All CF34-3A engines with Serial Numbers 305001 – 350525 and a certain part number rear compressor spool installed, have until December 31, 2012, to replace this spool. Per GE BJ SB 72-0175, this is another item that used the Electromechanical Etching process during manufacturing to stencil information on the components. If your engines are subject to this SB, submit your engine S/N, times/cycles and P/N-S/N of the Rear Drum to me and we'll see if we can't pursue a different avenue.