That's interesting... Harms' website always listed AA as one of the few operators of the actual CFM56-7B27, as opposed to most with the -7B26.
Thanks to AA
lawyers our Operating Manuals have gotten pretty *#%@ poor in the last decade or so. Officially everything was/is rewritten to "better correspond to the manufacturer's manuals" but what that really means is all descriptions are very brief and non-descriptive. My 738 OpMan lists the engines as simply CFM56-7.
Operationally, we have the capability of selecting a desired thrust rating [i.e. select what engine is on the plane that flight] with the choices being: 22k, 24k, 26k, and "27k Bump." AA
's TPS [Takeoff Performance System] computer program normally makes the "optimum" selection for us including derated thrust settings for each of the first three "engines."
"27k Bump" is a special situation. As told to me during 738 transition training a few years ago, AA
was the airline that pushed Boeing into getting the 738 noise certified at KSNA's second quietest noise slot [EE-exempt being the quietest] or AA
would not order the plane. In doing so Boeing had to push the engine envelope a little... hence the 27k thrust setting and the associated limitation that is may only be used at KSNA and only in conjunction with the special FMS programming called "Quiet Climb." My understanding is that other airlines have been offered and some have accepted [and paid for] this option, but that it is "standard equipment" on AA