4, posted (9 years 11 months 5 days 6 hours ago) and read 14151 times:

Talking about the numbers I think that GE choose the 6 because this engine could be a derivate of their CF6 engine, but why 6?

While I can offer no insight into why GE says that the naming is a CF6 derivative, I can say that the CFM-56 is not a CF-6 derivative in any sense other than it is a HBTF that came after the CF6. However, GE has historically named their commercial turbofans CF (CF6, CF34). I do know the project sat stagnate for over 10 years and that the GE-SNECMA partnership was a risk reduction choice. However, I don't know if both GE and SNECMA had independent programs for this thrust class prior to the formation of CFMI. The CFM-56 core is from the F-101, i.e. the B-1 bomber motor.


User currently offlineDfwRevolution From United States of America, joined Jan 2010, 962 posts, RR: 51
Reply 5, posted (9 years 11 months 4 days 22 hours ago) and read 14072 times:

While I can offer no insight into why GE says that the naming is a CF6 derivative, I can say that the CFM-56 is not a CF-6 derivative in any sense other than it is a HBTF that came after the CF6

GE, and other manufactures, build off the newest or previous generation of engine technology. The CFM56 built of the CF6 and M50, the GE90 built off the CF6, and the GENEX will build off the GE90.

The CFM56 and CF6 probably share very little, but they have a common design philosophy


User currently offlinePhollingsworth From United Kingdom, joined Mar 2004, 825 posts, RR: 5
Reply 6, posted (9 years 11 months 4 days 20 hours ago) and read 14043 times:

The CFM56 and CF6 probably share very little, but they have a common design philosophy

In the sense that the CFM56 shares the same design philosiphy with the TF39 and TF/CF34. The primary reason that the GENEX is based off of the GE90 tech is GE hasn't built an entirely new military jet engine since the GE90 was introduced and its subsequent upgrades. I believe the GP7000 core is also based off of the GE90


User currently offlineN243NW From United States of America, joined Jul 2003, 1626 posts, RR: 20
Reply 7, posted (9 years 11 months 2 days 19 hours ago) and read 13792 times:

I'm not sure about the CFM part of it, but I think I remember reading somewhere that the 56 represents the turbofan's 5.6:1 bypass ratio. Correct me if I'm wrong.
-N243NW  Big thumbs up

[Edited 2004-09-01 04:50:29]


B-52s don't take off. They scare the ground away.
User currently offlineBuckfifty From Canada, joined Oct 2001, 1316 posts, RR: 20
Reply 8, posted (9 years 11 months 2 days 18 hours ago) and read 13785 times:

There are a few derogatory versions of the name which are used by engineers and pilots alike. Unfortunately, too many kids read this site, cannot pollute their dear minds...

User currently offlineCdfMxTech From United States of America, joined Jul 2000, 1338 posts, RR: 27
Reply 9, posted (9 years 11 months 2 days 18 hours ago) and read 13779 times:

From CFM56-7 Factory Maintenance Training Manual

It is a product of CFMI. CFM International is a company
jointly owned by GENERAL ELECTRIC (GE) of the USA,
and SOCIETE NATIONALE D’ETUDE ET DE
CONSTRUCTION DE MOTEURS D’AVIATION
(SNECMA) of France.

Draw your own conclusions


User currently offlinePrebennorholm From Denmark, joined Mar 2000, 6388 posts, RR: 54
Reply 10, posted (9 years 11 months 1 day 22 hours ago) and read 13657 times:

SNECMA's engines are all named M plus a number.

They never finished development of their M56 engine project, which was mostly intended for the Dassault Mercure airliner.

Due to delays with M56 development the Mercure went to the air with P&W JT8D power, and it consequently never met the originally intended range capability.

They did develop a good fan unit, but went into great troubles with the M56 core. Then they joined forces with GE who had had Uncle Sam pay for development of the GE F-101 engine for the B-1 bomber.

Basically they joined the core of the F-101 with the fan of the SNECMA M56 engine project.

In GE terms I think that CF means "Commercial Fan engine", but I'm not sure. Anyway it's a fact that commercial fan engines from GE are named CF-x.

So basically they assembled the name CFM56 the same way as they put the engine together.



Always keep your number of landings equal to your number of take-offs, Preben Norholm
User currently offlineBrons2 From United States of America, joined Sep 2001, 3007 posts, RR: 4
Reply 11, posted (9 years 11 months 1 day 15 hours ago) and read 13602 times:

There are a few derogatory versions of the name which are used by engineers and pilots alike. Unfortunately, too many kids read this site, cannot pollute their dear minds...

Well hell, I appreciate a little adult humor, email them to me!



Firings, if well done, are good for employee morale.
User currently offlinePrebennorholm From Denmark, joined Mar 2000, 6388 posts, RR: 54
Reply 12, posted (9 years 11 months 22 hours ago) and read 13517 times:

While the name CFM56 is quite logical, then - slightly off topic - what does V2500 stand for?

"V" is the roman number five, which was the original number of manufacturers forming the consortium International Aero Engines (IAE). They were already reduced to four before the first test run, since FIAT stepped out.

"2500" is the originally intended max sea level thrust expressed in British pounds divided by ten.

So it would have been logical if an IAE V2530 had been named IAE IV3000 instead.



Always keep your number of landings equal to your number of take-offs, Preben Norholm
Top Of Page
Forum Index

Reply To This Topic What CFM-56 Stands For?
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
What Are These Intakes For On The 777? posted Wed Nov 1 2006 04:13:28 by Gh123
What Would You Buy For A First Plane. posted Tue Aug 15 2006 20:22:34 by Airfoilsguy
Was The P&W 2000 Meant To Compete With The CFM-56? posted Mon May 29 2006 19:31:12 by 747400sp
What's The Red Line For? posted Mon Dec 26 2005 14:57:44 by 777DadandJr
What Material Is Used For Aircraft Engines? posted Sat Dec 24 2005 19:48:06 by YYZACGUY
What Are They Used For? posted Wed Dec 14 2005 17:20:16 by ArcticTern
FL410: What Does It Stand For? posted Wed Oct 19 2005 11:43:38 by RootsAir
What Are The Requirements For 1.2.3.4 Stripes? posted Mon Jan 31 2005 23:04:39 by Imonti
What Does Ramtaf Stand For? posted Tue Dec 14 2004 03:10:02 by Groundstop
Difference Between CFM 56 And IAE V2500? posted Thu Feb 26 2004 20:10:59 by MEA321

Sponsor Message:
Printer friendly format