AN ACR MLG CREW INADVERTENTLY PUT 'DUFER' VICE INTO ITS FMC.

Narrative

ENRTE TO PDX FROM DEN. NEAR BOI CLRED DIRECT DUFUR DIRECT PDX. INADVERTENTLY SPELLED DUFER IN FMCS. NOTE: DUFER IS 14.1 DME; ILS RWY 16R SEATTLE. SINCE THE COURSE SEEMED REASONABLE; I DID NOT DOUBLE CHK THE SPELLING OR RTE DEV DUFER TO PDX. A LESSON LEARNED!! I AM SURPRISED THAT 2 INTXNS WOULD BE SO CLOSE WITH SIMILAR NAMES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTING CAPT SAYS THAT THE MISTAKE WAS FOUND BY THE ARTCC CTLR WHO ASKED 'WHERE ARE YOU GOING?' THE RPTR REALIZES THAT THE FAA IS RUNNING OUT OF FIVE LETTER DESIGNATORS; BUT WISHES THAT THEY COULD BE SEPARATED BY A FEW THOUSAND MI IF IT IS NECESSARY TO HAVE SIMILAR SOUNDING WORDS WITH DIFFERENT SPELLINGS. SUPPLEMENTAL INFO FROM ACN 258669: FLT WAS CLRED PRESENT POS DIRECT 'DUFUR' DIRECT PDX. 'DUFER' WAS INADVERTENTLY TYPED INTO THE FMCS. 'DUFER' IS 14.1 DME ON THE SEA ILS RWY 16R APCH. ROM THE CURRENT POS TO 'DUFUR' THE NEW COURSE SEEMED REASONABLE. CONTRIBUTING TO THE SIT WAS THE FACT THAT 'DUFER' AND PDX 'DUFUR' WERE BOTH BEYOND THE EHSI MAP SCALE OF 320 NM.