|Quoting TimT (Reply 6):|
CFM's are way too cool-- on our 319-320 fleet the manual specs 2 (two) different CFM's. Got on and need the other? Change the FADEC! There you go. Might be able to do that on the IAE too. Just don't have any experience with them.
The two 'different' CFM56-5B engines for the A320 family include a "/P" series and a series not designated with the "/P" suffix. I believe the /P suffix indicates that some of the high pressure rotors employ a more efficient "3-D" (misnomer) airfoil section that non-/P engines lack. This is an actual hardware difference on the rotors and is of course independent of the FADEC installed. If you are familiar with the AMM (and it looks like you might be) the /P engine sometimes has different serviceable limits than the non-P counterpart.
- Each engine serial number has an "N1 modifier" associated with it. This N1 modifier is a measure of how a given engine performed in a test cell. When engines are moved between aircraft and may require a different thrust installation this N1 modifier is used in calculations to uprate or derate a given engine at an appropriate level.
- The thrust level of an engine is changed (perhaps more accurately "programmed") by installing a "data plug" that screws onto the ECU and conveys program information that sets the engine thrust output to the level desired by the operator. A given spare engine may have multiple data plugs tailored to its specific engine serial number and kept on standby for a later date if/when a change in thrust or new installation is desired for the engine.
- Each engine has an Engine Data Plate
This data plate is required for flight per FAR
. Following a thrust level change as per above or the running of an engine in a test cell at any time the observed N1 modifier status and current thrust configuration are stamped onto the data plate.
Aside from the /P and non-/P difference between CFM56-5Bs, the only hardware difference (if you don't count the programmed thrust plug) is an additional sense line installed on the A319 (CFM56-5B6 or -5B6/P). This sense line is not installed on the A320 (CFM56-5B4) or A321 (CFM56-5B3) variants of the engine.
As far as hardware similarity is concerned (within a /P or non-/P family), the A320 and A321 have the same engine with exception of different thrust plug programming. The A319 configuration has an extra sense line installed. Both configurations can be achieved from the same engine serial number with no more than a couple hours of work to remove or install the sense line depending on which way you wish to go. No change (apart from screwing in a different thrust plug) is necessary to go A320<-->A321
|Quoting Dl757md (Reply 13):|
Quoting A/c train (Reply 9):
Fan arrangements etc are simpler on V25.
I've done many fan blade lubes on both engines. The V2500 may have a slightly simpler fan design but the removal and installation on the CFM56-7 is far easier and quicker.
CFM56-5B is the relevant model if we are talking about an apples-apples narrowbus comparison.
|Quoting Dl757md (Reply 16):|
The CFM56-7 (which is what I was referring to) on the next generation 737 has 24 wide chord blades just like the V2500. I wouldn't compare a CFM56-3 engine with 36 blades to the V2500. They're two different generations of powerplant. The only fair comparison of the V2500 to a CFM56 is to the -7 series.
In my opinion the only fair comparison is the -5B to the V2500. The V2500 is not available for comparison to a -7 due to the fact that the engines can't be installed on a common airframe for evaluation. I do understand where you are going with the similar appearance of the -7 and V2500 blades but no market competition exists between the -7 and V2500.