WDB ON OCEANIC FLT MIS-PROGRAMS INS. HDG DEV.

Narrative

ON A FLT FROM FRA; GERMANY; TO EWR USING INS AS THE PRIMARY NAV SYS; WE APCHED THE N ATLANTIC MNPS FIX 59N; 10W. REACHING THIS FIX I MADE A POS RPT TO SHANWICK RADIO AND CONTINUED NAVIGATIONAL PLOTTING ON THE PLOTTING CHART. AT THIS POINT; I NOTICED THAT THE ACFT HAD MADE A R TURN AS MUCH AS 70 DEGS DEV OFF COURSE (HDG). I IMMEDIATELY DISCONNECTED THE AUTOPLT AND MANUALLY TURNED THE ACFT AROUND TOWARDS THE NEXT FIX IN LINE; 61N; 20W. AFTER CHKING THE NEXT WAYPOINT 61N; 20W; I NOTICED THE COORDINATES OF 61N; 20E HAD BEEN INCORRECTLY ENTERED. AFTER THAT WE THEN RE-VERIFIED THE REST OF THE WAYPOINTS AND THE ACFT CONTINUED AS FLT PLANNED TO EWR WITHOUT FUTURE INCIDENCE. PRIOR TO THE DEP FROM FRA; NUMEROUS MAINT ITEMS HAD TO BE CORRECTED. ONE OF THOSE ITEMS WAS A FAILED AIR DATA COMPUTER THAT COULD HAVE CONTRIBUTED TO THE WRONG COORDINATES BEING ENTERED. NUMEROUS MAINT PERSONNEL WERE PRESENT INSIDE THE COCKPIT DURING THE CRITICAL PHASE OF THE PROGRAMMING THE INS'S; AND INTERRUPTIONS FROM THEM. DURING THESE INTERRUPTIONS; THE WRONG COORDINATES COULD POSSIBLY HAVE BEEN ENTERED INCORRECTLY. SUPPLEMENTAL INFO FROM ACN 251754: CAPT HAD EARLIER GIVEN OCEANIC NAV LOG AND PLOTTING CHART TO FO (PF) AND ASKED HIM TO DO THESE DUTIES. FO; WHO WAS RELATIVELY NEW TO THE AIRPLANE AND OCEANIC NAV (APPROX 150 HRS IN TYPE); HAD HIS HEAD DOWN AND WAS READING THE 59N; 10W POS RPT TO SHANWICK CTL AND DID NOT NOTICE CONTINUING TURN UNTIL SUN BEGAN TO COME IN R SIDE COCKPIT WINDOWS. DURING PREFLT AND LOADING AND CHKING INU'S WE WERE DEALING WITH SEVERAL MAINT PROBS AND CUSTOMER SVC PROBS. CAPT WAS TRYING TO 'MICRO-MANAGE' THINGS THAT HE SHOULD HAVE LEFT TO OTHER PEOPLE TO HANDLE.