FLC OF MDT DEVIATED FROM FLT PLAN RTE DUE TO ACFT NAV COMPUTER NOT UPDATED TO A ROUTING CHANGE.

Narrative

FLT ENRTE FROM SBY; MD; TO PHL; PA. FLT SEGMENT WAS CLRED SBY V29 DQO DIRECT PHL. V29 CROSSES ENO (SMYRNA) VOR. AIRLINE; IN PAST 2 WKS; HAD GONE TO A NEW SYS OF FLT RELEASES (AFPAC) WHICH INVOLVES MORE ACCURATE SYS OF UTILIZING FUEL; WINDS ALOFT; AND ALSO CHANGES IN ALT AND MINOR CHANGES IN ROUTINGS WHICH HAD NOT BEEN INCORPORATED INTO THE KNS 660 NAV COMPUTER. CAPT MADE R TURN OVER ENO VOR TO INTERCEPT A RADIAL OFF OF OOD VOR WHICH WAS THE PREVIOUS ROUTING. PHL APCH ASKED IF CTR HAD GIVEN ACFT A TURN OFF THE AIRWAY. IT TOOK ONLY A MATTER OF SECONDS FOR CREW TO REALIZE THAT ACFT HAD DEVIATED FROM ATC FILED FLT PLAN. CAPT CALLED PHL APCH WHEN ARRIVING IN PHL ON LANDLINE. APCH INFORMED CAPT THEY HAD PASSED BEHIND ANOTHER ACFT IN AIRSPACE. ALSO SAID IT WAS SECOND TIME IN 1 WK. CAPT ACCEPTS RESPONSIBILITY FOR NOT CHKING ROUTING IN KNS 660 AGAINST ATC FLT PLAN. CALLED COMPANY AND INFORMED THEM THAT KNS 660 ROUTING WAS INCORRECT. COMPANY PERSONNEL SAID THEY HAD NOT HAD OPPORTUNITY OR MANPWR TO YET CHANGE PROGRAMMED FLT PLANS.