LOSS OF #1 IDG WITH A RESULTING LOSS OF #1 HYD SYS. DIVERTED TO BOS.

Narrative

IN CRZ AT FL290 #1 IDG DISCONNECTED ITSELF. MAINT COORDINATOR ADVISED OK TO CONTINUE TO AMS. AS TOTAL KV WITHIN LIMIT; SAID THIS WAS COMPANY POLICY. HE DID NOT MENTION POSSIBLE CORRELATION WITH RECENT REPLACEMENT OF #1 HIGH SPD GEAR BOX. ABOUT 30 MIN LATER #1 HYD SYS FAILED; LEAVING LITTLE DOUBT IN CREW'S MINDS THAT #1 HIGH SPD GEAR BOX WAS FAILING. DIVERTED TO BOS FOR MAINT. LANDED AT 425K POUNDS (NORMAL MAX LNDG WT INTL) ON RWY 33L. VERY SMOOTH TOUCHDOWN; BRAKE APPLICATION BELOW 130 KTS TO PREVENT HEAT BUILDUP. EASY STOP. HAD EMER EQUIP STAND BY IN CASE OF BRAKE FIRE. GEAR BOX HAD FAILED AND FLT CREW ENTERED ACTUAL FAILURES (IDG AND HYD) IN LOG. ADVISED MAINT OF OVER WT LNDG AND BRAKE APCH SPD; BUT AS SO SPECIFIC DISCREPANCY DID NOT ENTER IN LOGBOOK. CREW FEELS MAINT SHOULD HAVE ADVISED OF POSSIBILITY OF HIGH SPD GEAR BOX FAILURE WHEN TOLD OF IDG DISCONNECT; AND PERHAPS SUGGESTED WE LAND TO HAVE IT CHKED PRIOR TO OCEAN XING. FLYING DOMESTIC LEGS AND CHKING AT EACH STOP UNTIL REPLACEMENT IS FEASIBLE IS ONE THING; FLYING UNITED STATES TO EUROPE IS QUITE ANOTHER. NOTE: BOS HAD SEVERAL RWY 33L TAXIWAY TURNOFFS CLOSED. BUT THEY WERE POORLY LIGHTED AND LIGHTING WAS RECESSED TOO FAR; ESPECIALLY HARD TO SEE ON A DARK; RAINY NIGHT. NOR DID TWR CAUTION US ON THIS TEMPORARY HAZARD.