Narrative:

Aircraft experienced a loud bang noise on takeoff; reported by flight attendants. The aircraft had bleed air loss and body loop EICAS messages. The bleeds automatically isolated so no bleed air to the C1 and C2 hydraulic demand pumps and hydraulic reservoir pressurization. Aft cargo heat and potable water tank pressurization also affected. Intermittent body loop 2 zone 4 shorted. Takeoff roll body loop 1 zone 3 shorted. After aircraft experienced this bleed duct failure with associated hydraulic pumps inoperative the aircraft continued on its flight plan from ZZZZ to ZZZ. Aircraft continued to its ETOPS point of entry and flew ETOPS without further investigation of cause and effect of duct failure on takeoff roll. Callback conversation with reporter revealed the following information: reporter stated when this B-777 arrived at his station from its international flight; maintenance found the large pneumatic supply duct (manifold) in the left wheel well had blown (exploded) into the wheel well. This was the loud noise the flight attendants had described they heard on takeoff. Reporter also stated that maintenance could not believe the flight crew continued on; overwater; with multiple faults showing on EICAS prior to even entering the ETOPS envelope and did not even deviate to another city. The aircraft's center hydraulic system demand pumps are pneumatic (air) driven hydraulic pumps and were inoperative with the blown pneumatic duct. Reporter believes this deviation from standard operational procedures went outside of any safe acceptable deviation practice.

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Original NASA ASRS Text

Title: A B777-200 ACFT HAS LOUD BANG ON TKOF WITH BLEED AIR LOSS AND BODY LOOP EICAS MESSAGES; LOSS OF CENTER HYD SYS C-1/C-2 DEMAND PUMPS; AFT CARGO HEAT AND POTABLE WATER PRESSURIZATION. PILOT CONTINUES INTO ETOPS ENTRY OVERWATER TO DOMESTIC DESTINATION.

Narrative: ACFT EXPERIENCED A LOUD BANG NOISE ON TKOF; REPORTED BY FLT ATTENDANTS. THE ACFT HAD BLEED AIR LOSS AND BODY LOOP EICAS MESSAGES. THE BLEEDS AUTOMATICALLY ISOLATED SO NO BLEED AIR TO THE C1 AND C2 HYD DEMAND PUMPS AND HYD RESERVOIR PRESSURIZATION. AFT CARGO HEAT AND POTABLE WATER TANK PRESSURIZATION ALSO AFFECTED. INTERMITTENT BODY LOOP 2 ZONE 4 SHORTED. TKOF ROLL BODY LOOP 1 ZONE 3 SHORTED. AFTER ACFT EXPERIENCED THIS BLEED DUCT FAILURE WITH ASSOCIATED HYD PUMPS INOP THE ACFT CONTINUED ON ITS FLT PLAN FROM ZZZZ TO ZZZ. ACFT CONTINUED TO ITS ETOPS POINT OF ENTRY AND FLEW ETOPS WITHOUT FURTHER INVESTIGATION OF CAUSE AND EFFECT OF DUCT FAILURE ON TKOF ROLL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED WHEN THIS B-777 ARRIVED AT HIS STATION FROM ITS INTERNATIONAL FLIGHT; MAINT FOUND THE LARGE PNEUMATIC SUPPLY DUCT (MANIFOLD) IN THE LEFT WHEEL WELL HAD BLOWN (EXPLODED) INTO THE WHEEL WELL. THIS WAS THE LOUD NOISE THE FLIGHT ATTENDANTS HAD DESCRIBED THEY HEARD ON TKOF. REPORTER ALSO STATED THAT MAINT COULD NOT BELIEVE THE FLIGHT CREW CONTINUED ON; OVERWATER; WITH MULTIPLE FAULTS SHOWING ON EICAS PRIOR TO EVEN ENTERING THE ETOPS ENVELOPE AND DID NOT EVEN DEVIATE TO ANOTHER CITY. THE ACFT'S CENTER HYD SYS DEMAND PUMPS ARE PNEUMATIC (AIR) DRIVEN HYD PUMPS AND WERE INOP WITH THE BLOWN PNEUMATIC DUCT. REPORTER BELIEVES THIS DEVIATION FROM STANDARD OPERATIONAL PROCEDURES WENT OUTSIDE OF ANY SAFE ACCEPTABLE DEVIATION PRACTICE.

Data retrieved from NASA's ASRS site as of January 2009 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.