Narrative:

In crz at FL290 #1 idg disconnected itself. Maintenance 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 speed gear box. About 30 min later #1 hydraulic system failed, leaving little doubt in crew's minds that #1 high speed gear box was failing. Diverted to bos for maintenance. Landed at 425K pounds (normal maximum landing weight international) on runway 33L. Very smooth touchdown, brake application below 130 KTS to prevent heat buildup. Easy stop. Had emergency equipment stand by in case of brake fire. Gear box had failed and flight crew entered actual failures (idg and hydraulic) in log. Advised maintenance of over weight landing and brake approach speed, but as so specific discrepancy did not enter in logbook. Crew feels maintenance should have advised of possibility of high speed gear box failure when told of idg disconnect, and perhaps suggested we land to have it checked prior to ocean crossing. Flying domestic legs and checking at each stop until replacement is feasible is one thing, flying united states to europe is quite another. Note: bos had several runway 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 tower caution us on this temporary hazard.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.