AMENDED RTE WAS NOT ENTERED IN FMC CAUSING THE ACFT TO FLY THE WRONG RTE.

Narrative

FLT; PIT DIRECT HPN; DEPARTED PIT AND SOON RECEIVED SEVERAL VECTORS AND ALT ASSIGNMENTS. REQUESTED DIRECT TO EWC; ADDITIONAL VECTORS WERE RECEIVED AND EXECUTED. SOON AFTER XING EWC VOR CTLR QUESTIONS OUR ROUTING. AFTER VERIFYING RTE FROM DISPATCH RELEASE; PDC ACARS MESSAGE AND ACTUAL FLT PATH; A SMALL CORRECTION WAS TAKEN TO FLY APPROPRIATE ROUTING. A SHORT DISCUSSION WITH CTLR ENSUED EXPLAINING THAT THIS ACFT HAS A POSSIBILITY OF HAVING SEVERAL FLT ROUTING AVAILABLE; RELEASE; ACARS; FMCS. THE CTLR ALSO POINTED OUT THE DEP ROUTING OUT OF PIT WAS ON A TEST BASIS AND SLIGHTLY DIFFERED FROM THE PREVIOUS STANDARD DEP TO THE N AND E. WE WERE SOON CLRED DIRECT TO DNY VOR AND THE FLT COMPLETED WITHOUT INCIDENT. OBVIOUSLY THERE EXISTS A WEAK AREA IN THE FMCS AND ACARS PDU DATA BANKS. CROSS-TALK SHOULD BE ABLE TO PREVENT ERRONEOUS FLT PLANS FROM BEING ACTIVATED WHEN DISCREPANCIES EXIST AND AN APPROPRIATE WARNING PRESENT TO PLT AND/OR PDC MONITORS. ALSO FMCS DATA BANK CHANGES SHOULD BE MUCH MORE TIMELY.